Galangal

What is Galangal?

The published human evidence for galangal as a focus aid comes from one branded water extract of Alpinia galanga rhizome, EnXtra, tested at 300 mg per dose in four company-linked trials published from 2017 to 2026. The extract was developed by Enovate Biolife of Mumbai, patented in the United States as US 10,946,059 (granted 16 March 2021), and is marketed in North America by OmniActive Health Technologies. All four enrolled healthy adults, at least three of them limited to habitual caffeine users, and three of the four included a caffeine arm.

Galangal itself is not one plant. Three rhizomes of the family Zingiberaceae are sold under overlapping names. Greater galangal, Alpinia galanga (L.) Willd., is the large, pale, piney rhizome of Thai and Indonesian cooking and the species in EnXtra. Lesser galangal, Alpinia officinarum Hance, native to southern China and Indochina, is smaller (rhizome diameter 8 to 12 mm in the PROSEA plant resources handbook), more pungent, and is the galangal of European pharmacy, the German Commission E, the Chinese Pharmacopoeia and the US food-additive regulations. Kencur, Kaempferia galanga L., is a different genus altogether, a squat aromatic rhizome whose essential oil is dominated by ethyl p-methoxycinnamate. The 1918 Dispensatory of the United States already recorded the split: "Galanga major" came from A. galanga and "Galanga minor" from A. officinarum, while the National Formulary IV defined official galangal as the dried rhizome of A. officinarum alone.

Common Names

• Greater galangal, Thai galangal, Thai ginger, blue ginger, kha (Thai), lengkuas (Malay and Indonesian), Kulanjan or Kulinjan, Rasna (Indian trade names): Alpinia galanga

• Lesser galangal, Chinese galangal, Gao Liang Jiang (Chinese Pharmacopoeia, Alpiniae Officinarum Rhizoma), Galgant (German), Galangae rhizoma (Commission E): Alpinia officinarum

• Kencur (Indonesian), cekur (Malay), sand ginger, aromatic ginger, Shan Nai (Chinese): Kaempferia galanga

• Red galangal: Alpinia purpurata, a different species with a distinct metabolite profile, sometimes sold in chopped or powdered form where it can be confused with white galangal

• EnXtra, E-AG-01, AGRE: trade and code names for the Enovate water extract of A. galanga rhizome

Primary Active Compounds

• 1'S-1'-Acetoxychavicol acetate (ACA), the pungent phenylpropanoid ester of A. galanga rhizome, with the related 1'S-1'-acetoxyeugenol acetate. ACA is poorly water soluble and unstable in aqueous solution, where it undergoes hydrolysis or isomerization (Azuma and colleagues, 2011).

• Galangin (3,5,7-trihydroxyflavone), the marker flavonol for lesser galangal: the 2020 Chinese Pharmacopoeia requires not less than 0.70 percent galangin in dried Gao Liang Jiang. Kaempferide and kaempferol accompany it.

• Diarylheptanoids, historically lumped together as "galangol," some of them pungent

• Volatile oil: 0.5 to 1 percent of lesser galangal rhizome per the German Medpharm monograph, mainly sesquiterpenes, with 1,8-cineole used as a thin-layer identity marker. In A. galanga rhizome oil, Chaiyana and colleagues (Chiang Mai, 2022) found methyl cinnamate and 1,8-cineole as the major components.

• Ethyl p-methoxycinnamate and ethyl cinnamate, the signature esters of kencur: 28.4 to 70.0 percent and 11.5 to 26.6 percent of Indian kencur oil in the range tabulated by Wang and colleagues' 2021 review

• Water-soluble polyphenols and polysaccharides, the fractions the EnXtra patent actually specifies

Key Note

The branded cognition extract is greater galangal, the US spice regulation names lesser galangal, the German traditional-use approval names lesser galangal, and the 2024 Nutrients review of galangal for brain disorders (Abd Rahman and colleagues) covers lesser galangal. A bottle that says only "galangal root" has not said which of the three plants, or which of their chemistries, it holds.

Galangal is a set of rhizome spices with one heavily marketed extract, and the extract and the spice are not interchangeable.

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Primary Functions & Benefits

Galangal is sold for four things: alertness without (or alongside) caffeine, digestion, male reproductive health, and joint comfort. Each rests on a different species or preparation, and only the first has more than one controlled human trial behind it.

Alertness and attention (greater galangal, EnXtra only)

Four company-linked trials of the same 300 mg water extract, summarized under Benefits and Research Status. No published trial found in this research measured attention or alertness in people given plain galangal powder, a culinary amount of fresh rhizome, or any lesser galangal product.

Digestion (lesser galangal, regulatory only)

Commission E published a positive monograph on Galangae rhizoma, the rhizome of A. officinarum, in the Bundesanzeiger of 18 September 1986 (No. 173), corrected 13 March 1990, for dyspeptic complaints and loss of appetite. It is a traditional-use approval. This research found no controlled human trial of either galangal species for dyspepsia.

Male reproductive outcomes (both Alpinia species, small trials)

One trial of lesser galangal extract and one of a pomegranate and greater galangal tablet reported higher sperm counts or motile sperm numbers over 3 months, and one Iranian trial of greater galangal extract reported better erectile function scores in men taking SSRI antidepressants. These are single trials, two of them in combination or add-on designs.

Joint pain (combination only)

The largest oral galangal-containing trial found for this issue, 261 patients with knee osteoarthritis, tested a standardized extract of two Zingiberaceae species together. It cannot be read as a galangal result.

Forms & Standardization

Six kinds of material reach consumers under the galangal name, and they differ in species, solvent and marker.

EnXtra (E-AG-01), greater galangal water extract

The patent describes dried, powdered A. galanga rhizome extracted first with cold water (0 to 25 degrees C) and then through three cycles at 70 to 80 degrees C. Its claims cover 100 to 900 mg of a water extract "free of methyl eugenol" (specified as less than 1 ppm) for improving cognitive performance, with 300 mg as the preferred embodiment, carried on microcrystalline cellulose or maltodextrin. The patent's Table 1 shows how much the solvent changes the product: cold-water extracts ran 4.15 to 5.86 percent polyphenols and 24.90 to 42.06 percent polysaccharides, while a 70 degree C hot-water extract ran 8.09 percent polyphenols and 13.09 percent polysaccharides. The claimed polyphenol to polysaccharide ratio is about 1:1.6 to 1:12. The patent also caps galangin at not more than 100 ppm and reports about 1 percent pyrocatechol-type tannins. It does not mention ACA at all. In short, EnXtra is specified as a polar, carbohydrate-rich fraction, and how much of the pungent ester chemistry behind most published galangal pharmacology survives in it is undisclosed.

Single-ingredient EnXtra capsules

Swanson's "Focused Attention Alpinia Galanga, Caffeine Free" carries 300 mg of enXtra extract from rhizome per capsule, one capsule a day, in a gelatin shell with rice bran, maltodextrin, magnesium stearate and silica. The page markets it as a "caffeine-free, stimulant-free alternative" that "can safely be combined with caffeine," and its label warns against use in pregnancy or while nursing.

EnXtra in pre-workouts and energy blends

OmniActive also sells EnXtra as an ingredient for energy and pre-workout formulas and promotes it for use "alone or alongside caffeine." No published trial found for this issue tested EnXtra inside a multi-ingredient blend; the published combination arms paired it with plain caffeine and nothing else.

Generic greater galangal extracts

A German-sold vegan capsule (Sunday Natural) lists "Galangal extract (Alpinia galanga), also known as Thai ginger," 200 mg of a 5:1 pure-water extract per capsule, two capsules a day with a meal, with no marker compound stated. Two capsules equal roughly 2 g of dried rhizome by the stated ratio. Nothing on that label ties it to EnXtra's specification, so the EnXtra trials do not describe it.

Lesser galangal powder and tea

The Commission E material: cut or powdered A. officinarum rhizome, 0.5 to 1 percent volatile oil, 20 to 25 percent starch, with galangin, galangin-3-methyl ether and kaempferide, per the 2003 Medpharm monograph. The Chinese Pharmacopoeia (2020) assay requires at least 0.70 percent galangin, which is 70 times the 100 ppm (0.01 percent) ceiling in the EnXtra patent. Hildegard of Bingen-branded "Galgant" capsules and tablets sold in German-speaking countries belong in this group by tradition, though the listing reviewed for this issue did not print a botanical name.

Lesser galangal extracts in trials

Kolangi and colleagues used capsules of dried A. officinarum rhizome extract at 300 mg a day, without reporting a marker content.

Combination tablets with a stated marker

The Danish Punalpin tablet combined pomegranate fruit extract (standardized to punicalagin A and B, punicalin and ellagic acid) with freeze-dried greater galangal rhizome standardized to 1'S-1'-acetoxychavicol acetate. It is one of very few galangal products whose published trial named ACA as the galangal marker.

Kencur (Kaempferia galanga)

Sold as dried slices, powder and Indonesian jamu drinks. Its oil is mostly ethyl p-methoxycinnamate, ethyl cinnamate and pentadecane, a chemistry shared by neither Alpinia species. Wang and colleagues' 2021 review cites the Chinese Pharmacopoeia dose of 6 to 9 g of Shan Nai for oral use.

What the bioavailability data say

Very little. No human pharmacokinetic study of ACA, galangin or any EnXtra constituent turned up. In human liver microsomes and hepatocytes, Otake, Hsieh and Walle (2002) found that galangin is glucuronidated 11 to 31 times more efficiently than it is oxidized, and in fresh hepatocytes from six donors glucuronidation clearly predominated, with oxidation detectable in only two. The authors concluded conjugation is the likely main fate of galangin in the body.

Food Sources

Galangal is a food first. Fresh greater galangal is the "kha" in Thai tom kha soup and the lengkuas in Indonesian and Malaysian spice pastes; dried lesser galangal is a Chinese kitchen and pharmacy spice; kencur flavors Indonesian beras kencur drinks and Southeast Asian cooking.

How much a cook actually uses

Galangal is eaten in gram amounts, so its vitamin and mineral content is beside the point. The useful comparison is with the regulatory and trial doses. The Commission E daily amount of lesser galangal, 2 to 4 g of dried rhizome, is a kitchen quantity, and at the 0.5 to 1 percent volatile oil content in the Medpharm monograph it carries about 10 to 40 mg of oil. The Chinese Pharmacopoeia range for Gao Liang Jiang is 3 to 6 g.

What cooking does to it

ACA, the pungent ester of greater galangal, is not stable in water: Azuma and colleagues reported that it hydrolyzes or isomerizes in aqueous solution, which is why researchers trying to deliver it have had to package it in cyclodextrins. A long-simmered broth is therefore a poor vehicle for intact ACA. Drying also changes the oil: in a 2022 Food Chemistry comparison by Ge and colleagues, hot-air drying, vacuum drying and freeze-drying of fresh A. galanga produced measurably different volatile profiles, and freeze-dried material retained more essential oil.

Food or extract?

For lesser galangal and the Commission E indication, the food form is the studied form. For the alertness claim, the food form is irrelevant: EnXtra is a specified water fraction, and no amount of galangal in a curry has been shown to reproduce it.

Fresh-produce hygiene

Galangal is a soil-grown rhizome often eaten lightly cooked. Jinatham and colleagues screened 20 raw vegetables from two street markets in northern Thailand in 2023 and found the protist Blastocystis in 45 percent of samples, with galangal among the positive underground crops. Wash and peel fresh rhizome.

Who Should Take Galangal

As a spice, nearly anyone without an allergy to it. As a supplement, the defensible candidates are narrow.

Reasonable to trial

• Healthy adults who want to test whether a 300 mg EnXtra capsule changes their own afternoon alertness, understanding that the published effects are modest where numbers are given, the trials are all company-linked, and the trial populations were mostly young, healthy and caffeine-habituated.

• Adults with uncomplicated, already-evaluated dyspepsia or poor appetite who want the Commission E traditional use of lesser galangal at kitchen amounts.

• Men already working with a fertility clinic who want to discuss the two small sperm-parameter trials with their clinician, recognizing that one tested a combination tablet.

Who should not use it as a substitute

• Anyone with daytime sleepiness, fatigue or attention problems that are new, worsening or affecting driving or work. Those symptoms have medical causes (sleep apnea, anemia, thyroid disease, depression, medication effects) that an alertness capsule would mask.

• Children and adolescents. Every EnXtra trial enrolled adults, and the single-ingredient product reviewed here is labeled for adults only.

Who Should AVOID or Use Caution

Contraindications

• Galangal allergy. Hong and Chang at Tzu Chi General Hospital in Taiwan reported in Contact Dermatitis (2006) a woman who developed localized contact dermatitis and then a generalized erythema multiforme-like eruption after applying herbal remedies; patch testing found an allergen in both fresh and dried A. galanga. Anyone who reacted to a galangal poultice, liniment or balm should not swallow galangal supplements.

• Pregnancy, for medicinal amounts. Kaushik and colleagues' 2011 review lists emmenagogue and abortifacient uses among galangal's traditional applications, no human pregnancy safety data exist for any extract, and the EnXtra product reviewed here is labeled "Do not use if pregnant or nursing." Culinary use is a different exposure.

• Combining an EnXtra product with additional caffeine sources beyond a person's usual intake. The 12-week EnXtra trial gave 400 mg of caffeine a day in its combination arm, the same figure FDA cites as the daily amount not generally associated with negative effects in healthy adults. Stacking a galangal-plus-caffeine pre-workout on top of coffee can exceed it.

Use Caution

• Drugs cleared or activated by CYP1A2, CYP2D6 or CYP3A4, especially narrow-margin ones: theophylline, clozapine and tizanidine (CYP1A2); tamoxifen and codeine activation and metoprolol (CYP2D6); tacrolimus, cyclosporine and simvastatin (CYP3A4). Purified ACA (isolated from the related Alpinia conchigera) inhibited all three enzymes in vitro, and its CYP2D6 inhibition was mechanism based. No human interaction study exists, so this is a reason to tell the prescriber, not a demonstrated interaction.

• Anticoagulant and antiplatelet drugs (warfarin, apixaban, clopidogrel, aspirin) when the product is kencur. An ethanolic Kaempferia galanga extract prolonged bleeding time and improved survival in a mouse thrombosis model with potency approaching aspirin at the top dose. The finding is animal-only and specific to kencur.

• SSRIs and other antidepressants. The only galangal trial in medicated patients added 500 mg of A. galanga extract to SSRIs for 4 weeks without liver or kidney marker changes, but 60 men for one month is not a drug interaction safety record.

• Anxiety disorders, insomnia and cardiac rhythm problems, when the galangal product also contains caffeine. The caffeine dose, not the galangal, is usually the larger pharmacological load in those products.

• Gastric sensitivity. Galangal is pungent, and the 261-patient osteoarthritis trial of an A. galanga-containing extract recorded gastrointestinal adverse events in 59 treated patients against 21 on placebo.

Critical Safety Point

When a galangal product is sold for energy, check whether it also contains caffeine; if it does, the hazards people feel (jitteriness, palpitations, broken sleep) usually come from the caffeine. Read the caffeine milligrams before the galangal line, add up every caffeine source in the day, and stop the product if palpitations, chest pain, fainting or severe anxiety appear. For the galangal itself, the documented human harm is skin allergy; the theoretical one is CYP-mediated drug interaction.

Recommended Dosages

No dose of galangal has been established for alertness, digestion or any other use. The figures below are a German traditional-use posology, a pharmacopoeia range, and the preparations used in specific trials. Each applies only to the material it describes.

Culinary galangal (all three species)

Kitchen amounts carry no recognized limit for adults who are not allergic.

Lesser galangal rhizome, Commission E (adults, dyspeptic complaints, loss of appetite)

2 to 4 g of dried rhizome a day. As tea, the Medpharm monograph gives 0.5 to 1 g (about a third of a teaspoon) in 150 mL of hot water, steeped 5 to 10 minutes, one cup about 30 minutes before a meal. The Chinese Pharmacopoeia range for Gao Liang Jiang is 3 to 6 g. These are traditional amounts, not doses established in dose-finding trials.

EnXtra (adults, as tested)

300 mg of the E-AG-01 water extract per dose. The single-dose trials gave one 300 mg capsule; the 12-week trial gave 600 mg a day, with or without 400 mg of caffeine a day, according to trade coverage of the paper. The Swanson product label directs one 300 mg capsule a day. Generic greater galangal extracts are a different material, and the EnXtra figures do not transfer to them.

Preparations used in other human trials

• Male infertility: dried A. officinarum rhizome extract capsules, 300 mg a day for 3 months. Kolangi 2018, 76 included, 60 analyzed (31 active, 29 placebo).

• Subfertile men: Punalpin tablets (pomegranate fruit extract plus freeze-dried A. galanga rhizome standardized to ACA) daily for 3 months. Fedder 2014, 70 randomized, 66 completed.

• SSRI-associated erectile dysfunction: 500 mg A. galanga extract tablets, taken with milk on an empty stomach, for 4 weeks. Akbarzadeh 2023, 60 men.

• Long COVID symptoms: 4,500 mg a day of a five-plant extract (Citrus aurantifolia, Tiliacora triandra, Cannabis sativa, A. galanga, Piper nigrum) for 7 days. Lukkunaprasit 2024, 66 randomized.

• Knee osteoarthritis: EV.EXT 77, a two-species extract containing A. galanga, twice daily for 6 weeks. Altman and Marcussen 2001, 261 enrolled, 247 evaluable.

Kencur

The Chinese Pharmacopoeia figure for Shan Nai, as cited in Wang 2021, is 6 to 9 g of dried rhizome, usually as a decoction. No controlled human trial of oral kencur turned up in this research.

Duration

The longest controlled exposures are 12 weeks for EnXtra and 3 months for the two sperm-parameter trials. No longer controlled exposure to any galangal preparation turned up in this research.

Timing & Administration

Lesser galangal before meals. The monograph pattern is a cup of tea about 30 minutes before eating, matching the appetite and dyspepsia indication.

EnXtra in the morning or early afternoon. Trial measurements ran 1, 3 and 5 hours after the dose, and trade coverage of the 2023 crossover described dosing after lunch. Sleep was a measured safety outcome: in the 12-week trial, Pittsburgh Sleep Quality Index scores did not change in any arm and Epworth daytime sleepiness scores did not change significantly.

Fresh rhizome late in cooking. ACA is unstable in water, so adding sliced galangal late, or grinding it into a paste, is the likelier way to keep the pungent chemistry than simmering it for hours.

Timeline of Effects

Hours, for EnXtra alertness. The founding trial measured at 1, 3 and 5 hours. OmniActive's account of the 2023 crossover in 62 adults reports better Symbol Digit Coding correct responses at 30 minutes (about three times greater, comparator unstated) and Alertness Rating Scale change about four times placebo at 2 hours, with simple reaction time benefits up to 5 hours; the paper appeared in Advances in Complementary & Alternative Medicine, and those multiples come from the sponsor's release rather than from a table checked for this issue.

Weeks, for whether the effect persists. The 12-week trial reported significant alertness and calmness gains on the Bond and Lader mood scales at about 180 minutes after dosing that, according to its authors, held through the study without habituation. The 2026 trial added a 28-day parallel stage in 127 participants; the company reports sustained alertness and fatigue benefits there, while caffeine alone helped at 1 hour but not at 3 or 5 hours.

Two to four weeks, for the SSRI erectile function trial. International Index of Erectile Function scores separated from placebo by week 2 (14.1 against 11.4, p = 0.015) and widened by week 4 (17.4 against 13.7, p = 0.001).

Three months, for sperm parameters. Both sperm trials ran 12 weeks, roughly one full cycle of sperm production.

Six weeks, for the osteoarthritis combination. The primary responder analysis was taken at 6 weeks.

When to call it a failed trial. For an EnXtra product, the published effects were measured within hours of a dose, so a week of daily use with no noticeable difference is a fair answer. For lesser galangal tea, a few days of pre-meal use is a fair test of an appetite or fullness effect. For sperm parameters, only a repeat semen analysis after about 3 months can say, and that decision belongs inside a fertility workup.

Benefits of Taking Galangal

Alertness, from one extract, with modest and company-reported effects. The 2017 crossover (Journal of the American College of Nutrition, registered as NCT02816827) enrolled 59 adults aged 18 to 40 with moderate habitual caffeine intake, normal weight, and low anxiety and depression scores, and tested placebo, 300 mg E-AG-01, 200 mg caffeine, and both together on separate visits. The extract arm's Attention Network Test alertness score rose 11.65, 12.50 and 12.62 ms from baseline at 1, 3 and 5 hours. The combination arm cut mean response time on a vigilance test by 15.55 ms at 3 hours (p = 0.026), and the authors concluded the pairing "impedes the caffeine crash." The 2020 follow-up in the same journal randomized 70 moderate caffeine users (69 completed, per trade reports) to EnXtra at 600 mg a day, the same plus 400 mg caffeine a day, or placebo for 12 weeks (daily totals from trade coverage; the abstract gives no doses); it reported higher Bond and Lader alertness and calmness scores in both EnXtra arms against placebo (p less than 0.001) and no change in QT interval, blood pressure or heart rate. The abstract gives no effect sizes. Two later trials, both linked to OmniActive, extended this: Mohan Muttanahally Eraiah and colleagues' 62-person crossover in 2023, and Pandit and colleagues' two-stage trial in the Open Access Journal of Clinical Trials in 2026 (128 in a single-dose crossover, 127 in a 28-day parallel stage, sleep-restricted habitual caffeine users aged 18 to 40). Neither appeared in a PubMed search for "EnXtra" run for this issue, and the press materials for both give no p-values.

Sperm parameters, two small trials. Fedder and colleagues in Denmark (PLoS One, 2014, NCT01357044) randomized 70 men whose semen did not meet sperm-bank standards to Punalpin or placebo for 3 months; 66 completed (34 and 32). The average total motile sperm count rose 62 percent on the tablets (23.4 to 37.8 million) against 20 percent on placebo (p = 0.026), with no change in morphology. Two coauthors were affiliated with Nerthus ApS, a Danish company in Lejre. Kolangi and colleagues in Babol, Iran (Andrologia, 2018) gave 300 mg a day of lesser galangal extract or placebo to men with idiopathic infertility for 12 weeks; in the 60 analyzed, mean sperm count in the treated group went from 52 to 71 million per mL (p = 0.043) and normal morphology from 14.34 to 19 percent (p less than 0.001). The abstract reports those as before-and-after changes within the treated group.

SSRI-associated erectile dysfunction, one pilot. Akbarzadeh and colleagues at Mashhad University of Medical Sciences randomized 60 men on SSRIs with new-onset sexual dysfunction to 500 mg A. galanga extract tablets or placebo for 4 weeks in a triple-blind design (IRCT20101130005280N41). International Index of Erectile Function scores rose from 11.2 to 17.4 on the extract and from 10.6 to 13.7 on placebo (repeated-measures p less than 0.001, Cohen's d 0.49). Depression and anxiety scores fell equally in both arms. The authors called it a pilot, recruited by convenience sampling, and the extract preparation was not standardized to any marker.

Knee osteoarthritis, a combination that included galangal. Altman and Marcussen (Arthritis and Rheumatism, 2001) randomized 261 patients to EV.EXT 77, a standardized extract of ginger (Zingiber officinale) and A. galanga, or placebo for 6 weeks. Among 247 evaluable, 63 percent of the extract group and 50 percent of the placebo group were responders for knee pain on standing (p = 0.048). Galangal's separate contribution is unknown.

Long COVID, a five-plant mixture. Lukkunaprasit and colleagues at Rangsit University randomized 66 Thai adults to a five-plant combined extract (4,500 mg a day) containing A. galanga, or placebo for 7 days. C-reactive protein did not change (median difference minus 0.05 mg/L), the total symptom score fell 4.00 points more on the mixture (95 percent CI 0.42 to 7.58) on a newly built 57-point questionnaire, and quality of life scores did not differ.

Digestion, by tradition. The Commission E approval for lesser galangal stands without a controlled trial underneath it.

Potential Negatives & Side Effects

Skin allergy, including generalized reactions. The Hong and Chang case shows galangal can sensitize through the skin and then produce a whole-body eruption. Topical Southeast Asian herbal balms and liniments are the realistic exposure route.

Gastrointestinal upset. In the 261-patient osteoarthritis trial, 59 patients on the galangal-containing extract had gastrointestinal adverse events against 21 on placebo, mostly mild. That is the largest adverse event difference found in this research, and it came from a combination.

Tolerability in the EnXtra trials is thinly reported. The 2018 reanalysis of the 2017 trial states only that adverse events "were planned to be reported" and reports none. The patent's account of the same trial records six dropouts among 59 (four withdrawals of consent, two lost to follow-up) and, as read for this issue, links two withdrawals to safety concerns it does not describe. The 12-week trial reported no ECG, blood pressure or heart rate changes.

The caffeine in the combination. Where a galangal energy product also contains caffeine, insomnia, tremor, palpitations and anxiety are caffeine effects, and no published EnXtra trial reviewed here showed the extract preventing them.

Laboratory and hormone effects in animals. Qureshi and colleagues' mouse study found a significant rise in red blood cell levels after 90 days of ethanolic A. galanga extract and increased sexual organ weights and sperm counts in males. These are not established human effects, but they are reasons to report supplement use before blood tests or fertility workups.

Deficiency Symptoms

What galangal deficiency addresses: nothing. No human requirement exists for ACA, galangin, ethyl p-methoxycinnamate, or any polysaccharide or polyphenol fraction of these rhizomes, and no syndrome follows from never eating them. Galangin is a flavonol that also serves as a marker compound of honey, and kaempferol is widespread in vegetables, so even the marker compounds are not galangal-exclusive.

Bottom line: galangal is optional. A tired person needs the cause of the tiredness found, not a rhizome extract.

Toxicity Symptoms

At high intake: galangal has no characterized toxic syndrome in people. Repeated doses in the controlled human studies reviewed here include 600 mg a day of EnXtra for 12 weeks and 4,500 mg a day of a five-plant mixture containing galangal for 7 days, without serious adverse events reported. Animal data are reassuring at their own doses. Qureshi and colleagues gave mice ethanolic A. galanga extract at single doses up to 3 g/kg and 100 mg/kg a day for 90 days without significant mortality, in a study that tested turmeric extract in parallel. Shanmugasundaram's 90-day OECD 408 study in Sprague Dawley rats, from Vedic Lifesciences in Mumbai, found no treatment-related adverse effects at up to 3,000 mg/kg a day of EnXtra, set that as the no-observed-adverse-effect level, and derived an acceptable daily intake of 1,800 mg a day for humans. Kencur ethanol extracts reached a maximum tolerated single oral dose of 5,000 mg/kg in rats with no deaths in Kanjanapothi's study, as summarized by Wang 2021. None of these numbers is a human dose.

One mechanistic flag concerns galangin. Silva and colleagues (Mutation Research, 1997) showed that rat liver cytochromes P450 convert galangin to kaempferol and then quercetin, and that these metabolites, not galangin itself, were responsible for mutagenicity in the Salmonella reversion assay and chromosomal aberrations in hamster V79 cells. That is an in vitro finding with no human outcome attached, and it applies to galangin-containing rhizome powders more than to an extract capped at 100 ppm galangin.

A second flag concerns methyl eugenol, which IARC classified in 2023 as probably carcinogenic to humans (Group 2A) on animal and mechanistic evidence. It occurs in greater galangal rhizome oil (3.23 percent in a Chiang Mai sample, Khumpirapang and colleagues, 2022), which is why the EnXtra patent specifies under 1 ppm. Galangal essential oils and solvent extracts that state no methyl eugenol limit carry no such assurance.

Signs to reduce or stop: a rash, blistering or hives after skin contact or ingestion (allergy, which can generalize); persistent heartburn or abdominal pain; palpitations, chest pain, tremor or insomnia on a product that also contains caffeine; any unexplained change in how a regular medication works, especially one cleared by CYP1A2, CYP2D6 or CYP3A4.

General note: galangal's documented human harm is allergic. Most other risks attached to galangal products come from their caffeine, their dose stacking or their unstated species.

How Galangal Works

For EnXtra, the proposed mechanisms come from the sponsor's mouse work. Sahin and colleagues, with two OmniActive research staff among the authors, gave mice a water-soluble A. galanga extract at 61.25 or 205.50 mg/kg alongside 25 mg/kg caffeine (Pharmaceuticals, 2024). The higher dose raised brain dopamine and serotonin against caffeine alone (p less than 0.0001) and, unexpectedly for an alertness ingredient, increased total deep sleep duration compared with the caffeine group. By the standard body-surface conversion, 205.50 mg/kg in a mouse corresponds to roughly 1 g for a 60 kg adult, more than three times the 300 mg human dose. No human study has measured dopamine, serotonin or any brain imaging marker after EnXtra; the 2018 reanalysis proposed reduced alpha-band power as a mechanism and acknowledged it would need a prospective imaging study to confirm.

ACA damps allergic and inflammatory signaling in cells and animals. Matsuda and colleagues at Kyoto Pharmaceutical University isolated ACA and 1'S-1'-acetoxyeugenol acetate from an 80 percent aqueous acetone extract of A. galanga rhizome and found they blocked antigen-IgE-mediated mast cell degranulation (IC50 15 and 19 micromolar) and passive cutaneous anaphylaxis in mice. The same group measured ACA inhibiting nitric oxide production in activated mouse macrophages at an IC50 of 2.3 micromolar. Sok and colleagues (2021) showed ACA suppresses NLRP3 inflammasome activation through mitochondrial reactive oxygen species. These effects need ACA, which a water extract may carry little of and which falls apart in water.

Cholinesterase inhibition by the volatile oil, in a test tube. Chaiyana and colleagues measured A. galanga essential oil inhibiting acetylcholinesterase at an IC50 of 24.6 micrograms per mL and butyrylcholinesterase at 825.4. That is a cell-free enzyme assay, and it says nothing about what reaches the human brain.

Lesser galangal neuroprotection is preclinical. The 2024 Nutrients review by Abd Rahman and colleagues collected in vitro and animal evidence that A. officinarum reduces oxidative stress and apoptosis, promotes neurite outgrowth and modulates neurotransmitters, and concluded that clinical studies are still needed. It is the wrong species for the EnXtra claim and has no human outcome of its own.

Galangin acts on xenobiotic metabolism. Ciolino and Yeh at the National Cancer Institute (1999) found galangin to be a potent noncompetitive inhibitor of CYP1A1 activity in MCF-7 breast cancer cells and an aryl hydrocarbon receptor agonist and antagonist. Human liver microsomes oxidize galangin to kaempferol mainly through CYP1A2, with a contribution from CYP2C9 (Km 9.5 micromolar).

Kencur's esters act on smooth muscle. Ethyl cinnamate from K. galanga relaxed isolated vascular tissue contracted by potassium or phenylephrine (IC50 about 0.3 and 0.38 mM), via reduced calcium influx and endothelial nitric oxide and prostacyclin release, per Wang 2021. Hexane extracts, ethyl p-methoxycinnamate and ethyl cinnamate also showed sedative activity in mice.

Synergistic Supplements

Caffeine (the only combination tested with EnXtra)

The case for the pairing rests on the 2017 crossover. In the patent's per-protocol tables, caffeine alone raised alertness by 8.97 ms at 1 hour and then fell to 1.23 ms below baseline at 3 hours, which the inventors labeled a "caffeine crash." The combination arm rose 10.27 ms at 1 hour and sat 0.68 ms below baseline at 3 hours, so adding the extract did not keep the alertness score above baseline either. What the combination did show was faster psychomotor vigilance response times than placebo at 1, 3 and 5 hours (p = 0.01, 0.04 and 0.01), a result the extract alone did not reproduce (p = 0.13, 0.73 and 0.60). The 2026 trial is said to confirm a combination advantage over 28 days; its numbers were not available for this issue. Dedicated caffeine sources such as green tea, guarana and yerba mate have their own issues in this archive.

Pomegranate fruit extract (Punalpin)

The one sperm-motility result for greater galangal came from this pairing, so the galangal share of the effect is unknown.

Five-herb Persian compound honey syrup

An Iranian trial of a honey syrup containing galangal with cinnamon, saffron, cardamom and one other rhizome reported better COPD questionnaire and FEV1 results over 8 weeks in 76 patients (Poursaleh and colleagues, Tanaffos, 2022). It is a formulation result in which galangal is one of five plants.

What has not been tested

No published trial found here tested EnXtra with L-theanine, B vitamins, tyrosine or any other common nootropic or pre-workout ingredient. A stack's label claims about synergy are assertions, not data.

Interactions & What NOT to Take

Drugs cleared by CYP1A2, CYP2D6 or CYP3A4. Haque and colleagues at the University of Malaya (Phytomedicine, 2017) found purified ACA moderately inhibited CYP1A2 (IC50 4.50 micromolar), CYP2D6 (7.50) and CYP3A4 (9.50) among nine human enzymes, competitively for CYP1A2 and CYP3A4 and mechanism based for CYP2D6. In Subehan and colleagues' 2006 screen of 30 Indonesian plants in human liver microsomes, a methanol extract of A. galanga rhizome increased CYP2D6 inhibition by more than 30 percent after preincubation, but time-dependent inhibition was confirmed only for other plants in the panel. In rats given galangin daily for 8 weeks, Ma and colleagues found lower exposure to probe drugs for CYP1A2 and CYP2B3 and higher exposure for CYP2C13 and CYP3A1. On the other side, Ankaferd Blood Stopper, a Turkish topical product with lesser galangal among five plants, did not change CYP1A1, CYP1A2, CYP2E1 or CYP3A4 activity or expression in HepG2 cells. No human interaction study with a named drug exists for any galangal preparation, so the practical rule is disclosure to the prescriber for narrow-margin drugs: theophylline, clozapine, tizanidine, tamoxifen, codeine, tacrolimus, cyclosporine.

Caffeine itself. Caffeine is cleared mainly by CYP1A2, the enzyme ACA inhibited most potently in vitro. No EnXtra trial measured caffeine blood levels, so whether the combination raises caffeine exposure is unknown. It is one more reason not to stack combination products.

SSRIs and other serotonergic drugs. The 4-week Iranian trial added A. galanga extract to SSRIs without reported serotonergic toxicity or liver marker change, and the sponsor's mouse work reported raised brain serotonin. Neither settles the question; tell the prescriber.

Anticoagulants, for kencur products. The mouse antithrombotic finding for K. galanga extract is reason to avoid medicinal kencur doses with warfarin, apixaban or clopidogrel, and before surgery.

Stimulant medications. Anyone taking methylphenidate, amphetamine salts or modafinil should not add a galangal-plus-caffeine energy product without the prescriber's input; the caffeine alone adds stimulant load, and the EnXtra trials enrolled healthy volunteers.

Quality, Testing & Adulteration

Documented species substitution

• India: Upadhye and colleagues at the Agharkar Research Institute (2018) reported that traders substitute Alpinia calcarata and A. officinarum for A. galanga because of demand, and built an HPTLC fingerprint to tell them apart. Galangin in their methanolic extracts ran 7.67 mg/g for A. galanga, 5.77 for A. officinarum and 4.31 for A. calcarata, so a galangin number alone cannot identify the species.

• Indonesia: Hernadi and colleagues (2026) built an LC-MS method because dried, chopped or powdered white galangal (A. galanga) and red galangal (A. purpurata) are hard to tell apart, citing misidentification and fraud.

• Germany: the Medpharm monograph lists Kaempferia galanga and other Alpinia species as known confusions for lesser galangal.

• Sri Lanka: Wijayasiriwardena and Premakumara (2012) separated A. calcarata from A. galanga powder by microscopy; diamond-shaped silica crystals occurred only in A. galanga.

Authentication methods that exist

A 2026 study from Herbalife's analytical laboratories combined chloroplast DNA barcoding with HPTLC and HPLC to authenticate A. galanga rhizomes and extracts and confirmed galangin by retention time in every sample. OmniActive describes EnXtra as made from DNA-authenticated rhizome. That study recovered usable DNA from extracts as well as raw rhizome, so a supplier can be asked for both kinds of evidence.

What a useful specification sheet contains

• The full botanical name with authority: Alpinia galanga (L.) Willd., Alpinia officinarum Hance or Kaempferia galanga L.

• Plant part (rhizome) and extraction solvent, plus the drug-to-extract ratio for any extract

• A named marker with method: polyphenols and polysaccharides for EnXtra-type water extracts; galangin by HPLC against the 0.70 percent Chinese Pharmacopoeia floor for lesser galangal powder; ACA where a lipophilic extract claims pungent activity

• Methyl eugenol, which the EnXtra patent sets at under 1 ppm

• Lead, cadmium, arsenic and mercury, plus microbial counts for powders made from soil-grown rhizome

What the buyer can check from the bottle

• Does the panel name a species, or only "galangal root"? Only a species tells you which evidence applies.

• For an alertness product, is the extract identified as EnXtra or E-AG-01 at 300 mg? Any other galangal extract has no published alertness trial.

• How much caffeine is in a serving, and is it in "proprietary blend" form? A blend that hides the caffeine milligrams cannot be added to the day's other sources.

What third-party seals do and do not say

A USP Verified mark confirms that the label's ingredients are present in the stated amounts and within contaminant limits; NSF Certified for Sport adds screening for banned substances. It does not confirm that an alertness claim is supported, and it does not convert an unnamed "galangal" into a stated species.

Special Considerations

Habitual caffeine users are most of the people studied. Three of the four EnXtra trials enrolled only moderate or habitual caffeine users. How the extract behaves in caffeine-naive people, older adults or anyone with a medical condition is untested. A registered 79-person, 14-day pilot in adults aged 30 to 70 comparing an A. galanga formulation with theacrine and caffeine (NCT05170113, completed May 2022, sponsored by Supplement Formulators, Inc.) has no published results that this research could find.

The stimulant tradition belongs to kencur. In the Thai ethnomedical record summarized by Wang 2021, the rhizome used "as cardiotonic and central nervous system (CNS) stimulants" was Kaempferia galanga (Mokkhasmit, 1971), not greater galangal. The branded alertness extract uses a different genus from the traditional stimulant.

Pregnancy and lactation. No human data. Traditional emmenagogue and abortifacient uses argue against medicinal doses; culinary use in food cultures where galangal is everyday cooking is a different exposure. No lactation study exists.

Regulatory status in the United States. 21 CFR 182.10 and 182.20 list galangal as a GRAS spice and essential oil under A. officinarum only. FEMA lists galangal root extract as flavor ingredient 2499 for both A. officinarum and A. galanga. The 2022 rat toxicology paper says EnXtra is already GRAS in the US without saying whether FDA was notified; this research did not find an FDA GRAS notice for it.

Research Status & Evidence Quality

Tier 1, German traditional-use monograph: lesser galangal for dyspeptic complaints and loss of appetite, Commission E 1986. Not a trial result.

Tier 2, randomized human trials of one branded extract: EnXtra for alertness, four trials of 59 to 128 participants per stage, all funded by or authored with the developer or marketer.

Tier 3, single small randomized trials: lesser galangal extract and sperm count (60 analyzed), A. galanga extract and SSRI-associated erectile dysfunction (60 men, 4 weeks).

Tier 4, combination products: Punalpin for sperm motility, EV.EXT 77 for knee osteoarthritis, a five-plant extract for long COVID, a Persian honey syrup for COPD. None isolates galangal.

Tier 5, animal and in vitro: neuroprotection (lesser galangal), dopamine and sleep (EnXtra in mice), anti-allergic and anti-inflammatory activity (ACA), cholinesterase inhibition (oil), CYP inhibition (ACA, galangin).

Research Limitations

The alertness trials are short, mostly young, healthy, caffeine-habituated and sponsor-linked, report within-group changes alongside between-group tests, and in the founding trial rely on per-protocol data. Two of the four (2023 and 2026) did not turn up in PubMed under brand, author or topic searches. No trial compared EnXtra with another galangal extract or with lesser galangal, so the claim that this specific water fraction is what matters is untested. Across the rest of the literature, species are often reported only as "galangal," markers are rarely stated, and no human pharmacokinetic study of any galangal constituent was found.

Summary & Key Takeaways

Bottom Line

Galangal is three rhizomes sold under one word: greater galangal (Alpinia galanga), lesser galangal (A. officinarum) and kencur (Kaempferia galanga). The supplement aisle's alertness claim belongs to a single 300 mg water extract of greater galangal, EnXtra, backed by four company-linked trials in habitual caffeine users with small reported effects. The traditional-use approvals and US spice listing belong to lesser galangal. Any "galangal root" bottle that does not name its species has not told you which body of evidence it borrows.

Key Safety Points

• Documented human harm is allergic: a generalized erythema multiforme-like eruption after topical A. galanga use.

• In combination products the caffeine is usually the bigger risk. Count every caffeine source in the day.

• ACA inhibits CYP1A2, CYP2D6 and CYP3A4 in vitro; tell the prescriber before taking galangal extracts with narrow-margin drugs.

• Avoid medicinal doses in pregnancy and while breastfeeding.

• Kencur extract prolonged bleeding time in mice; avoid medicinal kencur with anticoagulants or before surgery.

• Greater galangal oil contains methyl eugenol (IARC Group 2A); avoid concentrated oils and extracts with no stated methyl eugenol limit.

Special Note

The most revealing document in galangal's evidence file is a patent. US 10,946,059 tabulates its own trials more completely than the abstract that made the ingredient famous, including the per-protocol counts and an earlier trial this research found in no journal. Its claims describe a water extract nearly free of the galangin that defines lesser galangal and silent on the ACA that defines greater galangal. It is free to read, and it is the best label galangal has.

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Researched and drafted with AI assistance. Every claim verified against primary sources and human-reviewed before publication. Last reviewed: October 26, 2026. Corrections: reply to any issue.

Everything here is educational, and none of it is medical advice. Anyone taking prescription medication, pregnant or breastfeeding, or living with a diagnosed condition should talk to a clinician before adding galangal supplements or energy products.