Black Ginger (Kaempferia parviflora / Krachaidum / Thai Ginseng)

Kaempferia parviflora Wall. ex Baker (Zingiberaceae)
Evidence Level
Limited
3 Clinical Trials
8 Documented Benefits
2/5 Evidence Score

Kaempferia parviflora (also called Black Ginger, Krachaidum, or Thai Ginseng) is a traditional Thai medicinal plant with small-trial clinical evidence for athletic performance and erectile function. The active compounds are methoxyflavones — polymethoxyflavones found in this plant that inhibit phosphodiesterase-5 (a vasodilation-related enzyme), activate AMPK, and have anti-inflammatory effects in laboratory studies. Clinical trials show improvements in exercise capacity, fat oxidation, grip strength in older adults, and modest improvements in erectile function. Also being investigated for cognitive support and metabolic health. The honest framing: an evidence-supported botanical with multiple plausible mechanisms; effects on exercise performance and erectile function are modest but real, and the safety profile is good for an emerging botanical with several decades of traditional use.

Studied Dose Human trials used 25 to 90 mg/day in elderly fitness, 180 mg/day in soccer players, 360 mg/day in adolescent athletes, and 100 mg/day in the erectile-function pilot.
Active Compound 5,7-dimethoxyflavone (5,7-DMF, primary marker), 3,5,7-trimethoxyflavone, 5-hydroxy-3,7-dimethoxyflavone, polymethoxyflavones; standardized to 5% 5,7-DMF.

Benefits

Exercise capacity and physical performance

Clinical trials show improvements in exercise capacity, time to exhaustion, and grip strength with Kaempferia parviflora supplementation in healthy and older adults. Effects build over weeks of consistent use combined with training.

Erectile function improvement

Clinical trials in men with mild erectile dysfunction show modest improvements in erectile function with Kaempferia parviflora. Laboratory work points to phosphodiesterase-5 inhibition as one proposed mechanism. The human evidence is a single small open-label pilot with no placebo group, so the size of any real effect is uncertain.

Fat oxidation and energy metabolism

Methoxyflavones activate AMPK and support fat oxidation, particularly during exercise. Clinical trials show modest improvements in body composition over weeks of supplementation combined with physical activity.

Grip strength in older adults

Trials in older adults show improvements in grip strength — a marker of overall muscle function and predictor of longevity — with Kaempferia parviflora supplementation over months of use.

PDE5 inhibition mechanism

In laboratory assays methoxyflavones inhibit phosphodiesterase-5, which raises cGMP and can promote vasodilation. This is a proposed mechanism from test-tube data, not a demonstrated clinical effect, and it should not be read as equivalent to a prescription PDE-5 medication.

Cardiovascular effects not demonstrated in humans

No human trial on this page measured a cardiovascular outcome such as blood pressure, endothelial function, or lipids. Any cardiovascular benefit is speculative and rests on mechanism alone.

AMPK activation for metabolic effects

Methoxyflavones activate AMPK, an energy-sensing enzyme, in cell and animal studies. This is a plausible mechanism for the metabolic and exercise signals, but it has not been shown to reproduce the clinical effects of any prescription drug.

Generally well-tolerated

Clinical trials show good tolerability with side effects no more frequent than placebo. Decades of traditional Thai use support a reasonable safety profile, though long-term high-dose safety data is still emerging.

Mechanism of action

1

PDE-5 inhibition (laboratory mechanism)

In laboratory assays polymethoxyflavones inhibit phosphodiesterase-5. This is the proposed basis for the sexual-function signal, but in people it has only been tested in one small uncontrolled study. Because the enzyme is also the target of prescription ED drugs, combining the two could in theory add up, so caution is warranted.

2

Cellular energy metabolism enhancement

Increased cellular energy metabolism contributes to improved physical fitness performance and muscular endurance. Mechanism distinct from caffeine-style stimulant pathways.

3

Brown adipose tissue activation and thermogenesis

BAT activation evidence supports a thermogenic mechanism distinct from caffeine-based thermogenics. Methodological quality of the underlying trial was limited (Jadad 1) — interesting mechanism awaiting better-designed human trials.

4

Polymethoxyflavone bioactivity (5,7-DMF)

Methoxylation distinguishes from typical flavonoids — enhances oral bioavailability, membrane permeability, and diverse pharmacological activities. 12 different methoxyflavones identified. 5,7-DMF is the primary bioavailability marker.

5

Anti-inflammatory NF-κB pathway

NF-κB pathway suppression contributes anti-inflammatory effects — relevant to the osteoarthritis indication in the literature.

6

Testosterone biosynthesis support

Mouse testis-derived cell evidence — preclinical testosterone biosynthesis support. Mechanistic basis for the men's-health positioning, though human testosterone outcomes have not been demonstrated.

7

Adipocyte hypertrophy suppression

Adipocyte hypertrophy suppression supports the anti-obesity research signal. Preclinical mechanism.

Clinical trials

1
K. parviflora ED Pilot
PubMed

Clinical evidence on Black Ginger (Kaempferia parviflora / Krachaidum / Thai Ginseng) for the indications and outcomes described.

13 men

Stein RA et al. 2018 (J Integr Med 16(4):249-254). Open-label, uncontrolled pilot with no placebo group: 13 healthy men aged 50 to 68 with self-reported mild ED took 100 mg/day of a K. parviflora ethanol extract (KaempMax, from the study sponsor Life Extension) for 30 days. IIEF scores improved and about 62 percent reported better erections, but without a control group the true effect size is unknown.

2
Systematic Review of 7 K. parviflora Trials (review, not a single trial)
PubMed

Clinical evidence on Black Ginger (Kaempferia parviflora / Krachaidum / Thai Ginseng) for the indications and outcomes described.

Clinical population described in trial publication.

Saokaew S et al. 2017 (J Evid Based Complementary Altern Med 22(3):413-428). Systematic review of 7 small clinical trials. The authors concluded the evidence is positive but inconclusive because the studies were small: increased hand-grip strength rested on 2 studies and enhanced sexual response on 1. No serious adverse events were reported.

3
K. parviflora Physical Fitness RCT (Soccer Players)
PubMed

Clinical evidence on Black Ginger (Kaempferia parviflora / Krachaidum / Thai Ginseng) for the indications and outcomes described.

Clinical population described in trial publication.

Promthep K et al. 2015 (Med Sci Monit Basic Res 21:100-8). Randomized, double-blind, placebo-controlled trial in 60 soccer players given 180 mg/day K. parviflora extract or placebo for 12 weeks. Hand-grip strength improved, but sprint speed, back-and-leg strength, flexibility, and cardiorespiratory fitness did not differ from placebo.

Side effects and drug interactions

Common Potential side effects

Generally well-tolerated at typical doses.
Mild GI upset (rare).
Theoretical mild stimulant effects (energy ingredient).
Pregnancy/lactation: avoid (limited data + theoretical hormonal effects).
Allergic reactions in ginger family (Zingiberaceae) sensitive individuals (rare).
Long-term safety: extensive Thai traditional use + systematic review evidence supportive at typical doses.
High doses concerning — limited safety data above 200 mg/day.

Important Drug interactions

PDE-5 inhibitors (sildenafil/Viagra, tadalafil/Cialis): theoretical additive PDE-5 inhibition — caution; consult physician before combining.
Antihypertensives: theoretical mild additive vasodilatory effects.
Anticoagulants: theoretical mild antiplatelet effects.
Diabetes medications: theoretical glucose metabolism effects.
Most medications: well-tolerated at typical doses.
Stimulants: caution due to mild thermogenic/energy effects.

Frequently asked questions about Black Ginger (Kaempferia parviflora / Krachaidum / Thai Ginseng)

What is Kaempferia parviflora (black ginger) used for?

Kaempferia parviflora, or black ginger (Thai black ginger), is a rhizome used in Thai tradition for energy, stamina, male vitality, and athletic and metabolic support. It contains methoxyflavones as active compounds.

What is black ginger good for?

It is studied for exercise performance and endurance, male sexual function, and metabolic support, with some promising small human studies. It is popular in energy and vitality formulas.

How much black ginger should I take?

Studies use standardized extracts, often around 25 to 100 mg per day; follow product labeling. It is taken as an extract rather than as a culinary spice.

Is Kaempferia parviflora safe?

It is generally reported as well tolerated in studies. As with many vitality herbs, long-term human data is limited, so use as directed, and those on medication or with medical conditions should check with a doctor.

What is Black Ginger?

Kaempferia parviflora (also called Black Ginger, Krachaidum, or Thai Ginseng) is a traditional Thai medicinal plant with small-trial clinical evidence for athletic performance and erectile function.

What is Black Ginger used for?

Black Ginger is researched primarily for Athletic Performance, Men's Health, and Weight Management. Clinical trials show improvements in exercise capacity, time to exhaustion, and grip strength with Kaempferia parviflora supplementation in healthy and older adults. Effects build over weeks of consistent use combined with training.

What is the recommended dosage of Black Ginger?

The clinically studied dose is Human trials used 25 to 90 mg/day in elderly fitness, 180 mg/day in soccer players, 360 mg/day in adolescent athletes, and 100 mg/day in the erectile-function pilot. Always follow the product label and check with a healthcare provider for personal advice.

Is Black Ginger safe, and does it have side effects?

For most healthy adults, Black Ginger is well tolerated at studied doses. Reported effects can include: Generally well-tolerated at typical doses. Mild GI upset (rare). It may also interact with some medications. Black Ginger is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Black Ginger interact with any medications?

Possible interactions include: PDE-5 inhibitors (sildenafil/Viagra, tadalafil/Cialis): theoretical additive PDE-5 inhibition — caution; consult physician before combining. Antihypertensives: theoretical mild additive vasodilatory effects. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Black Ginger?

NutraSmarts rates the evidence for Black Ginger as Limited (2 out of 5). It is backed by 3 clinical trials and 9 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(9 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Na Takuathung M, Klinjan P, Koonrungsesomboon N. A systematic review and meta-analysis of animal and human studies demonstrates the beneficial effects of Kaempferia parviflora on metabolic syndrome and erectile dysfunction. Nutr Res. 2024;122:80-91. doi: 10.1016/j.nutres.2023.12.001.PubMedUsed to support: Metabolic/erectile synthesis (mostly animal)
  2. Sripanidkulchai B, Promthep K, Tuntiyasawasdikul S, Tabboon P, Areemit R. Supplementation of Kaempferia parviflora Extract Enhances Physical Fitness and Modulates Parameters of Heart Rate Variability in Adolescent Student-Athletes: A Randomized, Double-Blind, Placebo-Controlled Clinical Study. J Diet Suppl. 2022;19(2):149-167. doi: 10.1080/19390211.2020.1852356.PubMedUsed to support: Randomized controlled trial in which Kaempferia parviflora supplementation enhanced physical fitness and modulated metabolic parameters. Supports the athletic-performance use.
  3. Promthep K, Eungpinichpong W, Sripanidkulchai B, Chatchawan U. Effect of Kaempferia parviflora Extract on Physical Fitness of Soccer Players: A Randomized Double-Blind Placebo-Controlled Trial. Med Sci Monit Basic Res. 2015;21:100-8. doi: 10.12659/MSMBR.894301.PubMedUsed to support: Randomized double-blind trial reporting improved physical fitness in soccer players taking black ginger. Adds controlled support for the performance use.
  4. Jacob J, Gopi S, Divya C. A Randomized Single Dose Parallel Study on Enhancement of Nitric Oxide in Serum and Saliva with the Use of Natural Sports Supplement in Healthy Adults. J Diet Suppl. 2018;15(2):161-172. doi: 10.1080/19390211.2017.1331944.PubMedUsed to support: Nitric oxide mechanism (blend, not black ginger alone)
  5. Wattanathorn J, Muchimapura S, Tong-Un T, Saenghong N, Thukhum-Mee W, Sripanidkulchai B. Positive Modulation Effect of 8-Week Consumption of Kaempferia parviflora on Health-Related Physical Fitness and Oxidative Status in Healthy Elderly Volunteers. Evid Based Complement Alternat Med. 2012;2012:732816. doi: 10.1155/2012/732816.PubMedUsed to support: Study of 8 weeks of black ginger reporting positive modulation of health-related physical fitness. Supports the athletic use.
  6. Wasuntarawat C, Pengnet S, Walaikavinan N, Kamkaew N, Bualoang T, Toskulkao C, McConell G. No effect of acute ingestion of Thai ginseng (Kaempferia parviflora) on sprint and endurance exercise performance in humans. J Sports Sci. 2010;28(11):1243-50. doi: 10.1080/02640414.2010.506221.PubMedUsed to support: Randomized trial that found no effect of a single dose of black ginger on sprint or endurance exercise. Included for balance: benefits appear with longer supplementation, not acute dosing.
  7. Saokaew S, Wilairat P, Raktanyakan P, Dilokthornsakul P, Dhippayom T, Kongkaew C, Sruamsiri R, Chuthaputti A, Chaiyakunapruk N. Clinical Effects of Krachaidum (Kaempferia parviflora): A Systematic Review. J Evid Based Complementary Altern Med. 2017;22(3):413-428. doi: 10.1177/2156587216669628.PubMedUsed to support: Overall evidence synthesis
  8. Stein RA, Schmid K, Bolivar J, Swick AG, Joyal SV, Hirsh SP. Kaempferia parviflora ethanol extract improves self-assessed sexual health in men: a pilot study. J Integr Med. 2018;16(4):249-254. doi: 10.1016/j.joim.2018.05.005.PubMedUsed to support: Men's Health / erectile function
  9. Yoshino S, Tagawa T, Awa R, Ogasawara J, Kuwahara H, Fukuhara I. Polymethoxyflavone purified from Kaempferia parviflora reduces visceral fat in Japanese overweight individuals: a randomised, double-blind, placebo-controlled study. Food Funct. 2021;12(4):1603-1613. doi: 10.1039/d0fo01217c.PubMedUsed to support: Weight Management