IngredientsBlack ginger, known scientifically as Kaempferia parviflora Wall. ex Baker, is a herbaceous plant belonging to the family Zingiberaceae and is commonly known by its Thai name "krachai dum." It is a rhizomatous perennial plant distinguished from common ginger by its dark purple, almost black rhizome. The plant is found in the upper northeastern regions of Thailand, and it is called "black ginger" because of the intense purple-black color and similar shape of its roots to ginger.
Formally designated Kaempferia parviflora Wall. ex Baker (KP), it is the most scientifically studied species in its genus and has gained significant attention in the past two decades as a revitalizer. It is also referred to in English as black galingale and in Thailand as Thai ginseng, reflecting its reputation as a general tonic. A food crop and herbal plant native to Southeast Asia, it has been used for centuries in traditional Asian medicine for its numerous health benefits, particularly antioxidant and anti-inflammatory activities.
It is an aromatic plant native to Thailand, notable for its richness in methoxyflavones—distinct compounds possessing potent pharmacological properties. Taxonomically designated Kaempferia parviflora Wallich. ex Baker, it is originally found in the North and Northeast of Thailand. The rhizome's distinctive dark coloration arises from high concentrations of polymethoxyflavones (PMFs), a group of bioactive compounds responsible for many of the plant's unique properties.
The tissues of Kaempferia parviflora contain essential oil glands distributed throughout the rhizome, leaves, and stem. The leaves are lanceolate to oblong, arranged alternately along the pseudostem. Ginger flowers are zygomorphic (bilaterally symmetrical) and typically borne in terminal or basal inflorescences with colourful bracts. The primary commercial and medicinal part is the rhizome, which is the underground storage organ of the plant.
K. parviflora has been used as a herbal product in a variety of preparations, including fresh or dried rhizomes, dried powder in tea bags, and wine. It has also been made into a variety of dietary supplements, including medicinal liquor or liquor plus honey, pills (powdered rhizome with honey), capsules, and tablets. In modern commercial settings, the rhizome is typically processed into standardized extracts — a powdered black ginger extract standardized as a food ingredient to contain not less than 2.5% of 5,7-dimethoxyflavone and 10% of total PMFs.
Black ginger, the rhizome of Kaempferia parviflora (Zingiberaceae), has traditionally been used as a food and folk medicine for more than 1,000 years in Thailand. Traditionally, the rhizome of KP has been utilized to promote blood flow and increase vitality in Thailand and Laos, where it is indigenous.
In Thai traditional medicine, the rhizome was utilized for centuries to treat a variety of ailments through decoctions prepared by boiling the rhizome. These preparations were commonly employed to alleviate allergies, asthma, gout, diarrhea, peptic ulcers, and colic, reflecting its role as a versatile remedy in folk healing practices.
It is popular as a health-promoting herb and was traditionally used as a folk medicine for managing a variety of diseases, including inflammation, ulcers, gout, colic disorder, abscesses, allergy, and osteoarthritis. KP is known as black ginger, Krachaidum, or Thai ginseng, and its rhizome and leaves have documented traditional uses relating to antiallergenic, antimutagenic, anticholinesterase, anti-peptic ulcer, and cardioprotective activities.
Thai ginseng, Kaempferia parviflora, is widely believed among the Mong hill tribe to reduce perceived effort and improve physical work capacity, and it is consumed before daily work. Traditionally, K. parviflora was used for gastrointestinal disorders, allergies, as a sexual stimulant, and for body nourishment.
Reputed for its aphrodisiac effect, rhizomes of Kaempferia parviflora have been used as traditional medicine for various medicinal purposes including as a tonic for rectifying male erectile dysfunction. In traditional medicine, rhizomes are brought to boil or soaked with alcohol and used as an elixir to improve sexual performance.
Kaempferia parviflora has been used in traditional Thai medicine to cure gastrointestinal disorders since ancient times. Its traditional use as a health tonic and energy enhancer led to it being called "Thai ginseng."
Polymethoxyflavones and anthocyanins are the main phenolic compounds in black ginger. Modern analysis has revealed that black ginger's effects come primarily from its rich content of polymethoxyflavones (PMFs). The phytochemical constituents of black ginger include phenolic compounds, carotenoids, vitamins, fatty acids, phytosterols, and essential oils.
The most extensively characterized PMFs identified in K. parviflora rhizomes include:
5,7-Dimethoxyflavone (DMF) is the primary bioactive phytochemical with antioxidant and anti-inflammatory activities and is used as a quality control marker, with KP powder produced for food ingredients containing at least 2.5%.
The essential oils of K. parviflora are complex mixtures of terpenoids (such as zingiberene, bisabolene, and cineole) and phenylpropanoids. Terpenoids, flavonoids, phenolics, and essential oils possessing biological properties have been reported to date from the plants of the genus Kaempferia.
The pharmacological activities of black ginger extract (KPE) and its constituent PMFs are mediated through several documented molecular pathways:
Polymethoxyflavones (PMFs) in black ginger extract have been reported to increase energy production by activating AMP-activated protein kinase (AMPK) in C2C12 myoblasts. Treatment with KPE and PMFs fraction induced the activation of AMP-activated protein kinase (AMPK) signaling; pretreatment with an AMPK signaling inhibitor significantly attenuated KPE- and PMFs fraction-induced suppression of lipid formation, demonstrating that KPE and PMFs fraction inhibit lipid formation by inhibiting the differentiation of undifferentiated mesenchymal stem cells into adipocyte lineages via AMPK signaling.
In a screening study of forty-one plant extracts for PDE5 inhibitory activity, the plants were selected by their ethnopharmacology. Twenty-one plants included in the screen are used as sexual performance enhancers in the traditional medicines of Northern Thailand. In this screening, two traditional sexual performance enhancer plants — Caesalpinia sappan and Kaempferia parviflora — showed moderate effects on PDE5 (60–70% inhibitions). The IC50 values were in the range of 10–50 μg/ml, which was significantly higher than that of sildenafil.
Studies on isolated rat aortic rings revealed that 5,7-dimethoxyflavone (DMF) causes endothelium-dependent relaxation and vasodilation, effects partly mediated by the NO-cGMP and cyclooxygenase pathways. In vitro studies noted increased mRNA and protein expression of endothelial nitric oxide synthase (eNOS), which is present in the endothelium of the penile vasculature and sinusoidal endothelium within the corpora cavernosa, and it was concluded that this may result in an improvement in endothelial function. Experiments on rats suggested this plant extract may enhance copulatory behavior partly via the induction of hypothalamic dopaminergic D1 receptor expression.
The expression of iNOS (inducible nitric oxide synthase) induced by lipopolysaccharide was drastically decreased depending on the concentration of K. parviflora extracts; COX-2 expression was also reduced at 20 μg/mL of K. parviflora extract. The anti-inflammatory effect on the NF-κB signaling pathway was also documented: K. parviflora markedly downregulated the expression of phosphorylated inhibitor kappa B-alpha (IκBα) and NF-κB, suggesting that the anti-inflammatory activity of K. parviflora in LPS-stimulated macrophage cells may be due to the suppression of the NF-κB signaling pathway.
KPE inhibited adipogenesis by decreasing key adipogenic transcription factors and enzymes (CCAAT/enhancer binding protein α, PPARγ, SREBP-1c, acetyl-CoA carboxylase 1, ATP-citrate lyase, and fatty acid synthase mRNA expression) and improved lipolysis by increasing carnitine palmitoyl transferase 1 and hormone-sensitive lipase mRNA expression, suggesting that KPE inhibited obesity by regulating several pathways involved in decreasing adipogenesis and enhancing lipolysis.
At the muscle level, IL-6 and TNF-α mRNA expression levels were decreased in the soleus muscle after KPE treatment, whereas PGC-1α and glycogen synthase mRNA expression levels, mitochondrial number, and glycogen content were increased.
The administration of 100 mg/day of KPE extract appears to increase energy expenditure in brown adipose tissue (BAT)-positive subjects, and the activation of brown adipocytes is detectable via FDG-PET after exposure to cold. Yoshino et al. reported that oxygen consumption by mice fed with black ginger was significantly increased, indicating enhanced energy metabolism activated by brown adipose tissue.
The beneficial effects of KP and its methoxyflavones are thought to be associated with increased mitochondrial functions and activated cGMP-NO signaling pathways. However, the underlying molecular mechanisms are still under investigation, and the clinical applications of KP and its methoxyflavones may be limited due to their low bioavailability.
This is the area with the most clinical (human) evidence for K. parviflora.
Elderly subjects (RCT): A randomized, double-blind, placebo-controlled trial published in the Journal of the International Society of Sports Nutrition (2018) investigated the effects of a KPE on physical performance in healthy elderly subjects. The study involved 60 participants who received either 100 mg of KPE daily or a placebo for 8 weeks. The KPE group experienced significant improvements in hand grip strength, 30-second chair stand test (a measure of lower body strength), and 6-minute walk distance (a measure of endurance) compared to the placebo group.
Soccer players (RCT): Sixty soccer players who routinely trained at a sports school participated in a double-blind placebo-controlled trial and were randomly allocated to the treatment group or the placebo group. Participants in both groups were given either 180 mg of Kaempferia parviflora extract in capsules or a placebo once daily for 12 weeks. The study showed that after treatment with Kaempferia parviflora, the right-hand grip strength was significantly increased at weeks 4, 8, and 12; left-hand grip strength was significantly increased at week 8; however, the back-and-leg strength, the 40-yard technical test, sit-and-reach, and other measures showed no significant differences. Taking Kaempferia parviflora supplements for 12 weeks may significantly enhance some physical fitness components in soccer players, though not all tested parameters were affected.
Functional drink / healthy adults (RCT): A 12-week, 3-arm randomized, double-blind, placebo-controlled, parallel group study was conducted at the Faculty of Medicine, Khon Kaen University, to test whether K. parviflora could be used as a functional ingredient for enhancing physical fitness of healthy adults. A total of 87 male and female healthy adult volunteers aged 19–60 years participated. This study was the first to demonstrate that a functional drink containing K. parviflora extract can improve cardiorespiratory fitness and some physical performance, with the possible underlying mechanism partly associated with the reduction of oxidative stress and serum lactate. Limitations included a limited number of subjects and indirect assessment of VO2 max due to COVID-19 restrictions.
Acute ingestion (null result): A study on the effects of K. parviflora on repeated bouts of sprint exercise and endurance exercise to exhaustion was conducted using a randomized, double-blind, crossover design. Ninety minutes after consumption of K. parviflora or a starch placebo, participants in study 1 (n=19) completed three consecutive maximum 30-second sprint cycling Wingate tests, while participants in study 2 (n=16) performed submaximal cycling exercise to exhaustion. Peak and mean power output decreased with successive Wingate tests, while percent fatigue and blood lactate concentration increased after the third Wingate test (P<0.05), with no beneficial effect from the single acute dose. This study illustrates that the ergogenic effects of KPE may require longer-duration (multi-week) supplementation rather than acute single-dose administration.
Preclinical (animal) support: In an in vitro test using C2C12 myoblasts, several PMF including 5,7-dimethoxyflavone improved muscular metabolism and suppressed muscular inflammatory responses. Physical fitness performance and muscular endurance were superior in mice orally administered KPE (45 mg/kg/day) for 4 weeks compared to control mice. KPE enhanced physical fitness, including grip strength, leg muscle strength, balance, endurance, and locomotor activity in athletes, the elderly, and healthy individuals.
Overall strength of evidence: Multiple small-to-medium sized RCTs in humans suggest benefits for muscular strength and aerobic capacity with multi-week supplementation, particularly in elderly populations. Results are mixed for some performance measures. Larger, independent trials are needed. The preclinical mechanistic base is strong.
Human RCT (abdominal fat): As no clinical trials had previously evaluated the anti-obesity effects of KPE in humans, a 12-week, single-center, randomized, double-blind, placebo-controlled clinical trial was conducted. Seventy-six subjects (males and females, aged 20 to <65 years) with a BMI ≥24 and <30 kg/m² were randomly assigned into two groups; the subjects ingested one capsule of placebo or active KPE (containing 150 mg of KPE) once daily for 12 weeks. Subgroup analyses demonstrated a significant reduction in abdominal fat area and triglyceride levels in healthy subjects compared with the placebo group after 12 weeks. Neither group exhibited adverse events related to the test foods or clinically relevant abnormal changes in physical, biochemical, or hematologic parameters, or in urinalysis results. The conclusion was that daily ingestion of KPE safely reduces body fat, particularly abdominal fat, in Japanese overweight and preobese subjects.
Systematic review and meta-analysis: The in vivo effects of KPE were evaluated through a systematic review and meta-analysis, demonstrating significant improvements in metabolic syndrome, erectile dysfunction, fasting blood glucose levels, sexual function, and physical performance, supporting the potential health benefits of the KPE. A recent meta-analysis including 57 articles (both clinical and preclinical studies) focusing on metabolic syndrome and erectile dysfunction suggested improvements in blood glucose, physical, and exercise performance, but not other metabolic or reproductive function parameters, following K. parviflora administration. The variation in effects was attributed to high heterogeneity of intervention including formulation, dose, duration, and study population.
Preclinical (animal) evidence: KPE decreased body weight, body fat mass, adipose tissue weight, adipocyte size, and serum levels of glucose, triglycerides, cholesterol, insulin, and leptin in high-fat diet-induced obese mice. KPE and some PMF have been reported to exert their anti-obesity effects by increasing energy metabolism, regulating lipid metabolism, and activating lipolysis in white adipose tissue through the inhibition of pancreatic lipase.
Overall strength of evidence: Preclinical data are robust. Human data are preliminary but positive, with one RCT showing reduced abdominal fat. The high heterogeneity noted in the meta-analysis limits firm conclusions. Independent large-scale RCTs are warranted.
KP's rhizome and leaves have documented antiallergenic, antimutagenic, anticholinesterase, anti-peptic ulcer, and cardioprotective activities, and the plant has been prominently associated with sexual performance enhancement in traditional practice.
Mechanism of action (in vitro and animal): Forty-one plant extracts and eight 7-methoxyflavones from Kaempferia parviflora Wall. ex Baker were screened for PDE5 and PDE6 inhibitory activities using the two-step radioactive assay. The PDE5 inhibitor sildenafil is currently used for erectile dysfunction as it increases the level of cGMP, which induces vascular smooth muscle relaxation, vasodilation, and increases blood flow to penile tissue. The methoxyflavones of KP were found to act through this same pathway, albeit with lower affinity than pharmaceutical PDE5 inhibitors. PMF demonstrated a relaxing effect on isolated human corpus cavernosum tissue via calcium mobilization and has also been identified as an important mediator of PDE5/PDE6 inhibition and vasorelaxation, suggesting potential benefit in the treatment of erectile dysfunction.
Clinical study (pilot): In a pilot study in 2018, 14 elderly adult men with erectile dysfunction received Kaempferia parviflora ethanol extract for 30 days; 13 males reported statistically significant improvements in erectile function and enhanced sex satisfaction on a self-assessed questionnaire. This was a small, open-label study and should be interpreted cautiously.
Overall strength of evidence: Predominantly preclinical and mechanistic. The in vitro and animal data support biologically plausible PDE5-inhibitory and vasodilatory mechanisms. Human clinical evidence consists of a single small pilot study. Larger, controlled human trials are needed to substantiate clinical efficacy.
K. parviflora extract significantly suppressed the production of nitric oxide in murine macrophage-like cell line (RAW 264.7) cells in a concentration-dependent manner; at 20 μg/mL, the NO level was decreased to that observed in the control. These results showed that K. parviflora extract inhibited the expression of iNOS, which subsequently reduced the production of NO, a key mediator of the inflammatory response. The LPS-induced elevated level of the cytokine TNF-α was also significantly reduced by K. parviflora extract.
The active chemical constituents of the ethanol extract of K. parviflora — specifically 5,7-dimethoxyflavone, trimethylapigenin, and tetramethylluteolin — bear anti-inflammatory activity and are responsible for inhibition of nitric oxide synthase expression in RAW 264.7 cells.
Overall strength of evidence: The anti-inflammatory evidence is robust at the in vitro and preclinical levels, with well-characterized molecular targets (NF-κB, iNOS, COX-2, TNF-α). Human clinical trials specifically targeting inflammatory outcomes are lacking.
KP exhibits a diverse range of pharmacological activities, including anti-inflammatory, anti-allergic, antioxidant, and neuroprotective properties. Previous studies have demonstrated KP's potential in addressing cognitive impairments and neurodegenerative diseases.
K. parviflora possesses health-promoting benefits including anti-oxidative stress and anti-inflammation in vitro and in vivo with a high level of safety; however, the role of KP in suppressing amyloid-beta (Aβ)-mediated neuroinflammation and neuronal differentiation had not previously been thoroughly investigated. Neuroprotective effects of KP extract against Aβ42 have been examined in both monoculture and co-culture systems of mouse neuroectodermal (NE-4C) stem cells and BV-2 microglia cells.
Potentially useful in the treatment of neurodegenerative disorders, Kaempferia parviflora has been shown to possess a wide spectrum of neuropharmacological activities and neuroprotective effects in vivo and in vitro. Studies examined whether K. parviflora ethanolic extract could influence the levels of neurotransmitters and the whole proteomic profile in the hippocampus of Sprague Dawley rats.
Overall strength of evidence: Neuroprotective evidence is entirely preclinical (in vitro and animal models). There are no published human clinical trials specifically investigating cognitive outcomes from KPE. This remains a promising but exploratory area of research.
K. parviflora can potentially be developed as an anticancer and antimetastatic agent. It has numerous pharmacological activities including neuroprotective, antibiotic, aphrodisiac, anti-obesity, antidiabetic, anti-inflammation, and anticancer actions. KP, in the form of crude extract and its pure compound, has a cytotoxic effect on several cancer cell models.
5-Hydroxy-7-methoxyflavone and 5,7-dimethoxyflavone obtained from K. parviflora have been identified as potent inhibitors of HIV-1 protease activity.
Overall strength of evidence: All anticancer evidence is currently in vitro (cell lines) and preclinical. No human clinical trials on cancer outcomes have been reported. This area is exploratory only.
K. parviflora has demonstrated antioxidant, anti-inflammatory, antiobesity, anticancer, vascular relaxation, and antimicrobial effects in preclinical research. Pharmacological studies have documented vascular relaxation and cardioprotective activity among the claimed benefits of KP and its main effective methoxyflavones. The vasorelaxant mechanism proceeds primarily through the NO-cGMP pathway and eNOS upregulation, as described above under mechanisms. Human clinical evidence specifically for cardiovascular endpoints is not yet available from published controlled trials.
K. parviflora has been used in traditional Thai medicine to cure gastrointestinal disorders since ancient times. Its rhizomes are used to treat a variety of gastrointestinal disorders and improve blood flow as traditional treatments for inflammatory and allergic disorders. At the preclinical level, an ethyl acetate extract of K. parviflora has been studied for its inhibition of Helicobacter pylori-associated mammalian cell inflammation, regulating proinflammatory cytokine expression and leukocyte chemotaxis. Human clinical evidence for gastrointestinal applications beyond traditional use is lacking.
K. parviflora, also known as black ginger or "krachai dum" in Thai, is a herbaceous plant belonging to the Zingiberaceae family. It has been traditionally used as a health-promoting alternative medicine with anti-inflammatory, anti-allergic, anticholinesterase, adaptogenic, and anti-obesity effects. K. parviflora contains several flavonoids, including 5,7-dimethoxyflavone, 5-hydroxy-3,7,4′-trimethoxyflavone, and 5-hydroxy-3,7-dimethoxyflavone. The extracts of this plant have shown efficacies against several disorders, including metabolic, sexual, and cognitive disorders, as well as cancer. Research specifically examining sebostatic, anti-inflammatory, and anti-Propionibacterium acnes activity of KPE has been published (PMC6274695), though this remains in vitro data at this stage.
The following dosages appear in peer-reviewed clinical studies. These are reported descriptively as found in the sources and do not represent a therapeutic recommendation.
Despite promising bioactivity, the development of KP as a therapeutic agent remains insufficiently explored, with existing research yet to be fully integrated. Optimal dosing parameters in humans have not yet been formally established.
A previous acute toxicity study in mice reported a mean lethal dose of KP rhizomes of >13.3 g/kg; through an acute toxicity study, the mean lethal dose of KP extract was determined to be >2000 mg/kg. Toxicity analyses of 6-month dietary intake of 500 mg/kg body weight per day of KP ethanolic extract in rats indicated no adverse effects. The results of sub-chronic evaluation revealed no genotoxicity or sub-chronic toxicity related to polymethoxyflavone-standardized KP extract treatment. The statistically significant changes in platelet count and organ weight observed in some cases were not considered toxicologically relevant, as these changes were non-severe and parameters remained within historical control ranges.
KP extract exhibited no genotoxicity. The no-observed-adverse-effect-level (NOAEL) of the extract was >249 mg/kg. The results indicate that Kaempferia parviflora extract has a high degree of safety.
In a chronic toxicity study, three treatment groups were orally administered K. parviflora extract at doses of 5, 50, and 500 mg/kg/day for six months respectively (equivalent to 1, 10, and 100 times the human use dose). The results showed that male rats receiving the extract at a dose of 500 mg/kg had significantly lower body weight than control groups, while alterations of a few hematological parameters in the highest dose-treated groups were within the normal range.
A previous study examining daily administration of KP extract for 6 months in rats reported no toxicological effects. Other studies reported that daily intake of KP extract for 12 weeks had no adverse effects on blood chemistry parameters.
In the 12-week human RCT for abdominal fat, neither the KPE nor the placebo group exhibited adverse events related to the test foods, or clinically relevant abnormal changes in physical, biochemical, or hematologic parameters, urinalysis results, or medical interview findings.
No adverse events were reported even when Krachaidum was used at 1.35 g/day.
KP extract has attracted attention as a dietary supplement; however, there is little information regarding food-drug interactions (FDIs). Investigations were conducted to clarify the FDI of KP extract via inhibition of cytochrome P450 3A (CYP3A), a typical drug-metabolizing enzyme. The inhibitory effects of KP extract and its main ingredients, 5,7-dimethoxyflavone and 3,5,7,3′,4′-pentamethoxyflavone, on CYP3A-mediated midazolam 1′-hydroxylation activity were investigated in human liver microsomes.
KP extract competitively inhibited CYP3A-mediated midazolam metabolism with an inhibition constant value of 78.14 μg/ml, which was lower than the estimated concentration in the small intestine after ingestion. Furthermore, KP extract, 5,7-DMF, and 3,5,7,3′,4′-PMF inhibited the activity in a time-, NADPH-, and concentration-dependent manner.
In a separate murine study, in the group administered 5,7-DMF, the area under the curve (AUC) of midazolam increased by 130% and its biological half-life was extended by approximately 100 min compared to the control group. It is suggested that continued ingestion of 5,7-DMF decreases the expression of CYP3As in the liver, consequently increasing the blood concentrations of drugs metabolized by CYP 3As.
CYP3A4 is the enzyme responsible for metabolizing a large proportion of clinically important pharmaceutical drugs. This in vitro and animal-model evidence of CYP3A inhibition by KPE constituents indicates a potential interaction risk with drugs that are CYP3A substrates (including many immunosuppressants, benzodiazepines, statins, calcium channel blockers, and antiretrovirals), though direct human pharmacokinetic interaction studies have not yet been published.
A randomized, double-blind, placebo-controlled trial specifically evaluating the safety of daily consumption of Kaempferia parviflora extract (KPFORCE) was published in the Journal of Medicinal Food (2019). An additional randomized, double-blind, placebo-controlled crossover clinical study evaluating the safety and efficacy of Kaempferia parviflora extract (SIRTMAX®) in humans was published in Japanese Pharmacology and Therapeutics (2015).
Published peer-reviewed safety data in pregnant women, lactating women, children, or individuals with severe hepatic or renal impairment are not available in the reviewed literature. The interaction potential with anticoagulants, PDE5 inhibitor drugs (e.g., sildenafil), and cardiovascular medications has not been formally studied in humans, despite mechanistic overlap.
Health conditions that Black ginger may help support.
Body systems that Black ginger may help support.
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