Green Botanica · Plant Guide
Kaempferia parviflora
Krachai dam · กระชายดำ · Thai black ginger
Black ginger is not true ginger but a small relative from the same family. Its knobbly brown rhizomes hide a deep purple heart. In the hills of northern Thailand it has long been a household tonic, steeped in honey or local liquor. Dried and milled, it gives an earthy, gently bitter, purple-brown powder that is used in small amounts.
Meet the plant
Black ginger is a small perennial of the ginger family, Zingiberaceae, only 20–30 cm tall. Its broad, oval leaves often have reddish edges, and its small white flowers have a pale violet lip.
Underground it forms knobbly clumps of rhizomes, brown outside and light to deep purple inside. The colour comes from anthocyanins, the pigments that also colour blueberries. Despite its name, it is not true ginger (Zingiber officinale): it has none of ginger’s heat and carries its own compounds, the methoxyflavones.
Fresh slices are steeped in white rice liquor and taken by the small glass, a classic Thai home preparation.
Dried rhizome is kept in honey, or the powder is rolled with honey into small pills.
Thin dried slices are simmered or steeped in hot water for a dark, earthy drink.
In Phu Ruea, Loei, a community product combines black ginger and honey for stirring into coffee.
The dried rhizome, finely milled and stirred in small amounts into coffee, milk or yoghurt.
Teas, drinks and capsules in Thailand; in Japan, a popular ingredient in functional foods.
The story
In a few decades, a household tonic of the northern hills has become one of Thailand’s best-studied plants.
Hmong communities in Thailand’s northern hills have kept black ginger as a household tonic for over a hundred years, reportedly also to walk further in the mountains.
Under the One Tambon One Product scheme, black ginger teas, capsules and liquors from Loei and Phitsanulok became a village success story.
Within one season, trader prices fell from 638 baht per kilo at the peak to 92 baht by December. A farmer survey that year found average sale prices below the cost of growing.
Thai and Japanese researchers start testing black ginger extracts in people. In Japan it becomes a popular ingredient of “Foods with Function Claims”, fifth by new notifications in 2024.
The Thai Herbal Pharmacopoeia gives the dried rhizome its own monograph.
Thailand’s Ministry of Public Health names black ginger one of three national “Herbs of the Year”.
Black ginger is a plant of the hills, growing best in cool, partly shaded uplands at around 500–700 m. Thailand’s main growing area lies where Loei and Phetchabun meet, on the northern edge of Isaan. In Khao Kho, Phetchabun, home to Thailand’s largest Hmong community, it grows on sloping fields beside cabbages and maize.
Planted in April and May, it grows through the rainy season. After about eight months the leaves die back, and farmers dig the rhizomes by hand in December and January.
Daily use
Black ginger powder is strong: earthy, gently bitter and resinous, without the heat of ordinary ginger. A little goes a long way, and it tastes best in something rich.
Research at a glance
Black ginger is one of the most studied Thai plants. More than fifteen studies have tested it in people, most of them in Thailand and Japan. The largest group looks at physical fitness, others at body composition. The trials below were randomised and placebo-controlled and used concentrated extracts in capsules or drinks, not whole powder; the last row pools 16 studies.
| Study | Who took part | Daily amount | How long | What changed compared with placebo |
|---|---|---|---|---|
| Physical fitness | ||||
| Wattanathorn 2012 eCAM · Thailand | 45 healthy adults aged 60 and over | 25 or 90 mg extract | 8 weeks | Higher dose: better 30-second chair-stand and 6-minute walk tests. |
| Promthep 2015 Med Sci Monit · Thailand | 60 football players aged 15–18 | 180 mg extract | 12 weeks | Stronger hand grip. Sprint, flexibility and leg strength unchanged. |
| Yamana 2019 Yakuri to Chiryo · Japan | 34 healthy older adults | Extract in a food | 8 weeks | Longer distance in the 6-minute walk test. Other tests unchanged. |
| Onsiri 2020 Asian J Sports Med · Thailand | 57 air force cadets, about 20 years old | 360 mg extract | 12 weeks | Faster heart-rate recovery after exercise. Lactate threshold unchanged. |
| Sripanidkulchai 2022 J Diet Suppl · Thailand | 194 male sports-school students | 360 mg extract | 12 weeks | Stronger grip and back-leg strength, higher VO2max and a faster 50-metre sprint. The largest trial so far. |
| Wattanathorn 2023 Foods · Thailand | 60 healthy adults aged 19–60 | Drink with 90 or 180 mg extract | 12 weeks | Higher dose: higher VO2max and better shuttle-run and 5-minute-run results. |
| Body composition | ||||
| Yoshino 2018 DMSO · Japan | 74 adults with overweight | 150 mg extract | 12 weeks | Less abdominal fat, both visceral and under the skin. |
| Sung 2025 Front Nutr · Korea | 83 adults with overweight | 50 mg extract | 12 weeks | Lower body-fat mass and visceral fat; lean mass fell slightly in both groups. |
| Blood sugar | ||||
| Na Takuathung 2024 Nutr Res · meta-analysis | 16 human studies, 897 people | Different preparations | Varied | Modestly lower fasting blood sugar when the studies were pooled. |
What’s inside
Black ginger owes its character to two groups of compounds: methoxyflavones, which make it unusual among plants, and anthocyanins, which give it its colour. The Thai Herbal Pharmacopoeia uses the rhizome’s typical features to identify it.
The best-known methoxyflavone of black ginger, about 2 g per 100 g of dried rhizome in Thai samples.
Two further signature methoxyflavones. Their balance differs from plant to plant.
Researchers have identified 13 methoxyflavones in the rhizome, together about 4 g per 100 g dry weight.
Purple pigments, the same group that colours blueberries and red cabbage. They give the flesh and powder its violet tone.
Only a trace, about 0.03 g per 100 g. Borneol, camphene and camphor give its resinous, camphor-like scent.
Unlike true ginger, black ginger has no gingerols or shogaols, which is why it tastes earthy rather than hot.
| Component | Amount |
|---|---|
| Methoxyflavones, all 13 | about 4 g |
| of which 5,7-dimethoxyflavone | about 2 g |
| Flavonoids, 11 measured | 2.4–6.1 g |
| Essential oil | about 0.03 g |
| Water, pharmacopoeia limit | max. 10 g |
Methoxyflavones are fat-loving and dissolve poorly in water.
In laboratory tests they dissolve best in strong ethanol, much like the traditional Thai liquor infusion.
That is why milk, coconut milk and yoghurt suit the powder better than plain water.
What black ginger offers
From Hmong hill villages to laboratories in Thailand, Japan and Korea: as a powder, black ginger is easy to add to your morning coffee or yoghurt.
We state clearly what kind of study each result comes from. Both trials below were randomised, double-blind and placebo-controlled, and both reported positive results.
Foods · 2023
Human study · randomisedIn Thailand, 60 healthy adults aged 19–60 had a drink with 90 or 180 mg of extract, or a placebo, daily for 12 weeks. The higher dose raised VO2max, a measure of aerobic fitness, and improved running test results. Funded by the energy company PTT.
Frontiers in Nutrition · 2025
Human study · randomisedIn Korea, 83 adults with overweight completed 12 weeks of 50 mg extract or placebo daily. Body fat fell by about 340 g, against a gain of about 300 g with placebo; visceral fat also fell. Lean mass fell slightly too, so the authors advise adding exercise.
Educational product information. Not medical advice. Not for children. If you are pregnant, breastfeeding or taking medication, consult your doctor before using a new botanical product.
