Solanaceae
Withania somnifera
Ashwagandha · Indian winter cherry
- Part used
- root
- Native range
- India, the Middle East, and dry parts of Africa
- Morphology
- A short shrubby perennial to about a metre and a half with dull green leaves and small green bell flowers, followed by orange-red berries in a papery husk. A nightshade, and it looks like one.
What is in it
Evidence
A growing body of small trials reports reductions in self-rated stress and improvements in sleep, with some effect on testosterone in men. The studies are mostly small, short, and heavily concentrated among researchers and sponsors in one region. Independent replication at scale is thin.
Safety
Hepatotoxicity is the significant emerging concern, with an increasing number of case reports including cholestatic liver injury, and regulatory warnings issued in Denmark and reviewed elsewhere. Thyroid hormone levels can rise. Contraindicated in pregnancy, where it has abortifacient use in traditional practice. Immunostimulant effects raise concern in autoimmune disease.
Interactions: Additive sedation with CNS depressants; May interact with thyroid medication; Theoretical opposition to immunosuppressants
Regulatory: Permitted as a listed medicine ingredient in Australia. Banned as a food supplement in Denmark; under review in several jurisdictions.
How the traditions classify it
Three systems, rating the same plant. Where they disagree, none of them is correcting the others — they are separate frameworks that arrived at their categories independently.
Historical use
In Ayurvedic use for around three thousand years as a tonic and rejuvenative, particularly for debility, and applied to a very wide range of complaints.
Recorded as history and attributed where possible. Long use establishes that a plant was widely used, not that it worked, and not that it was safe.
What it is taken for, and who says so
Sold for stress, anxiety and sleep, and separately marketed to men for testosterone and strength. It is currently among the fastest-growing supplements in the Western market.
Recorded because it is what people believe, not because it is what the plant does. Whether any of it holds up is the Evidence section above, and the two frequently disagree. A sincere account of feeling better is compatible with the plant doing nothing — see the placebo effect.
Worth knowing
Ashwagandha is the fastest-growing herbal supplement in the Western market, and its evidence and its safety literature are moving in opposite directions at the same time.
The trials are genuinely suggestive for stress and sleep. They are also small, short, and drawn from a narrow pool of investigators. Meanwhile the case reports of liver injury keep arriving, which is the pattern every widely adopted supplement produces once enough people take it for long enough — the harms are found by the market rather than before it.
It is a nightshade, and the family is worth noticing. Solanaceae contains the potato and the tomato alongside deadly nightshade, henbane and datura, which is a reminder that a plant family tells you where something sits on the tree of life and nothing at all about whether it is safe.
Nomenclature verified against GBIF backbone taxonomy.