On TikTok and in supplement stores, ashwagandha is currently sold as a kind of miracle cure. Less stress, more energy, better sleep and, increasingly, less hair loss. It is even said to be a natural counterpart to finasteride, without the side effects.
The latter is the promise that interests us. Because if a supplement from the drugstore does the same as a DHT blocker, that would be big news. So we investigated what is actually known about it: what ashwagandha does to your body, and what the promise regarding hair growth is based on.
What exactly is ashwagandha?
Ashwagandha (Withania somnifera) is a plant that has been used for centuries in Ayurvedic medicine, especially as a remedy for stress and fatigue. It is called an adaptogen: a substance that is supposed to help the body cope better with stress. In recent years, Western research has also been conducted, particularly on its effect on cortisol and testosterone.
The effect on cortisol is reasonably well-substantiated
Of the claims surrounding ashwagandha, the cortisol-lowering effect is the best researched. In several randomized studies, participants' cortisol levels significantly decreased after a few weeks of ashwagandha, compared to a placebo group. A frequently cited study, for example, showed a clear decrease in people who took an extract of the root daily for 60 days.
This is relevant for hair loss, because prolonged stress can cause a form of hair loss called telogen effluvium: hair follicles accelerate into the resting phase, causing you to lose significantly more hair than normal a few months later. If ashwagandha indeed lowers cortisol levels, it could theoretically help to reduce this type of stress-related hair loss. To be clear: this is not a treatment for hereditary baldness, but something else.
The effect on testosterone is nuanced
This is where it gets interesting: several studies in men show that ashwagandha not only lowers cortisol, but also increases testosterone, sometimes by percentages between 15 and 20 percent compared to placebo.
At first glance, this sounds positive. More testosterone is often associated with vitality and muscle recovery, and that is also what many of these studies looked at. But for someone who is genetically predisposed to hereditary hair loss, a higher testosterone level is not an automatic advantage. Testosterone is converted into DHT in the hair follicle by the enzyme 5 alpha reductase, and DHT is the main driver of hair loss in men with a sensitive hairline. More testosterone in your body does not immediately mean more DHT on your scalp, but it is also not the direction you would expect from a product sold as a "natural DHT blocker."
Is ashwagandha a DHT blocker then?
Based on what is currently known: no, not in a way comparable to finasteride or saw palmetto. There is no human research that shows that ashwagandha inhibits the conversion of testosterone to DHT. A few in-vitro studies on Ayurvedic herbs have looked at 5 alpha reductase inhibition, but ashwagandha did not emerge as a strong candidate there; other plants such as Eclipta alba scored better.
In short: the claim that ashwagandha is a natural DHT blocker is not supported by good research. What is supported: lower cortisol, and in men possibly higher testosterone. These are different effects than what it is often sold for.
For whom can it then be useful?
If your hair loss is related to a stressful period, illness, or a major event, i.e., telogen effluvium, lowering your cortisol level can be a reasonable approach. Not because ashwagandha specifically works on your hair, but because it can dampen the underlying stress response. Less stress is rarely a bad idea anyway.
For men with hereditary hair loss, where DHT-sensitive hair follicles are at the core of the problem, there is no good reason to expect ashwagandha to change much. Addressing DHT requires something that actually targets that mechanism.