Oral research uses a particular extract
A single-center randomized trial enrolled 92 adults and had 83 complete follow-up. It tested KSM-66 root extract, 300 mg twice daily after meals, against placebo for 75 days and reported improved hair measures. This studied regimen is not a general prescription for alopecia. The supplier provided the extract. [1]
A serum trial answers a different question
A separate trial enrolled 68 adults, with 61 in its per-protocol analysis, and tested a serum containing 5% root extract over 75 days. Several hair measures improved compared with placebo. Five percent extract in a serum is not a 5% dose of isolated withanolides, and it is not interchangeable with swallowing capsules. [2]
Both studies leave important gaps
The studies were small, short and conducted at a single center; neither establishes durable benefit across diagnosed causes of hair loss. Supplied branded ingredients and limited follow-up warrant attention. No reported adverse events in a trial does not establish absence of uncommon harms. [1][2]
Match treatment to the cause
Imagine shedding starts suddenly after a new illness or medicine. Assessment of that change is more useful than choosing an extract dose from a cosmetic study. Oral ashwagandha can cause drowsiness, digestive effects and rare liver injury, and is unsuitable in several circumstances including pregnancy and thyroid disorders. [3]
| Regimen | Limit |
|---|---|
| 300 mg twice daily orally | One extract and selected adults |
| 5% extract serum | Different route and formulation |
| 75-day follow-up | Not long-term durability |
| Improved hair measurements | Not every hair-loss diagnosis |
Sources for this article
- A Prospective, Randomized, Double‐Blind, Placebo‐Controlled Clinical Study of Efficacy and Safety of Ashwagandha Root Extract Capsule on Skin and Hair Health in Healthy Adults - PMC
Source consulted: 2026-09-21. This is a reference resource, not a claim that we conducted the studies or tested a product. - Effects of Withania somnifera root extract serum application on hair health in healthy adults: A prospective, double-blind, randomized, parallel, placebo-controlled study - PMC
Source consulted: 2026-09-21. This is a reference resource, not a claim that we conducted the studies or tested a product. - Ashwagandha: Usefulness and Safety | NCCIH
Source consulted: 2026-09-21. This is a reference resource, not a claim that we conducted the studies or tested a product.