Ashwagandha: what it does and what to watch
Also known as: Winter cherry, Withania somnifera · Herbal supplement (adaptogen tradition) · Updated 2026-08-20 · Educational — not medical advice
In plain language: This root is classified in traditional practice as a rasayana, or restorative tonic, and is now widely sold as an adaptogen, meaning a substance believed to help the body handle stress more evenly. Modern research has looked at possible effects on stress-hormone levels and sleep quality, with a number of small clinical trials reporting improved sleep and lower self-reported stress scores over several weeks of use. The trials are generally short, vary in the extract and amount used, and are not large enough to be considered definitive, so the evidence is best described as promising rather than settled.
What it's used for
- Traditionally taken for stress and sleep
- Marketed for reducing everyday anxiety and tension
- Used in traditional practice to support stamina and vitality
- Sometimes taken to support a calmer mood
Common side effects
- Drowsiness or daytime sleepiness
- Upset stomach or nausea
- Diarrhea
- Headache
- Reduced appetite
Get medical help if…
Changes in thyroid hormone levels, which can raise thyroid hormone in some users and complicate existing thyroid conditions or thyroid medicine dosing
Rare reports of liver injury, including jaundice and unusual fatigue, in people using concentrated extracts
Excess sedation when combined with sleep aids, anti-anxiety medicines, or alcohol
A drop in blood pressure in people already prone to low blood pressure
Avoidance is generally advised during pregnancy due to reports of effects on the uterus
Lab values it can move
Few guides tell you this part: medicines show up in blood work. If you take Ashwagandha and a value below looks off on your report, this may be part of the story — never stop a medicine without your doctor.
Some users see a shift in thyroid-stimulating hormone as thyroid hormone output changes, which matters most for people already being monitored or treated for a thyroid condition.
TSHLiver enzymes have risen in a small number of reported cases, usually linked to concentrated extract products rather than traditional preparations.
SGPT (ALT)Good to know
- Tell a doctor about thyroid conditions or thyroid medicine before starting, since thyroid hormone levels can shift
- Avoid combining with sedating medicines or alcohol without medical advice, since the sedative effect can add up
- Avoid use during pregnancy
- Supplement quality and strength vary between brands since these products are far less tightly regulated than prescription medicines
- Mention this supplement to a doctor before any surgery or when starting new prescription medicines
Questions people ask
Can ashwagandha affect my thyroid tests?
It can. Several reports describe a rise in thyroid hormone levels after regular use, which can be a problem for people with an overactive thyroid or those on thyroid medicine whose dose depends on stable lab readings. Anyone with a known thyroid condition should mention ashwagandha use to whoever is monitoring their thyroid function.
Is it safe to take with sleep medicine?
Caution is warranted. Ashwagandha has a mild sedative effect on its own, and combining it with prescription sleep aids, anti-anxiety medicines, or alcohol can add up to excessive drowsiness or impaired coordination the next day. A doctor or pharmacist can advise on timing and whether combining them makes sense for a particular situation.
Taking Ashwagandha? See what your blood work says.
Upload your lab report — every value checked and explained. Free — no account needed.