Research review
Can you take ashwagandha and milk thistle together?
No trial has tested ashwagandha and milk thistle taken together, and no trial has tested whether milk thistle protects against ashwagandha's documented, uncommon liver-injury risk. Ashwagandha and milk thistle are two unrelated plants from different families — not the same herb, whatever the name similarity suggests — and each has its own separate research.
No trial has tested ashwagandha and milk thistle taken together, and no trial has tested whether milk thistle protects against ashwagandha's documented, uncommon liver-injury risk. The two aren't the same plant, either — ashwagandha and milk thistle come from unrelated botanical families, each with its own separate research.
What the evidence doesn't support
It doesn't support milk thistle as a protective measure against ashwagandha's liver-related risk — nobody has tested that. It doesn't support any tested interaction between the two herbs, positive or negative; that combination hasn't been studied. And it doesn't support the idea that ashwagandha and milk thistle are the same plant, or interchangeable — they aren't, despite sometimes appearing side by side in search results and supplement blends.
Two different plants
Ashwagandha (Withania somnifera) is a member of the nightshade family, and supplements use its root. Milk thistle (Silybum marianum) is a member of the daisy family, and supplements use its seed. They're unrelated plants, studied for different things — ashwagandha mostly for stress and sleep-related outcomes, milk thistle mostly for liver and kidney disease markers — and neither substitutes for the other.
What the trials found
The research connecting these two isn't about a combination — it's about ashwagandha's own safety profile, which is why people researching milk thistle alongside it are often looking for reassurance. A 2026 review of ashwagandha's adverse effects, covering both preclinical and clinical evidence, documents gastrointestinal side effects, immune hypersensitivity, liver toxicity, and endocrine disruption, particularly with prolonged or high-dose use. The review explains that ashwagandha's bioactive compounds can be converted by liver enzymes into reactive intermediates linked to oxidative stress and hepatotoxicity, and calls for better dosing standards, more rigorous trials, and stronger safety monitoring. Separately, a published case report described a patient with a preexisting liver condition who developed acute-on-chronic liver failure associated with taking ashwagandha — a single case, not a trial, but one the authors present as part of a broader, rising pattern of ashwagandha-associated liver injury reports in the literature.
Neither of these sources tested milk thistle at all. No trial has given people ashwagandha and milk thistle together to see whether milk thistle offsets, reduces, or has any effect on ashwagandha's documented liver-related risk.
Questions people ask
Can you take ashwagandha and milk thistle together?
No trial has tested the combination, so there's no evidence either way about a benefit or an interaction. Nothing in the ashwagandha safety literature specifically flags milk thistle as a problem, but that's an absence of data, not a tested green light.
Is ashwagandha milk thistle?
No. They're unrelated plants — ashwagandha is a nightshade-family root, milk thistle is a daisy-family seed — with separate research bases and separate uses.
Does milk thistle protect the liver from ashwagandha?
That hasn't been tested. Ashwagandha's documented liver-injury reports are uncommon but real; no trial has given milk thistle alongside ashwagandha to see whether it changes that risk.
When to talk to a doctor
Anyone with a preexisting liver condition should talk to a doctor before starting ashwagandha, given the documented, if uncommon, association with liver injury described above. Milk thistle is not a treatment for liver injury and hasn't been tested as a way to prevent it. If you notice symptoms like unusual fatigue, yellowing skin or eyes, dark urine, or abdominal pain while taking ashwagandha, stop and see a doctor rather than adding another supplement.
Related reading: milk thistle benefits: what the research does and doesn't show and milk thistle and medications: what to check.
Sources
- Potential Adverse Effects of Ashwagandha: A Critical Review of Preclinical and Clinical Evidence A 2026 review of ashwagandha's safety literature found documented reports of liver toxicity, along with gastrointestinal, immune and endocrine effects, particularly with prolonged or high-dose use, and called for better dosing standards and safety monitoring.
- Changing perspectives: unveiling the risks of ashwagandha-induced hepatotoxicity A published case report described a patient with a preexisting liver condition who developed acute-on-chronic liver failure associated with taking ashwagandha — a single case, not a trial, but one the authors present as part of a wider pattern of ashwagandha-associated liver injury reports.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.