Ashwagandha Interactions With Medicines: Sedatives, Immunosuppressants, Diabetes and Blood Pressure Medicines

Safety first. Ashwagandha (Withania somnifera (L.) Dunal, family Solanaceae; supplements use the root, the leaf or both) is a plant, and "natural" does not mean it cannot interact with medicines. [1][2] The U.S. National Center for Complementary and Integrative Health (NCCIH) says there is evidence that ashwagandha might interact with some medications. [2] If you take any prescribed medicine, ask the prescriber or a pharmacist before you start, and never stop or change a prescribed medicine on your own. If you are struggling with anxiety or depression and feel unsafe, call or text 988 (U.S. Suicide & Crisis Lifeline), or call 911 in an emergency.

How to read this page

Interaction warnings come in different strengths, and this page keeps them apart. How interactions are classed is explained on its own page. Here we use three plain labels:

• Reported in people: a case report or a trial describes a problem or a measured change.
• Lab or animal only (preclinical): a cell or animal study suggests an effect; it may not happen in people.
• Named as possible: a health agency lists a medicine group, and the page we read does not say how big the risk is.

What the sources name

Sedatives, sleep medicines and anti-seizure medicines

Drowsiness is a listed effect of ashwagandha on its own. [2] Memorial Sloan Kettering suggests people who take benzodiazepines, anticonvulsants or barbiturates should likely avoid ashwagandha, because it "may have both sedative and GABAnergic effects". [4] That advice rests on preclinical work, and the same source says the clinical relevance has yet to be determined. [4] The practical point: if a medicine already makes you sleepy, tell the prescriber that you are considering ashwagandha, and be careful with driving. For more, see sleep safety and sedating products.

Immunosuppressants and autoimmune conditions

NCCIH names immunosuppressants as a possible interaction. [2] Memorial Sloan Kettering lists a kidney transplant rejection in a 69-year-old patient "associated with use of ashwagandha". [4] One report cannot prove cause, and the sources we read do not give a mechanism. The page on surgery and autoimmune disease covers this further.

Diabetes and blood pressure medicines

NCCIH names both groups. [2] For blood sugar, a 2026 meta-analysis of 11 trials (667 people) found ashwagandha "may modestly reduce FBG" (fasting blood glucose), but the certainty was very low and the authors said it precluded clinical recommendations. [5] So the effect size is small on average and uncertain. For blood pressure medicines, Proper evidence not found in the sources we read: we found the agency warning but no trial of ashwagandha with a named blood pressure medicine.

Thyroid medicines and lab tests

NCCIH names thyroid hormone medicines. [2] Memorial Sloan Kettering lists "May increase thyroxine levels" and "May cause false elevation in digoxin immunoassay" as laboratory effects. [4] A false lab reading can mislead a clinician, so mention ashwagandha before blood tests. See ashwagandha and the thyroid.

Medicines cleared by liver enzymes

This is lab-only territory. In human liver microsomes, "No significant interactions have been reported" with CYP3A4 or CYP2D6, while another lab finding was that ashwagandha was a moderate inducer of CYP3A4 in vitro; the clinical relevance is "not known". [4] Treat it as unresolved, and ask a pharmacist about your specific medicine.

Alcohol, other supplements and hormone-sensitive cancer treatment

• Alcohol: Proper evidence not found. We searched PubMed for ashwagandha with alcohol, sedation and GABA, and read the NCCIH and Memorial Sloan Kettering pages; none addresses alcohol directly. One reported liver case followed "multiple supplements which included ashwagandha, in addition to alcohol and ibuprofen", so the cause cannot be separated. [4]
• Other supplements: in a liver-injury series, four of five patients took other supplements, and in one case rhodiola was a possible cause alongside ashwagandha. [6] See amounts and duplicate ingredients.
• Prostate cancer treatment: ashwagandha "may increase testosterone levels" and should be avoided in hormone-sensitive prostate cancer. [4] NCCIH agrees. [2]

What to do

Bring the bottle to a pharmacist: the part of the plant (root or leaf), the extract, and every other ingredient. Ask about each medicine you take. Talking with a health professional has a short list of questions. The wider picture is in the ashwagandha guide and adaptogen medicine interactions.