May enhance sedative effects
Ashwagandha has GABAergic activity and may enhance the effects of sedatives, benzodiazepines, or sleep medications.
Use caution, start with lower doses of both.
Be aware of enhanced sedation
May enhance sedative effects. Use caution, start with lower doses of both.
Be aware of enhanced sedation
This interaction is rated “Warning” by Formulate. Ashwagandha has GABAergic activity and may enhance the effects of sedatives, benzodiazepines, or sleep medications.
Studies from our registry that mention ashwagandha or sedatives. Each links to the primary source and the other Formulate pages citing it.
Mentions ashwagandha · 2026
Memorial Sloan Kettering Integrative Medicine Monograph: Ashwagandha
Primary literature · Monograph
Documents thyrotoxicosis case reports associated with ashwagandha use. States ashwagandha may increase thyroxine levels. Also notes CYP3A4 induction (moderate) and sedative-additive effects. Does not give a hard avoid-with-levothyroxine warning but flags thyroid monitoring.
Mentions ashwagandha · 2022
Ashwagandha as a Unique Cause of Thyrotoxicosis Presenting with Supraventricular Tachycardia
Primary literature · Case report
Patient presented with supraventricular tachycardia and biochemical thyrotoxicosis after two years of self-administered ashwagandha. Full symptomatic and biochemical resolution after cessation, with no other intervention.
Mentions ashwagandha · 2019
An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract
Lopresti et al. · Medicine
240mg/day high-concentration extract produced significant cortisol and stress-score reductions at 60 days.
Mentions ashwagandha · 2019
An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract
Salve J, Pate S, Debnath K, Langade D · Cureus
8-week RCT (n=60) showed ashwagandha 250mg and 600mg daily significantly reduced perceived stress, serum cortisol, and improved sleep quality vs placebo, with greater effect at the higher dose.
Mentions ashwagandha · 2018
Efficacy and Safety of Ashwagandha Root Extract in Subclinical Hypothyroid Patients: A Double-Blind, Randomized Placebo-Controlled Trial
Sharma et al. · J Altern Complement Med
TSH decreased significantly (p<0.001); T3 increased significantly (p=0.0031); T4 increased significantly (p=0.0096). Direction of effect consistent with thyroid-stimulating action of ashwagandha.
Mentions ashwagandha · 2015
Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial
Wankhede et al. · Journal of the International Society of Sports Nutrition
300mg KSM-66 2x/day for 8 weeks increased muscle strength, size, and recovery vs placebo in resistance-trained men.
Guide
Ashwagandha Guide 2026: Clinical Evidence Reviewed
Learn which ashwagandha extract actually matches the RCT evidence — KSM-66, Sensoril, or generic powder — and what cortisol, anxiety, and testosterone data show.
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Other interactions to know
Ashwagandha can raise thyroid hormone levels and stack additively with levothyroxine, risking thyrotoxicosis.
Valerian adds to sedative medication effects
Ashwagandha may enhance SSRI effects
Piperine may enhance ashwagandha absorption
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Medical disclaimer. This page is for educational purposes only and does not replace advice from a qualified healthcare provider.
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