Piperine may enhance ashwagandha absorption
Piperine from black pepper inhibits glucuronidation and enhances bioavailability of many supplements including ashwagandha. May increase effectiveness.
Can take ashwagandha with piperine for enhanced absorption.
Take together
Piperine may enhance ashwagandha absorption. Can take ashwagandha with piperine for enhanced absorption.
Take together
This interaction is rated “Synergy” by Formulate. Piperine from black pepper inhibits glucuronidation and enhances bioavailability of many supplements including ashwagandha. May increase effectiveness.
Studies from our registry that mention ashwagandha or black pepper. 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.
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Other interactions to know
Ashwagandha can raise thyroid hormone levels and stack additively with levothyroxine, risking thyrotoxicosis.
May enhance sedative effects
Ashwagandha may enhance SSRI effects
Piperine increases curcumin absorption by 2000%
Check your full stack in the free interaction checker.
The free checker lets you add any combination of supplements and medications at once. The free web app goes further — every stack change surfaces interaction alerts automatically.
Medical disclaimer. This page is for educational purposes only and does not replace advice from a qualified healthcare provider.
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