Is Ashwagandha Safe To Take With Anastrozole?

In our latest question and answer, our pharmacist discusses whether or not anastrozole can be taken with ashwagandha.


Hello, can I take Ashwagandha if I’m taking anastrozole?

Asked by Denise On Jan 21, 2023

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Jan 25, 2023
Last updated Jan 25, 2023

Key points

  • There is no known interaction between ashwagandha and anastrozole.


Thanks for reaching out! There is no known interaction between Arimidex (anastrozole) and ashwagandha. 

Although it can sometimes be challenging to definitively know whether or not an herbal product will cause a drug interaction due to the lack of available data, based on everything I could find, they seem to be safe to take together.

Nevertheless, be sure to let your doctor know about everything you are taking so you can be appropriately monitored.

More Details

Drugs and herbs can interact in a variety of ways, including by affecting one or the other's metabolism and absorption, or by a combined or contradictory pharmacologic effect.

For example, the herb 'cat's claw' can inhibit a prominent CYP metabolizing enzyme known as CYP3A4, which could decrease the metabolism of other drugs that depend on the enzyme, potentially increasing the risk of side effects.

Ashwagandha isn't known to inhibit metabolizing enzymes to a clinically significant degree, and besides, anastrozole is not predominately metabolized by the CYP enzymes. It is metabolized via other methods (e.g occurs by N-dealkylation, hydroxylation, and glucuronidation) that ashwagandha isn't known to affect.

In fact, ashwagandha isn't known to interact with many prescription drugs. One of the few may be with thyroid medication but there is no evidence to suggest there are any issues with anastrozole. Ashwagandha is not known to affect estrogen levels either.

Final Words

Thanks again for contacting us. I hope this was helpful.

I want to reiterate that you should make sure your doctor knows of all the medications you are taking so you can be appropriately monitored.

While there is no known interaction with anastrozole, again, there just really isn't much data to make firm conclusions (even though it's likely they are safe together).


  • Efficacy and Safety of Ashwagandha Root Extract in Subclinical Hypothyroid Patients: A Double-Blind, Randomized Placebo-Controlled Trial, PubMed
  • An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures, PubMed
  • Anastrozole Monnograph, PubChem
  • Arimidex Prescribing Information, AccessFDA

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at! You can also connect with Dr. Brian Staiger on LinkedIn.

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