Does Saw Palmetto Interact With Estradiol?
In our latest question and answer, the pharmacist discusses the potential interaction between saw palmetto and estradiol.
Can saw palmetto interact with estradiol and cause side effects like headaches? Thanks!
Jun 02, 2024- Saw palmetto may have anti-estrogenic activity and could potentially interact with estradiol by affecting estrogen levels. There is limited research available about how clinically significant this interaction is or what specific effects it might cause. You should speak with your doctor before taking saw palmetto with estradiol so you can be appropriately monitored.
Answer
Thank you for your question! Our drug-herbal interaction checker does show an interaction between saw palmetto and estradiol (Saw Palmetto - Estradiol Interaction Details | HelloPharmacist). Studies indicate that saw palmetto may have anti-estrogenic activity and therefore may interact with estrogen-containing drugs, such as estradiol.
We based our 'moderate interaction' rating between saw palmetto and estrogens on several studies, including one published in European Urology (Evidence that Serenoa repens extract displays an antiestrogenic activity in prostatic tissue of benign prostatic hypertrophy patients - PubMed (nih.gov)).
In this study, one group of individuals received saw palmetto extract, while the other received a placebo for three months. Researchers examined how the treatment affected estrogen and androgen receptors in prostate tissue. They found that saw palmetto significantly reduced certain estrogen receptor levels compared to the untreated group. This suggests that saw palmetto might have antiestrogenic effects.
It is certainly possible that if you take both estrogen and saw palmetto, estrogen levels may be affected, which could cause side effects, such as the headache you mentioned in your question.
It is important to note that while the interaction between saw palmetto and estradiol is possible, we don't know how clinically significant it is due to the overall lack of data. Our interaction checker is based on available literature, but there isn't much to go off of, unfortunately.
While there may be concern about taking saw palmetto with estradiol, it is very challenging to say exactly what the effects may be and if it could cause an increase in side effects or reduce the effectiveness of estrogen therapy.
I always highly recommend speaking to your doctor before combining supplements with your medication so you can be appropriately monitored.
Final Words
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References & sources
- Evidence that Serenoa repens extract displays an antiestrogenic activity in prostatic tissue of benign prostatic hypertrophy patients — PubMed
- Activity and isolated phytoestrogen of shrub palmetto fruits (Serenoa repens Small), a new estrogenic plant — PubMed
- Myristoleic acid, a cytotoxic component in the extract from Serenoa repens, induces apoptosis and necrosis in human prostatic LNCaP cells — PubMed
Glossary — Terms in This Answer
- Saw palmetto
- A plant supplement derived from the saw palmetto berry, commonly used to support prostate health.
- Estradiol
- A form of estrogen, a female hormone used in medications for hormone replacement therapy and other conditions.
- Anti-estrogenic activity
- The ability of a substance to block or reduce the effects of estrogen in the body.
- Estrogen-containing drugs
- Medications that contain or are based on estrogen, a hormone that affects reproductive and other body functions.
- Androgen receptors
- Proteins in cells that bind to male hormones and allow those hormones to affect cell function.
- Prostate tissue
- The cells and structures that make up the prostate gland, which is part of the male reproductive system.
- Estrogen receptor levels
- The amount of proteins in cells that bind to estrogen and carry out its effects in the body.
- Clinically significant
- Important enough to produce noticeable effects on a patient's health or symptoms in real-world medical practice.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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