Saw Palmetto - Conjugated Estrogens, Methyltestosterone Interaction
Herbal: Saw Palmetto
Also Known As: Serenoa repens, American Dwarf Palm Tree, Baies du Palmier Scie, Cabbage Palm, Chou Palmiste, Ju-Zhong, Palmier Nain, Palmier Scie, Sabal, Sabal Fructus, Saw Palmetto Berry
Drug: Conjugated Estrogens, Methyltestosterone
Brand names:
Premarin with Methyltestosterone
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 18, 2025
Interaction Details
Conjugated Estrogens, Methyltestosterone is classified as belonging to the following category: Estrogens
Saw palmetto might reduce the effectiveness of estrogens.
Saw palmetto might have antiestrogenic effects. Theoretically, it might interfere with estrogens taken concomitantly.
Interaction Rating
Likelihood of Occurrence
PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Pharmacist Analysis
There is a possibility that saw palmetto, a commonly used herbal supplement, could have antiestrogenic effects, potentially interfering with estrogen drugs taken simultaneously.
This is based on research indicating that saw palmetto may have a regulatory effect on estrogen levels in the body, which could impact the effectiveness of estrogen-based medications.
More research is certainly needed but saw palmetto should be cautiously with estrogens.
- Dr. Brian Staiger, PharmDReferences
- Di Silverio F, D'Eramo G, Lubrano C, et al. Evidence that Serenoa repens extract displays an antiestrogenic activity in prostatic tissue of benign prostatic hypertrophy patients. Eur Urol 1992;21:309-14.
Saw Palmetto Overview
Saw palmetto (Serenoa repens) is a plant native to the southeastern United States and a member of the Arecaceae family. It is a small, palm-like tree with fan-shaped leaves that produces small, white flowers. The fruit of the plant is a small, dark purple berry, which is what is used in dietary supplements.
In traditional medicine, saw palmetto has been used to treat a variety of health conditions, including prostate problems (such as BPH [benign prostatic hyperplasia]) and urinary tract disorders. It is also claimed to have anti-inflammatory and antioxidant properties and to improve hair growth.
Saw Palmetto - More Interactions
Saw Palmetto interacts with 173 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
| Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
| Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
| Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
| Unknown | No interactions have been reported or no interaction data is currently available. |
Return to the main supplement interaction checker page
Parts of this content are provided by the Therapeutic Research Center, LLC.
DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
© 2021 Therapeutic Research Center, LLC
Drug descriptions are provided by MedlinePlus.
Ask A Pharmacist About Your Herbal Questions!
Dr. Brian Staiger, PharmD
In addition to being a clinical pharmacist specializing in pharmacotherapy, Dr. Brian Staiger is a registered herbalist through the American Herbalist Guild. He has combined his passion for pharmacy practice with the study of medical ethnobotany to improve patient care. Feel free to reach out about any of your herbal or medication questions!
Ask A Pharmacist