Grapefruit With Finasteride Interaction

In our latest question and answer, the pharmacist discusses the interaction between grapefruit and finasteride.

Question

Can you eat grapefruit if you are taking finasteride for female hair loss (one pill daily)?

Asked by sheldon On Jul 06, 2024

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Jul 07, 2024
Last updated Jul 18, 2024

Answer

Thank you for reaching out to us!

This is an interesting question to answer because we do list an interaction on our website (Grapefruit - Finasteride Interaction Details | HelloPharmacist) between grapefruit and finasteride. However, this interaction is displayed based on the known mechanism of grapefruit and finasteride. In a real-world setting, it doesn't appear clinically significant.

Details

Grapefruit juice is known to interact with many medications by inhibiting CYP3A4, an enzyme responsible for drug metabolism. This inhibition can lead to increased drug levels in the bloodstream and a higher risk of side effects.

Grapefruit interactions are well-known and widely reported. For instance, the interaction between grapefruit and certain 'statin' cholesterol medications has been extensively published in academic journals and mainstream media alike (e.g., The dangers of grapefruit juice - The New York Times (nytimes.com)). 

When it comes to finasteride, which is metabolized by CYP3A4, the situation is a little different, and honestly, surprising.

Research and clinical trials, including a comprehensive 4-year study involving over 3,000 participants, have shown no significant interactions between finasteride and other drugs, even with grapefruit, a known inhibitor of CYP3A4. Even the prescribing information (LABEL (fda.gov)) reports no significant drug interactions.

This is likely due to finasteride's unique mechanism of action and its broad therapeutic window, which provides a safety margin against potential interactions.

In practice, while finasteride is processed by the same enzyme that grapefruit juice affects, the interaction is not considered clinically significant.

Although it's likely you can safely consume grapefruit while taking finasteride for female hair loss, it's always a good idea to discuss your specific circumstances with your healthcare provider, especially if you are taking multiple medications or have other health conditions.

Final Words

Thanks again for reaching out and please do so again anytime.

References

  • Propecia Prescribing Information, AccessFDA
  • Grapefruit juice increases serum concentrations of atorvastatin and has no effect on pravastatin, PubMed
  • Comparison of the efficacy and safety of finasteride in older versus younger men with benign prostatic hyperplasia, PubMed

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 [email protected]! You can also connect with Dr. Brian Staiger on LinkedIn.

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