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Finasteride Interactions Guide

Kristin Hall, FNP

Reviewed by Kristin Hall, FNP

Written by Geoffrey Whittaker

Published 02/01/2021

Updated 08/17/2023

The science is real: Finasteride is a safe and effective way for men to treat hair loss — as long as they’re mindful of side effects, drug interactions and other risks. 

Clinical trials and other research show that finasteride (also known as Propecia®) is proven to treat male pattern baldness (androgenetic alopecia). It works by inhibiting an enzyme called 5-alpha reductase and reducing a key compound in the reduction of hair growth: dihydrotestosterone, also known as DHT.

Finasteride is an oral and topical reductase inhibitor used daily, either in the form of finasteride tablets or a topical solution. When used correctly, it can reduce DHT levels by more than 90 percent in some cases — slowing the progress of male pattern hair loss.

But that reduction is not without risks. One of the primary sources of risk is interactions with other medications. 

Worried your heart disease, liver disease or other medications might bring unforeseen problems when crossed with finasteride? We’ve got you covered. 

Below we’ll go over drug interactions, side effects, medical conditions and other risks associated with finasteride and provide tips on how to stay safe when using it.

Let’s dive in so you can get back to handling your hair growth priorities.

Let’s get the good news out of the way early on: According to the FDA (U.S. Food and Drug Administration), there are no major interactions associated with finasteride you need to worry about. 

The FDA’s drug information guide for finasteride says that “no drug interactions of clinical importance have been identified.” That’s really good news, especially for anyone who’s listened to the auctioneer barking side effect warnings at the end of an antidepressant commercial.

The primary concern when using finasteride alongside other medications is accidentally causing unusually high concentrations of the drug in your blood, which can lead to more serious side effects.

Those side effects may include: 

  • Skin irritation in the topical formulation

  • Sexual side effects like reduced libido

  • Allergic reactions

While sexual side effects can occur, some of the claims are over the top and would be considered part of the myths and facts about finasteride side effects. The truth is that in clinical studies, less than 2 percent of finasteride users experienced erectile dysfunction, a decrease in libido or an ejaculation disorder.

If you’re one of the few people who experience side effects as a result of taking finasteride, contact your healthcare provider for further instructions.

Oh, and here’s a little extra good news: Some drugs can compound the positive effects of finasteride, including minoxidil, commonly known as Rogaine®. 

Minoxidil isn’t a DHT blocker. Instead, it works by increasing blood flow to the parts of your body that need it most.

Since it doesn’t have the same mechanism of action as finasteride, using the two together can increase the effectiveness of both compounds in fighting and even potentially reversing the effects of hair loss.

With this in mind, hair loss treatments like minoxidil foam and minoxidil solution might be great additions to your hair loss treatment plan.

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Now for the bad news: Finasteride may not play well with certain health conditions.

The first two categories that might be a red flag for finasteride are urologic and liver issues. If a patient has known liver issues or urinary issues, they may not be able to take finasteride safely — any conditions or medications related to these issues should be shared with a healthcare provider before taking finasteride.

There’s also a potential relationship to breast cancer for both men and women that’s been noted in research, as well as breastfeeding risks that led to nipple discharge in infants.

We should note Propecia is not FDA-approved for treatment in women. Also, finasteride is contraindicated in pregnant women, so those who are pregnant or trying to conceive should avoid any contact with the tablets.

Here’s the scariest and simultaneously rarest concern: A slightly increased risk of high-grade prostate cancer. Prostate cancer and prostate enlargement have been associated with 5-alpha reductase inhibitors like dutasteride.

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These issues have also been associated with finasteride in research, but that was at a dosage of 5 milligrams, which is significantly higher than the recommended dose of 1 milligram.

It’s also worth noting that a small number of men who take finasteride continue to experience some side effects even after cessation of treatment. This has been occasionally referred to as post-finasteride syndrome.

Generally speaking, you should share all types of medications you’re taking with a healthcare provider to get the appropriate medical advice to stay safe. A single dose of finasteride could have adverse interactions with anything you’re taking, whether it’s over-the-counter supplements, FDA-approved prescription drugs or anything in between.

Better safe than sorry.

Hair loss treatments, delivered

Trying to nail down the big picture on how to stay safe? We’ve got some tips below.

But first, let us leave you with some parting bullet points:

  • Finasteride is available in both generic form and under several brand names like Propecia. It also comes as a medication for benign prostatic hyperplasia (enlarged prostate) in the form of Proscar.

  • It’s considered overall very safe and effective to use.

  • Finasteride can be used in conjunction with other treatments, including chemical and clinical therapies and lifestyle changes. It can also be used alongside minoxidil. 

  • Per finasteride’s FDA label, there are no major drug interactions associated with this drug.

  • You should consult your healthcare provider before using finasteride and clarify what, if any, medications you’re taking that might cause problematic interactions.

Here’s how to stay safe when taking finasteride: 

Ready to get started? We offer both oral finasteride tablets and a topical finasteride & minoxidil spray to combat male pattern baldness. Reach out today to learn more.

7 Sources

  1. Zito PM, Bistas KG, Syed K. Finasteride. [Updated 2022 Aug 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:
  2. Salisbury BH, Tadi P. 5-Alpha-Reductase Inhibitors. [Updated 2023 Apr 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:
  3. HIGHLIGHTS OF PRESCRIBING INFORMATION: PROPECIA® (finasteride) tablets for oral use. (n.d.).
  4. Singh, M. K., & Avram, M. (2014). Persistent sexual dysfunction and depression in finasteride users for male pattern hair loss: a serious concern or red herring?. The Journal of clinical and aesthetic dermatology, 7(12), 51–55.
  5. Suchonwanit, P., Thammarucha, S., & Leerunyakul, K. (2019). Minoxidil and its use in hair disorders: a review. Drug design, development and therapy, 13, 2777–2786.
  6. Diviccaro, S., Melcangi, R. C., & Giatti, S. (2019). Post-finasteride syndrome: An emerging clinical problem. Neurobiology of stress, 12, 100209.
  7. Kinter KJ, Anekar AA. (2023). Biochemistry, Dihydrotestosterone. Treasure Island (FL): StatPearls Publishing.
Editorial Standards

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references. See a mistake? Let us know at [email protected]!

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.

Kristin Hall, FNP

Kristin Hall is a board-certified Family Nurse Practitioner with decades of experience in clinical practice and leadership. 

She has an extensive background in Family Medicine as both a front-line healthcare provider and clinical leader through her work as a primary care provider, retail health clinician and as Principal Investigator with the NIH

Certified through the American Nurses Credentialing Center, she brings her expertise in Family Medicine into your home by helping people improve their health and actively participate in their own healthcare. 

Kristin is a St. Louis native and earned her master’s degree in Nursing from St. Louis University, and is also a member of the American Academy of Nurse Practitioners. You can find Kristin on LinkedIn for more information.

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