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Topical Finasteride (Generic Propecia) Side Effects

Kristin Hall, FNP

Reviewed by Kristin Hall, FNP

Written by Rachel Sacks

Published 02/19/2021

Updated 09/22/2023

Once you hit the age of 50, several things, both good and bad, happen. You’re eligible to sign up for AARP, you can use the excuse “I’m too old” to get out of things and there’s a good chance you’ll be experiencing some degree of hair loss.

The most common form of hair loss, male pattern baldness (also called androgenetic alopecia or AGA) affects up to 50 percent of men by age 50. Welcome to the club!

Fortunately, there are ways to treat male pattern baldness. The oral medication finasteride (brand name Propecia®) is a common recommendation and is one of two FDA-approved medications for the treatment of androgenetic alopecia.

But oral finasteride has known sexual side effects like decreased libido and erectile dysfunction from the oral tablet, so using a topical finasteride treatment could be a preferable alternative for some people.

However, topical finasteride has yet to receive FDA approval and there’s very limited research on its benefits or even how it works. That all leads to some pressing questions that need to be answered: Does topical finasteride have side effects? And perhaps more importantly, is topical finasteride safe?

Topical Finasteride Side Effects Explained

Before we look into topical finasteride side effects, let’s first look at how topical finasteride works to manage male pattern baldness.

The receding hairline or thinning hair that signals hair loss is caused by enzymes that convert testosterone into the male sex hormone dihydrotestosterone (DHT), a major androgen.

High DHT levels cause the hair follicles — the tiny organs throughout your scalp from which your hair grows — to shrink, leading to baldness.

Finasteride belongs to a group of medications called 5-alpha reductase inhibitors. These medications prevent the conversion of testosterone to dihydrotestosterone, which can prevent further hair loss.

But while oral finasteride takes effect through systemic absorption (absorption by every part of the body — skin, hair, liver, etc.), the topical formulation provides localized treatment, just on your scalp.

Every medication can have potential side effects. If you’ve ever looked up finasteride side effects, you may have seen common adverse effects like sexual dysfunction, reduced ejaculation or even insomnia from finasteride. However, these are most often from oral finasteride.

But is topical finasteride safe and effective? Does it have different side effects? There’s a little bit of research that has looked at these questions.

A clinical study that compared the effects of oral finasteride against a finasteride 0.25% topical solution was carried out on 24 men with androgenetic alopecia.

The men who applied the topical finasteride solution to their scalps for one week showed similar results to those who took 1mg of oral finasteride for the same amount of time. Specifically, scalp DHT was reduced by 68 to 75 percent when topical finasteride was used, compared to 62 to 72 percent with the oral tablet. Researchers also found that the topical solution was well-tolerated.

Another study in the Indian Journal of Dermatology comparing the effects of topical finasteride gel to the oral tablet form was carried out on 45 men with androgenetic alopecia. The patients used the gel twice a day for six months, while the finasteride tablets were used once a day.

topical finasteride

take on hair loss with an easy-to-use spray

By the end of the study, both groups saw similar positive effects on hair growth.

Finally, a study of more than 440 patients that looked at the effectiveness of a topical finasteride spray compared to the oral tablet found that the spray significantly improved hair count compared to placebo, but had less of an impact on serum DHT levels than the oral version.

While all these studies show promising results for the effectiveness of topical finasteride, many are too small to gauge if a finasteride spray would really encourage hair regrowth. 

But what about topical finasteride spray side effects or adverse effects of a finasteride gel?

Topical finasteride, like all medications, can lead to some side effects. But many of these studies reported that the hair loss treatment was well-tolerated, with a few minor side effects, including:

  • Lightheadedness

  • Headaches

  • Redness at application site

  • Scalp itching

  • Irritation

Although much rarer, serious side effects are possible. For example, two subjects in the first study reported increased levels of alanine transaminase — a dangerous situation for the liver with high, frequent daytime urination and testicular pain.

And while we can all appreciate a moment of craftiness, we have to urge that you don't make your own topical finasteride.

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Maybe you’re so frustrated with your hair loss and you want to double down on treatment efforts by combining topical finasteride with another hair loss product. But is topical finasteride safe when used with other hair loss treatments?

Besides oral finasteride, the other medication that’s approved by the FDA for male pattern hair loss is minoxidil.

Minoxidil, a topical solution, stimulates hair growth by encouraging blood flow to your hair follicles. It’s also thought that minoxidil lengthens the growth phase of your natural hair growth cycle.

In a study to test the effectiveness of a treatment that combined topical finasteride, dutasteride (another 5-alpha reductase inhibitor) and topical minoxidil, 15 male patients applied a mix of these products for nine months.

Those who used the topical finasteride treatment, dutasteride and minoxidil solution saw hair growth after three months. This combination was well-tolerated, even in patients with a tendency for allergies.

If you’re looking for a combination solution to treat hair loss, we offer a topical finasteride & minoxidil spray.

Or you can try minoxidil on its own, available as either a minoxidil foam or liquid minoxidil solution drops, both of which are applied directly to the scalp.

If you’re looking for more ways to encourage hair growth or boost thin hair, adding supplements like biotin gummies can lead to a fuller head of hair.

You can also try hair products like a thickening shampoo with saw palmetto or this volumizing shampoo and conditioner duo for thinning hair to give your locks some lift.

Hair loss treatments, delivered

While FDA-approved to treat male hair loss, oral finasteride can cause side effects like sexual dysfunction. Therefore, some may opt for a topical finasteride treatment option to reduce the risk of those systemic side effects. 

But is topical finasteride safe, and what side effects can you expect? Here’s what you need to know.

  • Finasteride works to block the conversion of testosterone into the hormone dihydrotestosterone (DHT), which causes male pattern baldness. While often prescribed as an oral tablet, topical finasteride solutions are available (but not FDA-approved).

  • While there haven’t been any large studies of the effects of topical finasteride, multiple smaller studies have shown that it significantly improved hair count and hair density, with lower risk of side effects.

  • There can be some side effects of topical finasteride though, such as irritation, an itching or burning sensation, lightheadedness or redness where the solution is applied.

You can learn more about topical finasteride use, from how to apply it to safety measures, in our full guide. We’ve also covered the effectiveness of topical finasteride and gone more in-depth on the side effects of oral finasteride.

If you want to explore more hair loss treatments, you start by connecting with a dermatologist or healthcare provider today.

9 Sources

  1. Asfour, L., Cranwell, W., Sinclair, R. Male Androgenetic Alopecia. [Updated 2023 Jan 25]. In: Feingold KR, Anawalt B, Blackman MR, et al., editors. Endotext [Internet]. South Dartmouth (MA):, Inc.; 2000-. Retrieved from
  2. Zito, P.M., Bistas, K.G., Syed, K. Finasteride. [Updated 2022 Aug 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Retrieved from
  3. Mysore V. (2012). Finasteride and sexual side effects. Indian dermatology online journal, 3(1), 62–65. Retrieved from
  4. Ustuner E. T. (2013). Cause of androgenic alopecia: crux of the matter. Plastic and reconstructive surgery. Global open, 1(7), e64. Retrieved from
  5. Caserini, M., Radicioni, M., Leuratti, C., & Annoni, O. (2014). A novel finasteride 0.25% topical solution for androgenetic alopecia: Pharmacokinetics and effects on plasma androgen levels in healthy male volunteers. International Journal of Clinical Pharmacology and Therapeutics. Retrieved from
  6. Hajheydari Z, Akbari J, Saeedi M, Shokoohi L. (2009). Comparing the therapeutic effects of finasteride gel and tablet in treatment of the androgenetic alopecia. Indian J Dermatol Venereol Leprol, 75(1), 47-51. Retrieved from
  7. Piraccini, B. M., Blume-Peytavi, U., Scarci, F., Jansat, J. M., Falqués, M., Otero, R., Tamarit, M. L., Galván, J., Tebbs, V., Massana, E., & Topical Finasteride Study Group (2022). Efficacy and safety of topical finasteride spray solution for male androgenetic alopecia: a phase III, randomized, controlled clinical trial. Journal of the European Academy of Dermatology and Venereology : JEADV, 36(2), 286–294. Retrieved from
  8. Rafi, A. W., & Katz, R. M. (2011, May 10). Pilot Study of 15 Patients Receiving a New Treatment Regimen for Androgenic Alopecia: The Effects of Atopy on AGA. Retrieved from
  9. Patel, P., Nessel, T.A., Kumar, D. D. Minoxidil. [Updated 2023 Aug 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Retrieved from
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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