Finasteride Transgender: Effectiveness and Interaction with Gender-Affirming Care

Key takeaways:

• Finasteride can treat hormone-related hair loss in trans men and women and reduce unwanted body hair.

• Under medical supervision, it can be used as part of gender-affirming therapy.

• A healthcare provider can offer guidance on taking finasteride and how it might affect or interact with other hormone therapies.

Finasteride is typically celebrated for its ability to treat hair loss and benign prostatic hyperplasia (BPH). The medication is also sometimes used by transgender individuals as part of gender-affirming hormone therapy (GAHT).

Finasteride for trans men and trans women can serve different purposes and have different effects. Finasteride alters hormone levels, and hormones affect everything from hair loss to body hair to breast development.

We’ll cover the basics of finasteride, plus the potential role of finasteride for transgender health, hair restoration, and gender-affirming care.

Finasteride is part of a class of medications called 5 alpha-reductase inhibitors (5ARIs). 5ARI is an enzyme that converts testosterone into another male sex hormone, dihydrotestosterone (DHT). 5ARIs block (or inhibit) this conversion.

What does this have to do with hair loss? Quite a lot. DHT plays an important role in early development (it helps form male sex organs during fetal development and later helps to deepen the voice). It also binds to signaling male hormones (called androgen receptors) within hair follicles, which can cause hair thinning.

Finasteride stops DHT from getting into the hair follicle in the first place.

Oral finasteride (the active ingredient in Propecia^®) is one of two medications approved by the Food and Drug Administration (FDA) for treating male pattern baldness (also called androgenetic alopecia, or AGA).

Topical finasteride is used off-label for hair loss but hasn’t yet received FDA approval.

Transgender men can take finasteride. But they should only use the medication under the guidance of a healthcare provider to ensure it aligns with their overall treatment goals and health needs.

Sometimes, finasteride is prescribed to trans men to treat hair loss (just as it is to cis men) because masculinizing hormone therapy (MHT) is associated with an increased risk of developing male pattern baldness.

But finasteride isn’t typically prescribed to trans men as part of hormone replacement therapy. Why? The drug may, in some cases, actually have feminizing side effects.

Research on Trans Men Hair Loss

In one survey, 43 percent of trans men who had testosterone-treated transmasculine therapy developed mild alopecia, and 31 percent developed moderate to severe alopecia.

Other research shows that the hair growth cycle can be interrupted in people who get MHT. The highest instance of baldness typically happens in the fourth year of MHT.

Finasteride can be very effective in treating hair loss in trans men.

In one small study, 10 transgender men were given 1 milligram (mg) of daily finasteride (the standard dose) for four and six months. All the patients improved one grade on the Norwood–Hamilton scale, a classification system used to measure the severity of male pattern baldness.

While finasteride is very effective for treating hair loss, there are a few things trans men should consider before taking it.

Finasteride Interaction with Testosterone Therapy

Trans men often take testosterone as part of their hormone therapy, which helps:

• Increase muscle mass

• Change fat distribution

• Improve body hair growth

Talk with your medical provider if you think finasteride may interact with how your hormone medications work.

Finasteride Side Effects

As with any medication, finasteride can have side effects. This includes sexual side effects like reduced sex drive (libido) and erectile dysfunction (ED).

That said, less than 2 percent of men experience sexual side effects, according to prescribing information from the FDA.

In very rare cases, finasteride may cause male breast development (gynecomastia).

→ Read: How to Reduce the Side Effects of Finasteride

Medical Supervision

Regular monitoring by a healthcare provider is crucial for tracking finasteride’s effects and making any necessary adjustments to your treatment plan.

It’s also worth noting that finasteride isn’t FDA-approved for people assigned female at birth due to its potential to cause birth defects (congenital disabilities). So, if a trans man wishes to get pregnant, it’s not a good option.

Transgender women may take finasteride to manage hair loss, reduce unwanted body and facial hair, and achieve other feminizing effects by lowering DHT levels.

Finasteride is sometimes used to treat hirsutism, a condition that causes unwanted male-pattern hair growth on the face, chest, or back in women. The medication might be offered to trans women to help decrease facial and body hair, though studies show it’s only “modestly effective” in reducing hair growth.

Considerations for Trans Women Taking Finasteride

Finasteride may be suggested as part of gender-affirming hormone therapy, particularly in the early stages of treatment. That said, there are a few unique considerations for trans women thinking about taking finasteride.

Combining Finasteride with Other Hormone Treatments

Transgender women undergoing hormone replacement therapy (HRT) may be on estrogen (oral estradiol) and possibly antiandrogens like spironolactone.

Finasteride can be used as part of this treatment plan to further reduce the effects of androgens. But research suggests that finasteride for transgender women is not all that effective once testosterone levels have already been lowered with standard treatment regimens, including estrogen with spironolactone or cyproterone acetate.

Some research actually suggests that the use of finasteride makes it challenging to achieve adequate testosterone suppression with estrogen. So keep that in mind.

Medical Supervision

It’s vital for transgender women to use finasteride under the supervision of a healthcare professional. Your provider can monitor your hormone levels and adjust your doses as needed.

Since transgender people have different goals, there isn’t one best hair growth treatment that works for everyone. Below are a few alternative hair loss treatments.

Minoxidil

We touched on minoxidil briefly in the context of beard growth, but here’s the deal for hair loss.

Minoxidil (generic for Rogaine^®) is a popular and effective hair loss medication that doesn’t affect hormones. The over-the-counter topical treatment can be a great option for those wanting to treat hair loss only in affected areas without hormonal changes.

We offer both a minoxidil foam and a minoxidil solution to encourage new hair growth. You can also find the ingredient in combination with finasteride in our topical finasteride & minoxidil spray.

Following a consultation with a licensed healthcare professional, an off-label prescription for oral minoxidil may also be available.

Spironolactone

Spironolactone is the most commonly used antiandrogen treatment for female pattern hair loss in the U.S. It’s frequently used by transgender women as part of GAHT.

By blocking male sex hormone receptors and reducing testosterone levels, spironolactone can contribute to the development of feminine characteristics, such as facial feminization and breast growth.

This medication isn’t usually recommended for men or trans men due to its feminizing side effects.

Saw Palmetto

If you’re interested in something similar to finasteride but plant-based, look to saw palmetto. There’s some evidence that the botanical ingredient partially blocks DHT.

You can find it in our thickening shampoo with saw palmetto.

There’s a lot to consider about the use of finasteride by transgender people. Here’s a quick recap on finasteride for trans men and women:

• Finasteride is part of a class of drugs called 5α-reductase inhibitors, which stop the conversion of testosterone to DHT. By treating pattern hair loss and reducing unwanted body hair, it can be a valuable component of gender-affirming therapy for trans men and trans women.

• Finasteride can and does affect hormones. It’s crucial for transgender individuals considering finasteride to do so under the guidance of a healthcare provider to monitor its effects, manage potential side effects, and adjust treatment plans as necessary.

• The best hair growth treatment varies based on personal goals and health conditions. So, transgender patients should consult healthcare professionals to explore options like minoxidil, finasteride, spironolactone, and other alternatives tailored to their specific needs.

→ Read: Finasteride Results Timeline: What to Expect

Find answers to frequently asked questions about finasteride for transgender people.

Can trans men grow facial hair on finasteride?

The hair follicles on the face aren’t as affected by DHT as those on the scalp. For this reason, finasteride typically doesn’t impact facial hair. Another FDA-approved medication for hair loss, topical minoxidil, generally offers better results for growing facial hair.

→ Learn more: Does Minoxidil Work for Beard Growth?

Does finasteride grow chest hair or body hair?

Finasteride is known to promote scalp hair. But, as with facial hair, the medication doesn’t affect body hair because body hair follicles aren’t nearly as sensitive to DHT. Research shows that finasteride is unlikely to have much effect on chest or body hair growth, but results vary.

Instead, testosterone is usually offered to trans men as part of gender-affirming care. The effects of testosterone can include increasing body and facial hair growth, as well as making existing hair thicker and coarser.

Does finasteride affect male breasts?

Development of male breast tissue (gynecomastia) is a very rare but possible side effect of finasteride. According to some research, only eight cases of gynecomastia have been reported with low-dose (1 mg daily) finasteride treatment since its FDA approval for androgenetic alopecia in 1997.

This might be under-reported, though. In clinical trials of finasteride, a very small percentage of men developed male breast cancer (male breast neoplasia), but this also occurred in several men in the placebo group. So, it’s unclear to what extent, if any, finasteride played a part in male breast cancer.

Still, if you notice breast tenderness or nipple discharge while taking finasteride, seek medical assistance as soon as possible.

→ Read next: Tyler’s Journey With Hair Loss and Hormone Therapy