Why Shouldn’t Women Use Finasteride?

Why Shouldn’t Women Use Finasteride?

Table of Contents

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I. What is Finasteride?

II. How Does Finasteride Work?

III. Why Can’t Women Take Finasteride?

IV. Finasteride: Off-Label Use for Women

V. Conclusion

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Although hair loss is often thought of as a "male problem," many women struggle with thinning hair and bald spots, too. In fact, it's estimated that one-third of women will deal with noticeable hair loss at some point in their lives. And for women after menopause, that number jumps to a whopping two-thirds. ¹

With hair loss being so common in women, you may be wondering why some treatments aimed at men aren't approved for women too. One notable example is finasteride - a medication commonly prescribed to men that has proven results for male pattern baldness.

In this article we’ll break down the mystery surrounding finasteride. We will discuss what it is, how it works, and why it is not recommended for all women.

What is Finasteride?

Finasteride is a once-daily tablet that was FDA-approved in 1992 to treat male pattern baldness. It works by blocking the production of DHT, a hormone that contributes to hair loss in men. ²

When taken daily, finasteride can lead to hair regrowth within three months. However, you need to keep taking finasteride long-term to maintain the benefits. If you stop taking finasteride, any hair you've regrown or protected from loss will start to thin and fall out again within 12 months. ²

How Does Finasteride Work?

Finasteride works by targeting and inhibiting an enzyme known as Type II 5a-reductase. This enzyme plays an important role in converting testosterone, the male sex hormone, into dihydrotestosterone (DHT). ³

During fetal development and puberty, DHT is crucial for the development of male sexual characteristics. However, later in life, DHT can lead to male pattern baldness in genetically susceptible individuals. ³

In men with male pattern baldness, the balding areas of the scalp contain hair follicles that have been weakened over time by exposure to DHT. The scalp tissue in these areas also shows higher levels of DHT compared to hairy areas of the scalp. By blocking the 5a-reductase enzyme, finasteride reduces DHT levels in both the scalp and the bloodstream. This helps disrupt the key mechanism driving male pattern baldness. ²

Why Can’t Women Take Finasteride?

Finasteride is not FDA-approved for use in women, and for good reason. This medication may cause birth defects if taken during pregnancy. That's why it is typically not prescribed for women of childbearing age. ¹

But how exactly does finasteride affect a developing baby?

Finasteride works by blocking an enzyme that converts testosterone to dihydrotestosterone (DHT). DHT is the culprit behind male pattern baldness, but it also plays a crucial role in the development of male genitalia before birth. Animal studies found that male fetuses exposed to finasteride developed abnormal external genitalia. ¹

The risks don't end with finasteride consumption. According to the FDA, even handling crushed or broken finasteride tablets can be dangerous for pregnant women or women who may become pregnant. In addition, women can be exposed to finasteride through a partner's semen if he is taking the medication. ¹

The potential for birth defects is why finasteride is not prescribed for women unless they are absolutely certain they cannot get pregnant. Fortunately, there are other hair loss treatment options, such as minoxidil, that don’t present these same risks.

Finasteride: Off-Label Use for Women

Despite the risks, finasteride has been prescribed off-label to some women to treat female pattern baldness. ⁴ Off-label means the drug is being used for something other than its FDA-approved purpose, which for finasteride is treating hair loss in men.

Several studies have examined finasteride's effects in women, with promising but limited results. It is unclear exactly why finasteride improves female hair loss. And testing is restricted because of the danger to unborn babies if taken while pregnant. ⁴

We’ve outlined the results of some notable studies below:

• Finasteride 1 mg daily: A 12-month study gave 137 post-menopausal women 1 mg of finasteride daily. Unfortunately, it didn't improve hair loss, growth, or appearance.

• Finasteride 2.5 mg daily with an oral contraceptive: A 12-month study on 37 pre-menopausal women combined finasteride 2.5 mg per day with an oral contraceptive. Participants had increased hair density, but researchers weren't sure if the finasteride or contraceptive was responsible.

• Finasteride 5 mg daily: In a study involving 87 pre- and post-menopausal women over 12 months, participants taking finasteride 5 mg daily experienced positive outcomes. Nearly 19% saw increased hair density, and 9.4% had thicker hair. However, some women also reported side effects like headaches, irregular periods, dizziness, and increased body hair. ⁴

Overall, the studies suggest that a higher dose of finasteride may be more effective in treating female pattern hair loss. However, researchers caution against its use in women of childbearing age due to the potential risk of birth defects. ⁴

Conclusion

Research on the benefits of finasteride for women is still in its early stages. This is largely due to concerns about potential birth defects if used by women who are or may become pregnant.

Current studies, though limited, indicate higher doses of finasteride may help some women regrow hair and slow further thinning, which is why doctors may prescribe finasteride off-label. However, due to the risks for male fetuses, experts advise that finasteride only be used by postmenopausal women. Many premenopausal women opt for safer alternatives like minoxidil to treat thinning hair.