Male pattern hair loss (MPHL) affects more than 50% of men in their 40s¹, and female pattern hair loss (FPHL) affects approximately 40% of women by age 50², making it a prevalent concern. There are two popular oral medications to consider regarding hair loss: spironolactone and finasteride. While they share the same goal of combating hair loss, the two medications vary in effectiveness and suitability by sex.

Learn more about the characteristics, effectiveness, and potential side effects of spironolactone and finasteride so that you, along with your licensed medical provider, can make a confident and educated decision on how to treat hair loss.

What is spironolactone?

Spironolactone (generic Aldactone®) is a synthetic aldosterone receptor antagonist that can stimulate hair growth.³ Aldosterone is a naturally occurring hormone and when the body produces too much (hyperaldosteronism), it can lead to hair loss.⁴

Spironolactone is commonly prescribed for women experiencing hair loss because other oral hair loss medications are not approved for women. Finasteride, for example, is not approved for use by women due to the potential for fetal abnormalities⁵ including a high risk of birth defects.

In a study from the Journal of the American Academy of Dermatology, 74.3% of participants who experience female pattern hair loss reported stabilization or improvement of their condition with the use of spironolactone.⁶

Studies have also shown spironolactone to be effective in the treatment of acne. Users have reported anywhere from 50% to 100% reduction in acne.⁷

Dosing for spironolactone for hair loss in women is 100mg to 400mg per day, depending on your medical provider’s advice.⁸

What is finasteride?

Finasteride (generic Propecia®) is an oral prescription medication primarily used to treat male pattern baldness. Like spironolactone, finasteride treats androgenetic alopecia or hair loss caused by too much of an androgen hormone in the body. It works by blocking the conversion of testosterone into DHT, the androgen responsible for male pattern hair loss.⁹

Finasteride is also prescribed to treat the symptoms of a prostate condition called benign prostatic hyperplasia (BPH).

Common dosing for finasteride to treat male pattern baldness is 1mg per day.¹⁰

Finasteride is not FDA-approved for use by women and is forbidden in pregnant women due to a high risk of birth defects.¹¹

What’s the difference between spironolactone and finasteride?

Spironolactone and finasteride are oral medications commonly prescribed for hair loss or androgenetic alopecia. Both medications interact with androgen hormones in the body to prevent or stop hair loss but affect hormones differently. This is why it is recommended that only women take spironolactone and only males take finasteride.

For women, studies have shown the best results when taking spironolactone for at least six months.¹² Men can also expect noticeable results from finasteride in about six months.¹³

Spironolactone vs. Finasteride Comparison

What are the side effects of spironolactone and finasteride?

Possible side effects of spironolactone for women include:¹⁴

• Heartburn

• Sexual dysfunction

• Leg cramps

• Sores, welts, or blisters

• Stomach upset

• Swelling of the breasts or breast soreness

• Fatigue

• Constipation

• Dizziness or faintness

Possible side effects of finasteride for men include:¹⁵

• Sexual dysfunction and decreased desire

• Pain in the testicles

• Depression

Talk to your provider about how to deal with or minimize any unpleasant side effects of spironolactone and finasteride.

Is spironolactone or finasteride available over the counter?

Both spironolactone¹⁶ and finasteride¹⁷ require a prescription and are not available over the counter. You can get a prescription for either spironolactone or finasteride online, however, at telehealth providers like RedBox Rx.

As mentioned previously, spironolactone is approved for use in women and finasteride is only approved for use in men.

How RedBox Rx can help

RedBox Rx makes receiving medication treatment for hair loss easy and affordable.

Benefits of RedBox Rx include:

• Transparent, affordable, flat rates for hair loss prescriptions starting at $10/month.

• FREE consultations with a U.S. licensed medical provider.

• No insurance required. FSA and HSA eligible.

• FREE shipping directly to you. Monthly and quarterly subscription options available.

Get started on your hair loss treatment journey with our short online assessment for men’s hair loss or women’s hair loss.