Propecia (Finasteride)

Propecia (finasteride) is a prescription drug used to treat male pattern hair loss (androgenetic alopecia) in adult men. As a 5a-reductase inhibitor, it works by blocking the enzyme that converts testosterone into dihydrotestosterone (DHT). DHT is a hormone that can shrink hair follicles and lead to thinning hair in men who are prone to balding. Taking a 1 mg tablet once daily may help slow hair loss and may regrow some hair on the top and front-middle part of the scalp.

Directions

Take Propecia by mouth as one 1 mg tablet once per day, with or without food. Take it at the same time each day for best results. It usually takes at least 3 months to notice changes in hair growth, and the full effect may take longer. If you stop taking it, the hair benefits usually begin to fade within 12 months. Do not break, crush, or take more tablets than prescribed. Use Propecia as prescribed by a healthcare provider.

Ingredients

The active ingredient in Propecia is finasteride. The inactive ingredients may include lactose monohydrate, microcrystalline cellulose, pregelatinized starch, sodium starch glycolate, hydroxypropyl methylcellulose (hypromellose), hydroxypropyl cellulose, titanium dioxide, magnesium stearate, talc, docusate sodium, yellow ferric oxide, and red ferric oxide.

Cautions

Before using this medication, you may want to consult a healthcare provider about the following:

• Any existing health conditions
• Any allergies
• A list of all medications currently being taken

Propecia is for use in adult men only. It is not approved for women or for children, and women who are or could become pregnant should avoid handling crushed or broken tablets because finasteride can be absorbed through the skin and may harm a developing male fetus.

Propecia can lower the level of prostate-specific antigen (PSA) in the blood by about 50%. Tell your healthcare provider you are taking Propecia before any PSA test.

5-alpha reductase inhibitors such as finasteride may slightly increase the risk of developing high-grade prostate cancer. Discuss prostate cancer screening and overall risk with your healthcare provider, especially during long-term use.

Sexual side effects such as decreased sex drive, erectile dysfunction, or reduced ejaculation can occur with Propecia. In most men these effects go away after stopping the medication, but in some cases they have been reported to continue after treatment is discontinued.

Mood changes, including depression and rare reports of suicidal thoughts or behavior, have been reported in men taking finasteride. Tell your healthcare provider if you notice new or worsening depression, anxiety, or thoughts of self-harm.

Propecia may affect male fertility and semen quality in some men. If you and your partner are trying to conceive or have concerns about fertility, talk to a healthcare provider before starting finasteride.

Watch for breast changes such as new lumps, pain, tenderness, or nipple discharge. In rare cases, male breast cancer has been reported in men taking finasteride.

People with liver problems may need closer monitoring during treatment because finasteride is processed by the liver.

Propecia is not meant for emergency or short-term use. Hair regrowth depends on consistent treatment, so do not skip doses or stop suddenly without speaking to your provider first.

Contraindications

Avoid taking or using this medication if any of the following apply:

• Pregnancy, as finasteride may cause harm to an unborn baby.
• A known allergy or hypersensitivity to finasteride or any of the inactive ingredients in Propecia.

Side Effects

Common side effects of Propecia include:

• Decreased sex drive (libido)
• Erectile dysfunction (trouble getting or keeping an erection)
• Ejaculation disorder, including reduced ejaculate volume
• Breast tenderness or enlargement
• Skin rash, itching, or hives
• Testicular pain

Get medical help if you have signs of a serious allergic reaction such as swelling of the lips, tongue, throat, or face, trouble breathing, or a severe rash.

Other serious problems that have been reported include sexual side effects that continue after stopping the medication (including erectile dysfunction, low libido, ejaculation, and orgasm problems), male infertility or reduced semen quality, blood in the semen (hematospermia), depression, suicidal thoughts or behavior, and male breast cancer.

References

• Propecia Highlights of Prescribing Information. Jersey City, NJ: Organon LLC; 2023.
• Propecia Drug Label Information. Jersey City, NJ: Organon LLC; 2023.