Finasteride: What It Is, How It Works, and What to Expect

Finasteride is a pill you take once a day to treat two common problems: male pattern hair loss and an enlarged prostate (benign prostatic hyperplasia, or BPH). It belongs to a group called 5‑alpha‑reductase inhibitors, which means it stops the enzyme that turns testosterone into dihydrotestosterone (DHT). Lower DHT levels slow hair thinning on the scalp and can shrink the prostate, easing bathroom trips.

Common Uses of Finasteride

Most men hear about finasteride for hair loss under the brand name Propecia (1 mg). In that dose, the drug helps keep hair on the crown and front of the head from falling out. It doesn’t grow new hair, but it can stop the balding process and keep existing hair thicker.

The same medication, but at a higher dose of 5 mg, is sold as Proscar and is prescribed for BPH. Men taking the 5 mg dose often notice fewer nighttime bathroom trips, a weaker stream, and less urgency. Some doctors also use the 5 mg version off‑label for severe hair loss when lower doses aren’t enough.

Dosage, Side Effects, and Safety Tips

For hair loss, the usual dose is 1 mg taken at the same time each day. For BPH, it’s 5 mg once daily, sometimes split into two doses. Take the tablet with water; food doesn’t change how it works.

Most users tolerate finasteride well, but a small share experience side effects. The most reported issues are a drop in sexual desire, trouble getting an erection, or a smaller amount of semen. These symptoms often improve after a few weeks or months, and many disappear if you stop the drug.

Other possible effects include breast tenderness, rash, or mood changes. If you notice depression, anxiety, or persistent sexual problems, talk to your doctor right away. Women who are pregnant or may become pregnant should never handle crushed or broken tablets, because the drug can harm a male fetus.

Before starting finasteride, let your doctor know about any liver disease, prostate cancer, or medications you’re already using. Some drugs, like certain antifungals and antibiotics, can raise finasteride levels and increase side‑effect risk.

Blood tests aren’t required for every visit, but many doctors check prostate‑specific antigen (PSA) levels before you begin treatment for BPH. Finasteride can lower PSA, so the lab needs to know you’re on the drug to interpret the results correctly.

How long should you stay on finasteride? For hair loss, you’ll usually need to keep taking it indefinitely. If you stop, any benefits you gained will slowly fade over several months, and hair loss can resume. For BPH, some men stay on the medication for years, while others use it temporarily to reduce prostate size before surgery.

To get the best results, combine finasteride with a healthy lifestyle. A diet rich in protein, iron, and vitamins, plus regular exercise, supports overall hormone balance and can enhance hair‑preserving effects.

Bottom line: finasteride is a simple, once‑daily pill that can make a real difference for men dealing with hair loss or an enlarged prostate. Knowing the correct dose, watching for side effects, and staying in touch with your doctor will help you use it safely and effectively.