Dutasteride
3 medicines
Dutasteride is a capsule that lowers DHT to shrink an enlarged prostate and treat hair loss; women who are or may be pregnant must never handle broken or leaking capsules, since contact can harm a male fetus.
Key facts
- Dutasteride (sold as Avodart, and combined with tamsulosin as Jalyn) blocks the enzyme that converts testosterone to DHT, treating an enlarged prostate and, at a lower dose, male pattern hair loss.
- Benefits build slowly: prostate symptoms usually improve over 3 to 6 months, and hair regrowth takes a similar time.
- Women who are or may become pregnant must never handle broken or leaking capsules. Skin contact can affect a male fetus's genital development; intact capsules are safe to handle.
- Dutasteride has a long half-life and stays in the blood for months after the last dose. Men should not donate blood for 6 months after stopping, in case it is given to a pregnant recipient.
What dutasteride treats
Dutasteride treats benign prostatic hyperplasia (BPH), a non-cancerous enlargement of the prostate that causes a weak urine stream, frequent urination and incomplete emptying. It reduces the risk of acute urinary retention and the need for prostate surgery, and it is combined with tamsulosin (Jalyn) for men who need faster symptom relief alongside prostate shrinkage. It is also used, at a lower dose, for male pattern hair loss.
How dutasteride works
Dutasteride blocks 5-alpha-reductase, the enzyme that converts testosterone into dihydrotestosterone (DHT). Lower DHT levels let an enlarged prostate shrink gradually, relieving pressure on the urethra, and let scalp hair follicles stay in their growth phase for longer.
Before you take it
- Women who are pregnant or could become pregnant must never handle broken or leaking capsules; even skin absorption can pose a risk to a developing male fetus.
- Tell your prescriber about liver disease, since dutasteride is processed by the liver and levels can build up.
- Dutasteride lowers PSA readings by about half; tell any doctor ordering a PSA test that you take it.
- Certain medicines that affect liver enzymes (some antifungals, some HIV medicines, verapamil) can raise dutasteride levels; mention these to your prescriber.
Side effects
Common effects include reduced sex drive, erectile difficulty, less semen at ejaculation, and mild breast tenderness or swelling.
Stop and seek urgent medical care for any of these:
- Breast lumps, pain or nipple discharge.
- Signs of an allergic reaction: swelling, hives, or trouble breathing.
- Persistent testicular pain.
Safety essentials
- Keep capsules intact and out of reach of women who are pregnant or could become pregnant. Broken or leaking capsules must not touch their skin, because of the risk to a male fetus.
- Dutasteride stays in your system for months. Do not donate blood for 6 months after your last dose, and discuss timing with your prescriber if your partner is trying to conceive.
- Give treatment time: it takes 3 to 6 months to judge whether it is working, for both prostate and hair-loss use.
- Mention dutasteride before any PSA prostate-cancer screening test, since it lowers the reading.
This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.