Tamsulosin vs Finasteride

Tamsulosin provides rapid symptom improvement, often within days to weeks. It effectively reduces bothersome urinary symptoms like weak stream, frequency, and urgency. However, it does not shrink the prostate or reduce the long-term risk of urinary retention or the need for surgery.

Finasteride works more slowly, taking 3-6 months for noticeable improvement. It reduces prostate volume by approximately 20-25% over 6-12 months. The landmark MTOPS trial showed that finasteride significantly reduces the risk of acute urinary retention and need for BPH surgery — benefits that tamsulosin alone does not provide.

For men with significantly enlarged prostates (>40 grams), combination therapy with both tamsulosin and finasteride is superior to either drug alone, as shown in the CombAT and MTOPS trials.

Tamsulosin's most common side effects are dizziness (especially when standing — orthostatic hypotension), abnormal ejaculation (retrograde ejaculation in 8-18% of patients), nasal congestion, and headache. It can also cause intraoperative floppy iris syndrome during cataract surgery — inform your eye surgeon if you take or have taken tamsulosin.

Finasteride's notable side effects are sexual: decreased libido (5-6%), erectile dysfunction (5-8%), and decreased ejaculate volume. These effects resolve in most men after stopping the drug. Finasteride also lowers PSA levels by approximately 50%, which must be accounted for during prostate cancer screening.

Finasteride carries a warning about a possible small increased risk of high-grade prostate cancer, based on the PCPT trial, though this finding remains debated.

Both tamsulosin and finasteride are available as affordable generics. Generic tamsulosin costs approximately $5-$20 per month, and generic finasteride (5 mg for BPH) costs approximately $5-$15 per month. Both are among the most cost-effective treatments for BPH.

Combination therapy increases monthly medication costs but is still very affordable with generics.

Both medications are taken once daily. Tamsulosin is typically taken 30 minutes after the same meal each day. Finasteride can be taken at any time with or without food. Neither requires regular blood tests or monitoring visits beyond routine urological care.

Women who are or may become pregnant should not handle crushed or broken finasteride tablets, as the drug can be absorbed through the skin and may cause birth defects in male fetuses.

For mild to moderate BPH symptoms with a normal-sized prostate, tamsulosin is usually the first choice because it works quickly and provides immediate symptom relief.

For men with significantly enlarged prostates, finasteride (alone or combined with tamsulosin) may be more appropriate because it addresses the underlying prostate growth and reduces long-term risks of retention and surgery.

If sexual side effects are a major concern, tamsulosin has a different side effect profile (ejaculatory changes rather than libido/erectile effects). Your urologist will recommend treatment based on your prostate size, symptom severity, and individual risk factors.