Finasteride side effects, from the 1 mg label
The Propecia label, finasteride 1 mg for male pattern hair loss in men only, lists decreased libido, erectile dysfunction, and ejaculation disorder as the drug-related reactions reported in 1% or more of patients and more often than placebo. That is the label. It is not a reason to hide the medicine, and it is not a reason to ignore it.
The numbers the label prints
Position 1 on 2026-10-16 is a GoodRx page. These percentages are from the 2012 Propecia prescribing information we opened, year-1 trials.
| Drug-related reaction, year 1 | Propecia 1 mg (n=945) | Placebo (n=934) |
|---|---|---|
| Decreased libido | 1.8% | 1.3% |
| Erectile dysfunction | 1.3% | 0.7% |
| Ejaculation disorder | 1.2% | 0.7% |
The label also says 5-alpha-reductase inhibitors may increase the risk of high-grade prostate cancer. In the Prostate Cancer Prevention Trial, finasteride 5 mg (five times the hair dose) had Gleason 8-10 cancer in 1.8% versus 1.1% on placebo, in men 55 and older with a normal exam and PSA of 3.0 ng/mL or less at the start. Propecia also lowers PSA. A rise from your lowest PSA on treatment needs a look, even if the number is still in a normal range.
The label is for men only. It is contraindicated in pregnancy. Women who are or may be pregnant should not handle crushed or broken tablets. Benefit, if it comes, generally takes three months or more of daily use. Stopping reverses the effect within 12 months.
A compounded oral tablet is not the Propecia tablet. The clinician decides. The combination page is finasteride and minoxidil.
References
Opened 2026-10-16. A number that was not in these files is not on this page.
- FDA label: Propecia (finasteride) tablets, revised April 2012. 1 mg once daily. Sexual adverse reactions. PSA. High-grade prostate cancer warning.
- Who ranks for finasteride side effects: GoodRx. We used the label, not their summary.
About Mendoxa
- Mendoxa serves 49 U.S. states. Not available in California.
- A licensed clinician can say no. A prescription is not automatic.
- When a prescription is issued, Rush Pharmacy fulfills it.
- A compounded medicine is not an FDA-approved finished product.
- The price is shown in the intake, not on this page.