Finasteride Side Effects: Trial Rates vs What Men Report
Finasteride side effects from the Propecia label's placebo-controlled trials, what the label adds from post-approval reports, and where the PFS debate stands.
By Julian Caraulani · Last updated
Safety
Below: the trial numbers, what the label says about reports after approval, what researchers have found on persistent symptoms, and where to ask a clinician. We do not give doses or tell anyone to start or stop a medicine.
Finasteride side effects in the trials (label table)
These are the drug-related side effects from three 12-month, placebo-controlled hair loss trials, as printed in Table 1 of the Propecia label. Generic finasteride tablets for hair loss carry the same data.
| Side effect | Propecia (N=945) | Placebo (N=934) | Source |
|---|---|---|---|
| Decreased libido | 1.8% | 1.3% | Propecia label, revised 8/2022 |
| Erectile dysfunction | 1.3% | 0.7% | Same label, Table 1 |
| Ejaculation disorder | 1.2% | 0.7% | Same label, Table 1 |
| Of which: decreased volume of ejaculate | 0.8% | 0.4% | Same label, Table 1 |
| Stopped because of a sexual side effect | 1.2% | 0.9% | Same label, Table 1 |
| Any of the above, year 1 | 3.8% | 2.1% | Same label, integrated analysis |
Two points from the same section matter as much as the table. The label says these effects went away "in men who discontinued therapy with PROPECIA due to these side effects and in most of those who continued therapy", and that the rate of each "decreased to ≤0.3% by the fifth year of treatment with PROPECIA" (DailyMed: Propecia label). Breast tenderness, breast enlargement and testicular pain were no more common than on placebo in those trials.
The label also covers a lab effect: finasteride lowers PSA, the prostate cancer blood test. It says "Any confirmed increase in PSA while on PROPECIA may signal the presence of prostate cancer and should be evaluated" (DailyMed: Propecia label). Tell whoever orders your PSA test that you take it.
What trials found vs what people report
Trials count side effects in a fixed group over a fixed time. Post-approval reports are different: anyone can file one, nobody knows how many men took the drug, and a report does not prove the drug caused the problem. The label says so itself, and then lists what was reported, including "sexual dysfunction that continued after discontinuation of treatment, including erectile dysfunction, libido disorders, ejaculation disorders, and orgasm disorders" and, under psychiatric effects, "depression, suicidal ideation and behavior" (DailyMed: Propecia label, postmarketing section). Male infertility, testicular pain and male breast cancer are on the same list.
Men who report symptoms that last after stopping often call it post-finasteride syndrome, or PFS. Researchers disagree about it, and we report both sides rather than pick one:
- A 2025 review describes PFS as "a condition eventually reported by men who have used finasteride" and concludes that treated men "could develop a plethora of non-neglectable physical and psychological symptoms identifying PFS" (Cilio et al., Int J Impot Res, PubMed).
- A 2026 follow-up of the large Prostate Cancer Prevention Trial linked about 15,000 men to Medicare records for a median of 20 years and found that "Of the 22 conditions potentially related to PFS, none had a statistically significant association with treatment arm" (Till et al., Urology, PubMed). That trial used the higher-strength prostate tablet, not the hair loss one.
- An analysis of FDA adverse event reports found reporting rose after 2012, "the year the PFS foundation formally propagated PFS awareness", and the authors attribute part of the excess to the nocebo effect (Gupta et al., J Dermatolog Treat, PubMed).
The FDA has also looked at compounded topical finasteride, which is not FDA-approved. It counted "32 cases reported to the FDA Adverse Event Reporting System between 2019 and 2024" and wrote that "Most of the reports FDA has received state the adverse events continued to persist after product discontinuation" (FDA alert on compounded topical finasteride).
What this means in practice: the trial rates are low, the reported persistent cases are real reports, and the science on cause is unsettled. If mood changes or sexual symptoms appear, the label and the FDA both point the same way: talk to the prescriber.
- FDA-approved and compounded
- No FDA warning letter found
- No state list published
Who should not handle finasteride
The label limits Propecia to men and lists pregnancy as a contraindication. Women who are or may be pregnant should not handle crushed or broken tablets, because of the risk to a male fetus. The tablets are coated; compounded sprays and gels are not, which the FDA flagged in the same alert.
What the videos show
Dermatologists, pharmacists and patients talk about finasteride side effects on YouTube. These are individual accounts and opinions, not evidence: a video cannot tell you how often a side effect happens. Use them to hear how men describe the experience, then check the numbers above. All of them are on our finasteride video hub.
Side Effects of FinasterideThe Hair Loss Show, October 2, 2019
Expectations of Taking FinasterideThe Hair Loss Show, September 23, 2020
Combining Finasteride and Minoxidil TherapiesThe Hair Loss Show, September 28, 2020
Videos belong to their channels; our summary is on each video's page. All 7 Finasteride videos.
Which programs let you message a clinician
If a side effect shows up, you want a fast answer from the person who prescribed. The table below shows which hair loss programs let you message a clinician after the visit, and how, from each program's own pages.
| Program | Message a clinician | Cost | Lowest price |
|---|---|---|---|
| Keeps | Yes: The plan lists 24/7 messaging access with a licensed medical provider among what you get. source, 2026-10-31 | Included | $14 |
| Ro | Yes: Free, unlimited follow-up messaging with a Ro-affiliated provider after you start treatment. source, 2026-10-31 | Included | $16 |
| GoodRx Care | Yes: You message your provider from the treatment subscription dashboard; a dose change or a long gap may require a new paid telehealth visit, and no messaging price is stated. source, 2026-10-31 | Not stated | $16 |
| Rex MD | Yes: Follow-ups are free once treatment starts; you message your assigned provider through the member portal any time. source, 2026-10-31 | Included | $18 |
| Happy Head | Yes: Unlimited dermatologist support to adjust treatment; the page calls it support rather than messaging and states no price for it. source, 2026-10-31 | Not stated | $18 |
| Tuyo Health | Yes: Monthly follow-ups are included and your doctor stays available to check in; the FAQ adds messaging with your provider on a secure platform. source, 2026-10-31 | Included | $18 |
| Strut Health | Yes: Free, unlimited follow-ups with a healthcare provider, who you can message from your account. source, 2026-10-31 | Included | $18.33 |
| Hims | Yes: You can message a provider with questions at any time, for free. source, 2026-10-31 | Included | $22 |
| Maximus | Yes: Every protocol includes 24/7 messaging with your care team at no additional cost. source, 2026-10-31 | Included | $24.99 |
| MangoRx | Yes: Unlimited access to licensed providers for any concerns, with ongoing provider support listed in the monthly plan; the page does not name the channel. source, 2026-10-31 | Included | $90 |
| Lemonaid Health | Yes: Messaging with clinical providers is included (stated on the oral minoxidil hair loss page; the ED page does not mention it). source, 2026-10-31 | Included | See review |
| PeterMD | Yes: Unlimited free consultations and 24/7 access to your medical team; the page says access and consults, not messaging by name. source, 2026-10-31 | Included | See review |
| Hone Health | Yes: Unlimited messaging with your care team, plus a clinician meeting every 3 months, as part of the membership. source, 2026-10-31 | Included in the paid Hone membership | See review |
| Rugiet | Yes: You can message your doctor anytime in the portal, and unlimited follow-ups with your doctor are included in the price. source, 2026-10-31 | Included | $99 |
| DudeMeds | Not found: No statement found on the site about messaging a clinician after starting treatment. | Not stated | See review |
From each program's own page, read 2026-10-31.
What it costs
Generic finasteride is cheap: from $0.83 a tablet at Strut Health, visit included, as checked October 31, 2026. Every program's monthly price is on our finasteride price page, the full breakdown is in our finasteride cost guide, and the overall ranking is on Best men's health programs.
Questions
FAQ
What are the most common finasteride side effects?
In the label's hair loss trials: decreased libido (1.8% vs 1.3% on placebo), erectile dysfunction (1.3% vs 0.7%) and ejaculation disorder (1.2% vs 0.7%). In all, 3.8% of men on the drug reported one or more of these in the first year, against 2.1% on placebo.
Do finasteride side effects go away?
In the trials, the label says they resolved in men who stopped and in most who kept taking it, and each fell to 0.3% or less by year five. After approval, the label added reports of sexual problems that continued after stopping. How often that happens is not known.
Is post-finasteride syndrome real?
It is disputed. Some reviews describe persistent sexual and psychological symptoms after stopping. A long Medicare follow-up of a large placebo-controlled trial found no link for 22 related conditions, and an analysis of FDA reports points to a nocebo effect. The reports themselves are real; the cause is what researchers argue about.
Does finasteride cause depression?
The current label lists depression, suicidal ideation and behavior among post-approval reports, which do not prove cause. If you notice mood changes, the prescriber is the person to call.
Does finasteride affect fertility?
The label lists male infertility and poor semen quality among post-approval reports, and notes improvement has been reported after stopping. Men planning a pregnancy should raise it with the prescriber.
Is topical finasteride safer?
There is no FDA-approved topical finasteride. Sprays and gels are compounded, and the FDA has received reports of the same side effects as the tablet, some persisting after stopping. Compounded products are not reviewed by the FDA for safety or quality.
Does finasteride affect a PSA test?
Yes. The label says finasteride lowers PSA, so a confirmed rise while taking it should be evaluated. Tell whoever orders the test.