From the Guidelines
Yes, finasteride has been linked to serious side effects, including sexual dysfunction, which can occur in 2-3% of users, as reported in the study by 1.
Key Side Effects
- Decreased libido
- Erectile dysfunction
- Ejaculation disorders
- Gynecomastia
- Decreased ejaculate volume These side effects are due to finasteride's mechanism of blocking the conversion of testosterone to dihydrotestosterone (DHT), which affects not only hair follicles and the prostate but also sexual function and neurosteroid production in the brain.
Importance of Discussion with Healthcare Provider
Anyone considering finasteride should discuss these risks with their healthcare provider, especially if they have a history of depression or sexual dysfunction, and report any side effects promptly if they occur during treatment, as suggested by the study 1.
Post-Finasteride Syndrome (PFS)
More concerning is Post-Finasteride Syndrome (PFS), where these sexual side effects persist even after stopping the medication, sometimes for months or years, although the exact incidence and cause of PFS are not well understood and require further research, as noted in the study 1.
Other Reported Side Effects
Other reported side effects include depression, anxiety, cognitive issues, and rarely, suicidal thoughts, as well as concerns about potential links to male breast cancer, though this remains rare, as reported in the study 1.
Conclusion Not Provided
As per the guidelines, no conclusion section is provided, and the answer focuses on the key points related to the question about finasteride's side effects.
From the FDA Drug Label
The most frequently reported adverse reactions were related to sexual function. 3.7% (57 patients) treated with finasteride tablets and 2. 1% (32 patients) treated with placebo discontinued therapy as a result of adverse reactions related to sexual function, which are the most frequently reported adverse reactions The incidence of Gleason score 8 to 10 prostate cancer was higher in men treated with finasteride (1.8%) than in those treated with placebo (1. 1%) During the 4- to 6-year placebo- and comparator-controlled MTOPS study that enrolled 3,047 men, there were 4 cases of breast cancer in men treated with finasteride but no cases in men not treated with finasteride The following additional adverse events have been reported in postmarketing experience with finasteride tablets:
- hypersensitivity reactions, such as pruritus, urticaria, and angioedema (including swelling of the lips, tongue, throat, and face)
- testicular pain -hematospermia
- sexual dysfunction that continued after discontinuation of treatment, including erectile dysfunction, decreased libido and ejaculation disorders (e. g. reduced ejaculate volume).
- male infertility and/or poor seminal quality were reported rarely in men taking finasteride tablets for the treatment of BPH.
- depression
- male breast cancer
- orgasm disorders
Serious side effects linked to finasteride include:
- Increased risk of prostate cancer with a higher Gleason score
- Breast cancer in men
- Hypersensitivity reactions, such as angioedema
- Sexual dysfunction that continues after discontinuation of treatment, including erectile dysfunction, decreased libido, and ejaculation disorders
- Male infertility and/or poor seminal quality
- Depression
- Orgasm disorders 2 2
From the Research
Serious Side Effects Linked to Finasteride
- Finasteride has been associated with various serious side effects, including sexual dysfunction, mood alteration, and cognitive complaints 3.
- Post-finasteride syndrome (PFS) is a condition characterized by persistent side effects, such as low libido, erectile dysfunction, and depression, that can occur despite drug withdrawal 3, 4.
- Studies have reported that finasteride can increase the risk of erectile dysfunction (ED), with some studies suggesting that the risk may be higher in patients with benign prostatic hyperplasia (BPH) than in those with male androgenetic alopecia (MAA) 5.
- Persistent sexual side effects have been reported to continue for many months or years after discontinuation of finasteride, with some studies suggesting that these effects may be permanent 4, 6.
- Other serious side effects linked to finasteride include decreased libido, ejaculate problems, and loss of libido, as well as changes in cognition, genital sensation, and ejaculate quality 3, 4, 7.
Prevalence of Serious Side Effects
- The prevalence of serious side effects linked to finasteride varies widely, with some studies reporting that up to 15.8% of men may experience sexual side effects, such as erectile dysfunction and decreased libido 7.
- A systematic review of adverse effects and safety of 5-alpha reductase inhibitors, including finasteride, found that sexual effects, including erectile dysfunction and decreased libido, were reported in as many as 3.4 to 15.8% of men 7.
- Another study found that 96% of subjects with persistent sexual side effects associated with finasteride continued to experience these effects after 9-16 months, with 89% meeting the definition of sexual dysfunction 4.
Regulatory Actions
- National agencies, such as the Swedish Medical Products Agency, the Medicines and Healthcare Products Regulatory Agency of the UK, and the US Food and Drug Administration, have required the inclusion of multiple persistent side effects within the finasteride labels 3.
- The US National Institutes of Health has added a link for post-finasteride syndrome to its Genetic and Rare Disease Information Center, highlighting the potential risks associated with finasteride use 7.