Finasteride Tablets Side Effects: Onset & Duration
Finasteride is a prescription medication used to treat male pattern hair loss and enlarged prostate. Available in 1mg and 5mg tablets.
Key Takeaways
- Common side effects: Sexual dysfunction (e.g., erectile dysfunction), decreased libido, breast tenderness
- Onset: Typically within 1-3 months of starting treatment
- Duration: Most resolve within weeks of stopping; some cases report persistent effects
- Rare but serious: Depression, allergic reactions, male breast cancer
- Contraindications: Not for use by women or children
Common Side Effects of Finasteride
Finasteride works by inhibiting the conversion of testosterone to dihydrotestosterone (DHT), which can lead to:
Sexual Side Effects (affect 1-10% of users)
- Erectile dysfunction
- Decreased libido
- Reduced semen volume
- Difficulty achieving orgasm
Other Common Effects
- Breast tenderness or enlargement (gynaecomastia)
- Skin rash or itching
- Testicular pain
Note: These effects are usually dose-dependent and may improve with continued use.
When Do Finasteride Side Effects Start?
| Side Effect | Typical Onset |
|---|---|
| Sexual dysfunction | 1-3 months after starting |
| Decreased libido | Within first 6 months |
| Breast tenderness | 3-12 months |
How Long Do Finasteride Side Effects Last?
After Stopping Treatment
- Most users: Side effects resolve within weeks to months
- Persistent cases: Some reports of symptoms lasting years (Post-Finasteride Syndrome)
Recovery Timeline
| Symptom | Average Resolution Time |
|---|---|
| Erectile dysfunction | 4-12 weeks |
| Low libido | 3-6 months |
| Breast changes | May require medical intervention |
Serious Side Effects
- Allergic reactions (swelling, difficulty breathing)
- Lumps or pain in breast tissue
- Severe depression or suicidal thoughts
Rare but Important
- Male breast cancer (reported in long-term users)
- Testicular pain or changes
- High-grade prostate cancer risk (controversial)
Managing Finasteride Side Effects
What to Do
- Monitor symptoms: Keep a diary of any changes
- Dose adjustment: Some men tolerate 0.5mg daily
- Consult your GP: Before stopping or changing treatment
When to Stop
- Persistent sexual dysfunction >3 months
- Any signs of depression or mood changes
- Breast changes that don't resolve
Frequently Asked Questions
Do Finasteride side effects go away if I continue taking it?
Some users report adaptation within 6-12 months, but persistent symptoms warrant discontinuation. Always consult your doctor.
Can Finasteride cause permanent erectile dysfunction?
While rare, some cases of persistent sexual dysfunction have been reported even after stopping Finasteride (Post-Finasteride Syndrome).
Is there an alternative to Finasteride with fewer side effects?
Minoxidil (topical treatment) or low-level laser therapy may be options. Discuss alternatives with your GP.
Can women use Finasteride for hair loss?
No. Finasteride is contraindicated in women of childbearing potential due to risk of foetal abnormalities.
Does alcohol make Finasteride side effects worse?
Alcohol doesn't directly interact with Finasteride but may exacerbate side effects like dizziness or depression.
Considering Finasteride for Hair Loss?
If you're experiencing male pattern hair loss, our UK-registered doctors can help determine if Finasteride is appropriate for your condition through a confidential online consultation.
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Medical Content Manager
Nabeel is a co-founder and medical content manager of Chemist Doctor. He works closely with our medical team to ensure the information is accurate and up-to-date.
Medical Doctor
Dr. Feroz is a GMC-registered doctor and a medical reviewer at Chemist Doctor. He oversees acute condition and urgent care guidance.
Medical Director
Usman is a co-founder and medical director of Chemist Doctor. He leads the organisation's strategic vision, bridging clinical and operational priorities.
Review Date: 27 October 2025
Next Review: 30 April 2026
Published on: 27 October 2025
Last Updated: 28 October 2025
