Finasteride is one of the most effective treatments available for male pattern hair loss. It’s taken as a once-daily tablet and works by reducing levels of DHT, the hormone responsible for shrinking hair follicles.
But like any prescription medication, it’s important to understand the potential side effects before starting.
Here’s everything you need to know about finasteride side effects, from what’s common to what’s rare — and how to make an informed decision.
How Finasteride Works
Finasteride works by blocking an enzyme called 5-alpha-reductase, which converts testosterone into DHT (dihydrotestosterone). Lower DHT levels help prevent further hair loss and can even lead to regrowth in many cases — especially when used consistently over several months.
Is Finasteride Safe?
Yes — for most men, finasteride is very well tolerated. It has been approved for hair loss treatment for over two decades and is used by millions worldwide. But as with any medication, a small percentage of users may experience side effects.
Common Side Effects (Rare but Possible)
Less than 2–3% of users may experience mild side effects. These include:
- Reduced libido (lower sex drive)
- Erectile dysfunction
- Ejaculation issues or reduced semen volume
It’s worth noting that these side effects are usually temporary and tend to resolve either with continued use or once the medication is stopped. Many men experience no issues at all.
Less Common Side Effects
In very rare cases, users may report:
- Mood changes, such as anxiety or low mood
- Breast tenderness or swelling
- Testicular discomfort
If you notice anything unusual or persistent, it’s important to speak to a healthcare provider. At Follicle, our clinicians assess your suitability for finasteride before prescribing, and we’re always here to support you with ongoing guidance.
Post-Finasteride Syndrome: Should You Be Concerned?
You may have heard of something called post-finasteride syndrome (PFS), a term used to describe persistent side effects after stopping the medication. While it’s received attention online, PFS is not currently recognised as an official medical diagnosis, and studies show the vast majority of men experience no long-term issues.
How to Reduce Risk of Side Effects
- Stick to the prescribed dose (1mg daily).
- Take it consistently at the same time each day.
- Communicate with your provider if you notice any side effects — don’t suffer in silence.
The Bottom Line
Finasteride remains one of the most powerful tools we have for fighting male pattern hair loss. Side effects are rare, often reversible, and occur in a small percentage of users. If you’re considering treatment, the best next step is to complete our free online consultation — our clinicians will help determine if finasteride is the right option for you.
With the right guidance and consistent use, you could be well on your way to thicker, stronger hair — with confidence in your treatment plan.
