If you use finasteride for hair loss, or are thinking about it, you might have come across the term post-finasteride syndrome (PFS). PFS is a collection of persistent side effects that some men report after stopping finasteride, including sexual dysfunction, mood changes, and fatigue.
However, PFS isn't recognised as an official medical condition by most health organisations and experts haven’t agreed on a main cause. Here’s what we do know about post-finasteride syndrome so far.
What is post-finasteride syndrome (PFS)?
Finasteride is a medication commonly prescribed to treat male pattern baldness and benign prostatic hyperplasia (an enlarged prostate). Post-finasteride syndrome refers to a range of persistent side effects that some men experience after they stop taking finasteride. The exact cause of PFS is unknown and debated among experts. Some research suggests finasteride may reduce concentrations of neurosteroids in the brain (the chemicals important for mood, memory, and anxiety regulation) which could potentially explain some of the reported symptoms.
While patients report a relatively consistent set of symptoms, the condition isn't officially recognised by major medical bodies as high-quality research is still limited.
Post-finasteride syndrome symptoms
PFS symptoms are similar to finasteride side effects that can occur during treatment. The key difference is that most side effects resolve when you stop the medication, while PFS symptoms persist after stopping.
Reported post-finasteride syndrome symptoms vary widely among individuals and may include:
Sexual
- Decreased or complete loss of libido
- Erectile dysfunction
- Loss of "morning wood" and spontaneous erections
- Sexual anhedonia (loss of pleasure from sexual activity or orgasm)
- Reduced ejaculatory volume and force
- Peyronie's disease (penile curvature, shrinkage, or numbness)
- Testicular shrinkage or numbness
Physical
- Gynaecomastia (breast enlargement or tenderness)
- Chronic fatigue and low energy
- Muscle issues (pain, weakness, cramps, stiffness, or spasms)
- Rhabdomyolysis (muscle breakdown)
- Dry, thinning skin with reduced oil production
- Tinnitus (ringing in the ears)
- Vision problems (damage to the optic nerve or retina)
- Weight gain and increased body fat
- Decreased body temperature
- Metabolic changes (altered cholesterol, blood sugar, and triglycerides)
Neurological & mood
- Depression and anxiety
- Suicidal thoughts
- Memory problems
- Cognitive impairment (slowed thinking, poor problem-solving)
- Insomnia or sleep apnoea
- Anhedonia (emotional flatness)
Mental health symptoms and PFS
Finasteride works by blocking an enzyme called 5-alpha reductase, which converts testosterone into dihydrotestosterone (DHT). DHT is the hormone responsible for shrinking hair follicles, so reducing it can slow or stop hair loss.
However, one study found that men with ongoing sexual symptoms after finasteride didn't have low testosterone or reduced hormone activity. Instead, mood changes and brain scans showed patterns similar to depression, suggesting the effects may be more about the brain and mood than hormones.
Some research also suggests that having a pre-existing mental health or mood disorder may increase your risk of PFS. In one small study of men who reported persistent symptoms after finasteride, 57% had a prior psychiatric diagnosis and 28% had a family history of mental health conditions. Because of this, some researchers suggest that mental health history may be worth discussing with your doctor before starting treatment.
Is post-finasteride syndrome real?
A very small percentage of men report post-finasteride syndrome symptoms after taking finasteride. While there’s no disputing that these cases do exist, the scientific evidence is limited and mixed as many studies on PFS don’t have large enough sample sizes, or are biased and therefore unreliable.
Ultimately, it’s not recognised by most medical experts and health organisations. For this to change, we need more high-quality research to fully understand the condition.
How common is post-finasteride syndrome?
PFS is considered very rare. Since 2012, the Post-Finasteride Syndrome Foundation has been contacted by over 3,000 patients reporting persistent symptoms. When you consider that millions of men worldwide have taken finasteride, this suggests lasting symptoms affect a very small percentage of users.
Post-finasteride syndrome treatment
There are currently no established treatments for post-finasteride syndrome. While some men say certain supplements or lifestyle changes helped them, results vary widely and aren't consistent over time.
Some men find their symptoms gradually improve or stabilise, usually within 6-18 months after they first appear. However, everyone's experience is different. In the meantime, healthcare professionals may offer therapeutic relief for specific symptoms. For example, they might prescribe medication for erectile dysfunction or offer support for anxiety or depression.
The best approach is to work with a medical professional rather than attempting self-researched treatments or sourcing hormones online, which carries significant risks. A healthcare provider can help rule out other potential causes, manage your symptoms and support you safely.
How long does post-finasteride syndrome last?
Experts still aren't sure how long post-finasteride syndrome lasts, and studies haven't confirmed whether symptoms eventually resolve or can be permanent. Some men report improvement over time, while others report symptoms persisting for years.
One small observational study found men still reported symptoms around 44 months after stopping finasteride. Another review found that symptoms remained in most participants 14 months after follow-up. Ultimately, research is mixed and no study has clearly defined how long PFS symptoms might last.
Because PFS is rare, medically contested and not fully understood, it’s important to speak with a medical expert about any continuing symptoms.
What to do if you’re concerned about finasteride side effects?
If the thought of PFS has made you hesitant to try finasteride for hair loss, there are ways to reduce the potential risks while still promoting hair growth.
You could use the lowest effective dose of finasteride and stick to regular check-ins with your doctor to monitor how you’re doing. Some men explore topical finasteride, which is applied to the scalp rather than taken orally. Others combine finasteride with minoxidil, which works through a different mechanism and can improve results while allowing for a lower finasteride dose.
Work with a healthcare professional rather than experimenting on your own, or speak to MANUAL’s experts for a personalised treatment plan. This includes regular monitoring of symptoms to help you weigh the benefits and risks, suggest the safest approach for your situation, and adjust your plan if side effects appear.
Sourcing medications online or trying unproven treatments might seem quicker and easier, but it can be unsafe and unpredictable.
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