This is what’s written about PFS.
Finasteride, dutasteride and saw palmetto are 5 alpha-reductase inhibitors that can trigger an enduring sexual dysfunction with a very similar profile to PSSD . As the name suggests, PFS is most commonly associated with finasteride which was licensed for the treatment of male pattern baldness in 1997. In 2011, a warning for erectile dysfunction that persisted after stopping treatment was added to the US product label for the finasteride products, Propecia and Proscar. This was updated in 2012 to include libido disorders, ejaculation disorders and orgasm disorders that continued after discontinuation of Propecia, and decreased libido that continued after discontinuation of Proscar . There should be no prior use of isotretinoin or an SRI when making a PFS diagnosis. Sexual dysfunction that happens on finasteride but clears after treatment stops is not PFS.
(1) Prior treatment with a 5 alpha-reductase inhibitor.
(2) Enduring sexual dysfunction after stopping treatment.
(3) Enduring reduction or loss of sexual desire.
(4) Enduring erectile dysfunction.
(5) Enduring reduction in genital and orgasmic sensation.
(6) The problem is present for ≥3 months after stopping treatment.
There should be
(7) No evidence of pre-drug sexual dysfunction that matches the current profile.
(8) No current medical conditions that could account for the symptoms.
(9) No current medication or substance misuse that could account for the symptoms.
(10) No other prior medication that could account for the symptoms.
A number of related features may stem from finasteride without being diagnostic for PFS:
- altered seminal quantity and quality.
Additional finasteride effects that can occur independently of any sexual difficulties but may also accompany sexual problems include:
- cognitive impairment
There is some evidence for penile curvature or other penile effects in men with PFS , but it is not clear if this was present prior to treatment or has resulted since. Alterations in neuroactive steroid levels , methylation of 5 alpha-reductase type 2 in cerebrospinal fluid , and gut microbiota population  have also been found in PFS patients. But again, it is not clear whether these were present before treatment.