Up to 20% of subjects reporting persistent sexual dysfunction for 6 or more years after stopping the drug, suggesting…that it may never go away.

[Propecia] has the sexual side effects, like erectile dysfunction, which can affect men for years. It’s something the drug companies had to disclose over the last decade: “Difficulty achieving an erection that continues after stopping the medication,” side effects that may even be permanent. Up to 20 percent of subjects reporting persistent sexual dysfunction for six or more years after stopping the drug, suggesting the possibility that it may never go away.

—Pills for Hair Growth: YouTube, June 2022