If I stop Propecia for 4-5 months and lose some hair, will I regain them back if I restart the medication?

Thank you for your question. I would not recommend stopping your finasteride (Propecia) therapy unless you are having side effects from the medication. It is very likely that some of the follicles you shed after discontinuing the finasteride would not grow back. You could consider substituting a topical product such as Revivogen MD which blocks the effects of DHT at the scalp level.I hope this was helpful - Dr. Moore

Everyone is different, but I wouldn't count on it. It's possible you would gain back everything you lost during that period, but it's also possible that you wouldn't gain any of it back. What's most likely is that you'd regrow some, but not all, of the hair you lost. Don't take a break from it unless there's a good reason to.

Most people who start and restart finasteride never regain the density they once had. Shedding will occur when the finasteride is stopped and then once the finasteride is restarted shedding will slow. Most people never get back to the same density.