finasteride can absolutely leave your hair in a worse state. I speak from experience. finasteride fried my hair everywhere, areas that I had no problems and even areas that are 'safe' like the donor area and sides. Familiarize yourself with AR upregulation. Look it up. Nobody talks about this but in some cases, probably rare, finasteride can backfire due to AR upregulation, where by the hair follicle makes more receptors/becomes way more sensitive to DHT. Scalp hair follicles have a high affinity for DHT and this is why suppressing it with finasteride is so effective for most at slowing, sometimes reversing hair loss.
When I tried to get off a drug that only greatly accelerated my hairloss/miniaturization. I tapered down from .5 mg, a dose that I was stable on for 6 months, to .25 mg and within one week I lost probably 60% of my hair overnight and my hair rapidly miniaturized in the following days. Had this insane rate of hairloss not happened to me I would have not believed it. I've posted the pics a couple of times already. Check them out. It's unreal. Also the hair in my nape and donor area just melted off. Basically, finasteride made all of my hair extremely sensitive to DHT so I am stuck taking it still or I would effectively be bald in weeks.
When something like this happens it is not likely to return to normal sensitivity again even if you quit the drug. So, if you start and have to stop for whatever reason, there is a good chance that it will accelerate your hairloss compared to if you had never taken finasteride.
You have no way of predicting this kind of reaction. I believe it happens to men who are already losing hair despite already low DHT levels. Given that we know receptors can compensate in response to a low amount of a hormone, it's not hard to see how this could backfire on someone losing hair with already very sensitive to DHT hair follicles.
Given my experience with finasteride (I am far from alone in this kind of reaction) I would strongly recommend starting at a lower dose, like .25 mg - .375 mg (3/8 of a 1 mg pill) and to not go above .5 mg as the flat dose response curve shows that there is almost zero benefit to going above that. My experience confirms this as I started on 1.25 mg for 16 months and then tapered down to .5 mg for 6 months with no problems. I think my hair got a little better even. People throw around that .25 mg is just as effective as 1 mg, but again, my experience, along with the experiences of others, disproves this. I believe that for some, less is more, ie, someone who is doing well on .25 mg, could do worse on 1 mg.
The varied reactions to finasteride are all over the place. Some guys can take it for 10+ years, quit, and experience no 'catch up' hairloss, and then you have me that went from .5 mg to .25 mg and after one week lost 60% of my hair overnight.
Before you start finasteride (I just re read the OP and it sounds like you are already on it), look at many shed hairs. They should be of even thickness from tip to root. Mine were until I started finasteride. They started rapidly thinning towards the root. I noticed this a couple of months into treatment and should have heeded that warning, so watch out for that.
One last thing, there is a pathological denial on hairloss forums that finasteride can accelerate hairloss in some guys, especially on the subbreddit Tressless. It absolutely can. Check out pjhair and buckthorn's experiences. Don't bother reading Rassman's forum posts either, he is less than useless.
