My understanding as a Minoxidil user is that it's mostly a preventative measure to prevent further hair loss. It certainly can regrow some hair, there's plenty

My understanding as a Minoxidil user is that it's mostly a preventative measure to prevent further hair loss. It certainly can regrow some hair, there's plenty of evidence of that, but it's definitely a limited amount. It certainly won't give a bald man a full head of hair. You can't just compare the before hair count to after, because presumably if you didn't use it you would have lost even more hair in that time. Unfortunately you can't know how much that would have been - but just say you would otherwise have been down to 140 h/cm^2 in that time, then the effect is 28 h/cm^2 instead of 18. Even if the amount of hair stayed the same, if it prevented more balding it would be helping. Whether it's worth it or not is up to you.