Wait, did he not officially prescribe you finasteride? That means he probably knows what is up with you, he cannot legally prescribe it but tells you “look finasteride topical spray is good if you can get it” Because for topical finasteride you need prescription too.
NO. 1)Minoxidil is not approved for <18 individuals. 2)Minoxidil does NOT prevent the progression of AGA but it regrows what you had lost. Here is what you have to do:
1- Go see a proper endocrinologist to have your development (endocrinological maturation) assessed. Check your body, facial and genital hair too and assess your tanner stage yourself and tell your relevant tanner stage to endocrinologist. This can be useful if you want to hop on oral finasteride.
1.5-See a dermatologist again on discussing topical finasteride.
2-For minoxidil, topical minoxidil is technically not approved for age<18 people. So you cannot legally use it but it probably works. This is a gray zone. It will work if you are a responder to topical minoxidil but please keep in mind that I won’t recommend it due to legal reasons.
3- Without finasteride/dutasteride, if you have androgenetic alopecia, you are cooked. Period.
4-If in your budget, please also see a cardiologist to assess any danger that topical minoxidil may possess for someone at your age although that risk is probably low and that “minimum 18” requirement likely is one of legal than of medical. Though still if possible see a cardiologist.
5-Hurry up, diffuse thinning is no fucking joke. Get EVERYTHING sorted if possible in at most a time period of 1 month. What path to take, what medicines to use or not to use etc.
Read these studies and then you would understand why DHT is absolute of a hell to scalp hair in all regions except the horseshoe area (where little thinning occurs at most, but other regions are “cooked”)
Below is a one on perifollicular fibrosis, this one is especially nasty. T induced, but prob. DHT plays the main role here and T is used colloquially as DHT is derived from T.
https://www.jstage.jst.go.jp/article/bpb/29/6/29_6_1246/_pdf
ps: Legal disclaimer; I do NOT advise, endorse or condone the use of any medicines without a doctor’s advice. Use at your own risk.