I've tried oral finasteride, topical minox, oral minox, oral dutasteride, etc and usually at least 2 of those things in combination. I searched for a long time and found a solution that is strictly topical, but delivers dutasteride (superior to finasteride) locally to the scalp with much less systemic absorption so your concern of oral fin or better, dutasteride side effects are severely diminished. The solution also contains minox, naltrexone, among others including latanoprost (you may have heard of it as latisse, a very expensive eyelash growth solution.). There are more things in it, but it has held onto my hair through many DHT derivative cycles.
It's called Powers Hair Solution 5.1, I can post a picture if you'd like, but it's from a company called agelessRX.
I started losing my hair at 21 pretty aggressively, even though as a child and teen, every barber I went to would comment how thick my hair was. Within a few months it visibly improved it greatly and about 9-10 months after, I already had the insanely thick hair I used to have growing up.
This isn't an advertisement, just a possible solution. The only way these guys are affiliated with me is by taking my money