People might call it a bit misogynist but I generally don't trust most female dermatologists cause they don't have to deal with hair loss themselves (and if they do, it's an unfortunate much more rare form that isn't male pattern baldness, but an immune system issue).
However your hair looks great, especially at your age, and if you were to take ANY "preventative measure" check out the microdose thread this guy made:
https://www.gourmetstylewellness.com/intera...teride-test-commence-contains-pictures.99873/ the OP quit but other people have had success on it.
You could do something like 0.03mg 2-3 times a week and probably maintain what you have indefinitely. But you definitely don't seem like you ever need to take the 1mg daily dose, which is way too much for the majority of people already.
Nizoral and biotin help thicken the individual hairs you already have. can do something like take two 5,000 mcgs a day, or if you have the 10,000 mcg biotin tablets, cut them in half and take twice a day spaced apart so you get better absorption. Nizoral won't give you any side effects as it's supposed to be anti inflammatory, anti fungal, and mildly anti androgenic.
Edit: I just read that you decided to take 1mg daily, but I suggest you lower to 0.2-0.25mg daily because you have very mild loss if you have any at all. finasteride has a cumulative effect.