I had a legit prescription for 3 months Finasteride but I need to book in for a follow up to get more as I have run out of tablets since last week. I recommend Finasteride, it gets a thumbs up from me so far.
If I wanted to go for Dutasteride I would most likely have to source elsewhere as I doubt I would have an easy time getting hold of a prescription for it. Also, the safety profile is a little more controversial than finasteride. I've read varying stories of it working wonders and also causing disasters...
Interestingly, the 5% minoxidil/Azelaic acid (also has retinol in it) seems to be sprouting longer vellus hairs just below my hairline on my frontalis muscle so I will take this as a good sign.
Im a 17 year old on dutasteride but I dont see why you would try it. Your hair look good and from the looks of it finasteride is working for you. Dont try it unless you run out of all other options.