Even without microneedling, imo topical dutasteride probably goes systematic but maybe its limited. I only have anecdotes. From the bloodwork from people if it is accurate it went systematic. Few got sides, few did not.
It seemed just like topical finasteride to me but with topical finasteride, we have at least 1...
I think it comes down to individual reaction on finasteride. There are apparently guys that nuke 70% of DHT on finasteride and some nuke more on dutasteride and are fine, others take even a little bit and get lots of sides sometimes even persistent side effects.
https://onlinelibrary.wiley.com/doi/10.1111/jdv.17738
Only study I could find, that too topical finasteride. 35 % inhibition with 0.5mg maximum finasteride everyday.
I see. I believe Saw Palmetto nukes 30 % of DHT at least that is what I read in studies. So, I am assuming lower finasteride dosage to mimic that would lead to the same but we probably do not know how much finasteride is needed to nuke that much.