What is the 'sweet spot' Finasteride dosage for DHT reduction? (photos)

Hello doctors and patients. I am 45 yrs old and thinning (MPB) since age 20. I am NW 6 but holding steady thanks to Rogaine, Nizoral, Argon shampoo, and Biotin. I recently started Finasteride to help thicken/regrow hair, and I need advice regarding dosage. Currently, I split 5mg into 4 pills (1.25mg) and take one every M, W, F. Could I expect a similar benefit (in terms of DHT inhibition) with a smaller dose of say .62mg, taken daily or every M, W, F? Finasteride Inhibition Curve