I can give you anecdotal evidence.
My hubby had his T levels tested and while I never got to know his actual levels, the doctor said they were normal and offered nothing else to help. Hubby had been waking up without an erection for about 3 months and there was no sex or sex drive.
So after I Gooogled "how to increase testosterone levels naturally" and MDA came up I immediately started him on 5000iu of Vit D and zinc, cleaned up his diet from sorta Primal to actually Primal. Within 2 weeks he was back to normal. And in the past 12 days we've had more sex than we've had in the past 6 months.
Good luck, I hope you can get your T levels up without weekly injections.