It's caused by DHT forming around hair follicles. The best thing for it is a Polysorbate 80 shampoo. Polysorbate 80 removes the DHT.
I'm 54. I've spent years on at 2-3 grams of test a week. I've been juicing for about 30 years. I have a full head of hair and all the males in my family are bald. I've used Pearson and Shaw's Inner Shampoo since my mid 20s.