For a friend of course?
I did find this on line which suggests at one point they are still looking for a “real cure” for male baldness. The article as a point of contradiction, also comes with a long list of other cures in the sidebars just in case you can’t wait.
There is a great reference to10 Caffeine shampoo products for hair loss. No science or evidence!
I can’t wait to try the neem oil cure which ranks further up the page than caffeine. It is also easy to find. Just look in the garden shed, along with all the pesticides. It comes with a thorough ABC Gardening Australia recommendation. It’s totally organic and will help to control common problems such as aphids and whiteflies. At least if my hair does not grow back the leftovers will be useful in the garden.
Given hair is dead stuff, it seems more reasonable that any cure needs to act directly on the subcutaneous layer of the skin. Putting product on hair seems counterintuitive, and a waste?
I’ve also rarely noticed any males in Japan with baldness. As caffeine is a recent product in their culture perhaps they know something we are yet to discover about keeping your hair thick and dark into maturity?