Hair loss product

Husband is dealing with baldness issue. He actually have no hair now because i always tell him to shave the remaining as they look funny where some parts got hairs and some don't. Ever since he shaved his head, it looked better and people complimented him on how he looked young with his head shaved. I just wish he uses some products that prevent hair loss back then. I know it will help even if the hair loss caused by hereditary. Now that his baldness issue is getting a lot worst, I don't know if there is any product that can bring back his hair though. If there is, i certainly convince him to try it.