A patchy beard isn't a grooming problem — it's a follicular one. No oil, supplement or minoxidil routine will create density where follicles don't exist. Beard transplant is the only permanent solution, and modern FUE techniques make it virtually indistinguishable from natural growth.
Hair follicles are extracted from the back of the scalp (the same donor zone used for hair transplant) and implanted into beard, moustache, sideburn or goatee areas. Once established, the transplanted hair grows like beard hair — you can shave, trim, style and grow it normally.