Use methi Dana and kalonji.. soak this overnight and next morning on an empty stomach have this water and even chew the seeds .. this did help me in reversing grey hair n hairfall too and using topical application of serums also works great. I used ThriveCo's HairGrowth serum which helped in new hair growth in just two weeks ... my new hair growth was thicker and stronger and in 6 months I got full volume.

Yes, it's possible but we need to keep ourself peacefully no stress, proper diet and fitness. And mainly need to use good products for our skin & hair. I would suggest ThriveCo products to ur cousin. Hair growth serum is there is really amazing it's helps to recover the damaged hair and grow the baby hair with good textures.