I haven’t tried these remedies personally, but from what I’ve read and heard, most of them don’t really work to reverse hair loss, at least not in a significant way. Rosemary oil might help a bit with blood circulation to the scalp, and some people say it can slow down shedding if used regularly .
Onion juice, on the other hand, is supposed to help because of its sulfur content, but the smell alone is enough to turn most people off. Aloe vera is more about soothing the scalp and reducing irritation rather than regrowing hair.
That said, these are more like supplements to a proper treatment plan rather than standalone solutions. If you’re dealing with genetic hair loss, things like minoxidil or finasteride tend to be way more effective.