Home Remedies For Hair Growth: Onion juice:

This is the oldest and the most efficient hair growth treatment. Onion juice is rich in sulphur, which boosts the production of the collagen tissues and thus helps in the re-growth of hair.

You can use red onions or shallots by chopping it into small pieces and then squeezing out its juice. Then apply it on your scalp and keep for 15 minutes. Finally rinse off with a mild shampoo. Here is an excellent post on how onion helps hair growth.