Really reduced postpartum hair fall but small bottle

I had very bad post partum hairfall. Everytime I comb my hair, there will be a lot of strands of hair that will be left on my shirt and brush. I started using this shampoo from 13 November and now, there's visibly lesser hair loss. Not totally gone but significantly lesser. Love the smell too! The effect can be seen after 1 wash. My only gripe about this is the bottle is so small! Wondering how long it will last.