Hair growth

So recently I started to use castor oil for my lashes and idk if it's just me but I think is been working but then again I've only used it for about 5-7 days but anyways i wanted to use a castor oil and coconut mixture for my hair since castor oil thickens and darkens (my hair from the front is thinner than the rest of my hair since I tied my hair super tight for about 1 year and a 1/2) so I wanted to know if it would work to make my hair thicker again so if anyone has tried castor or coconut oil pls lmk if it worked for you