Hubby's hair is thinning

I need help my hubby's hair is starting to thin out at the top in the middle and on his sides. He's been growing his hair out and I've been braiding it. I want to know what exactly could I use to get his hair to grow and to thicken his hair where its thinning?

Thanks

You can try Jamaican Black Castor Oil. That's supposed to help thicken up hair and help it grow. It's also a great sealant.