How can i thicken my fine hair?

use a better shampoo, with conditioner.

Lydia you ask how you can thicken your fine hair. I am assuming you are not talking about your hair thinning and are seeking to strengthen the hair follicles.

Biotin is a natural nutritional supplement that assists to restore hair loss and it also is like to keep skin and nails looking healthy. Recommended by doctor’s, Biotin contains B-vitamin, which is found in rich foods like soy, egg yolks, liver, kidneys, milk, cheese, butter, poultry, cauliflower, bananas, watermelon, peas, brewer’s yeast, nuts, beans, oat bran, salmon, and mackerel.

Your can read more about vitamins for healthy hair here.

Use a conditioner that contains proteins which will help thicken up hair .

am sure you wud b using some good shampoo and conditioner but still if you are not satisfied with the results then try changing the same. Try diff shampoo and conditioner and yes vitamins is necessary for healthy hair. Try Fsc Head High Hair Vitamins & Minerals

I would recommend clip in extensions to add volume and length my hair is thin and I clip them in and they look gorgeous and make my hair look full :) i baught mine from www.buyhair.co.uk from the Balmain section! they have lots of different sets though! check them out 
hope this helps Michaela x

Use aloe vera or herbal shampoo.