My brother is 26 years old n his head is almost bald what should he do to grow his hair thick and well?

See a dermatologist: There are only two drugs that are fda approved for hair growth: rogain and propecia (finasteride). Neither one is perfect and both may have rare side effects. They also don't work in individuals who have lost their hair for a long period of time. Your brother should consult a dermatologist to see if these drugs are appropriate for him.