Im 25 years old , dose biotin helps me getting full thick beard ?

No, and ...: Biotin deficiency is rare, but can occur in persons with genetic mutations, on long-term antibiotics or anti-convulsants, or who eat a lot of raw egg whites. There is no good evidence that this over-the-counter supplement is the magic potion to thicken hair, grow hair, or prevent hair loss. Biotin is safe to take in the usual amounts, but not in the huge doses that some websites are suggesting.