All medications have side effects. Hives, constipation, dry mouth, and headaches are common side effects in a lot of drugs. But in some cases certain side effect combinations can indicate an allergic reaction instead of being a side effect. Be sure to read the specific warnings on the drug to be sure.
Overall, the entire suite of B-complex vitamins is essential for good hair and skin. In addition to Vitamin B12, vitamins B3 and B6 are also critical for hair and skin growth and appearance. A balanced B-complex vitamin supplement provides the extra boost your hair and skin may need to look great.
Vitamins C, E and A are important for the health of the skin and hair. They increase the health and efficiency of the entire body, thereby freeing up the resources to feed your hair the nutrients it needs on a daily basis. They help promote healthy connective tissues and cellular growth.