These are the ingredients that are intended to nourish and beautify, making your hair shinier, smoother, softer, thicker, and more manageable.

If Sam didn't also take a daily multivitamin and a calcium-magnesium supplement to make up for lost nutrients, Vogelstein writes, his growth would be stunted and his teeth and hair would fall out.

Some claim that nutrients like copper peptides, biotin, folic acid, and others may help support healthy hair.