While the thickness of a man's mustache is based in large part on genetics, it is possible to grow a thicker mustache by making the right dietary choices. Even those whose ethnicities are not known for facial hair stand a good chance of cultivating thicker mustaches if they consume the right balance of nutrition. Even a man's hormone levels are subject to change with the right diet.
A man should avoid eating processed foods, which do not provide enough quality nutrition to help grow thick, lustrous hair. These foods include most fast food along with anything containing preservatives. Instead eat fresh, whole foods, high in protein and healthy fats, both of which contribute to a thicker, more vibrant mustache. Nuts, lean cuts of meat and fish qualify.
He should be sure to consume enough vitamins and minerals. This is easier to do if he relies on a quality supplement. B-complex vitamins in particular aid in hair growth. This is especially true of biotin, B-12, B-6 and B-3. Meanwhile, vitamin E stimulates blood circulation to follicles and vitamin C aids in general hair growth.
In addition to diet, tips for growing a thicker mustache include regular grooming, which stimulates hair follicles, and applying a coconut-based oil, which makes hair appear fuller.