While most women in the United States do whatever they can to get rid of their underarm hair, many men -- and some women -- actually want more of it. Underarm hair, which first appears in boys and girls at puberty, may stop growing as a result of cancer, pregnancy or other hormonal conditions. A lack of underarm hair may also be a symptom of malnutrition.
If you are waiting to get underarm hair as a result of puberty, remember that everyone goes through puberty at different speeds. You may be showing other signs of puberty that your friends are not, and vice versa. Not having underarm hair doesn't mean anything about your masculinity; hair growth will happen eventually. Discuss your concern with your doctor if you feel you are not developing as quickly as your friends; but chances are, your development is normal and you'll catch up in due time.
Malnutrition and vitamin or protein deficiencies may cause slowing of hair growth or hair loss. To ensure your body has the nutrients it needs to maintain healthy skin and hair, eat a balanced diet. Get essential vitamins and minerals from fresh fruits and vegetables, and eat lean protein and unsaturated fats from sources such as turkey, nuts, avocado and vegetable oils. A daily multivitamin may also help supplement any vitamins you may be missing in your diet. See a doctor if you suspect you have any nutritional deficiencies.
"Marie Claire" magazine recommends massaging the scalp to help stimulate hair growth; the same process may be used on the underarms. Raise one arm above your head and use two fingers from your other hand to massage the underarm in small circles. If you wish, you may perform the massage with a few drops of eucalyptus oil; this oil may stimulate hair growth and make hair more manageable, according to K. Nakamura and colleagues in a 2005 report entitled "Effects of Eucalyptus Extract on the Properties of Human Scalp and Hair."