It is normal to be almost 16 years old and still not have armpit hair, if there is a delay in the appearance of secondary sexual characteristics, you can carry out hormone tests and so on. The time of growing armpit hair varies from person to person, it can grow after the age of 16, and some people may have sparse armpit hair or no armpit hair at all, which is normal and no need to worry too much. The onset of secondary sexual characteristics occurs between the ages of 11 and 14 in males and between the ages of 10 and 13 in females. If no secondary sexual characteristics appear for a long time, you should go to the relevant department of the hospital for examination. If the hormone level is normal, you can wait patiently and pay attention to adequate sleep and nutrition. If the hormone level is too low, you should take hormone supplementation therapy under the guidance of your doctor.