A 1928 study found that there is no evidence that shaving accelerates the rate of hair growth. This directly compared the rate of hair regrowth among shavers and those that let their hair grow naturally.
In the study, four men shaved a portion of their facial hair using the same brand of shaving soap, new razors and a consistent water temperature. The scientists conducting the experiment collected the hairs after the men shaved and compared 100 of the hairs each time the regrowth was measured to reach their conclusion. According to the Mayo Clinic, shaving the hair gives it a blunt tip. This gives the illusion that the hair is darker or thicker, which often makes it appear to be growing faster than it actually is.