Does Shaving Make Hair Grow Back Thicker?

The belief that shaving causes hair to grow back thicker ranks right up there with the misconception that pizza causes acne. It’s a myth that Joshua Zeichner, M.D., board-certified dermatologist and associate professor of dermatology and director of cosmetic and clinical research at Mount Sinai Hospital, emphatically debunks. “When the hair is removed at the root — for example, after waxing or tweezing — a new hair grows in its place. This new hair starts off narrow, but eventually thickens as it grows back,” he says. “When you shave, you are transecting the hair at its thickest part, so it just appears to grow in thicker. However, in reality, it is no thicker than it was before; you’re just seeing it at its widest diameter.”

As far as hair density and growth rate are concerned? These things are determined by genetics, the dermatologist says. But if you want to do something about what you’ve got, there are options. Laser hair removal, which uses targeted wavelengths of light to destroy the root of the hair, “is a great option for people who have light skin and dark hair,” Dr. Zeichner says. “The laser is not as effective for light or white hair, and people with darker skin tones are not good candidates because pigment in the skin itself can distract the laser from reaching the follicle.” (Note: there have been some recent developments here, but you have to find experts who work with darker-skinned patients.)

Another option: Prescription medication, such as spironolactone, is available to block the effects of hormones on the skin. (Your hair’s cycle and follicle structure are highly affected by many different hormones.) While the drug helps enhance hair growth on the scalp, it can help reduce hair density on the face and below the neck, Dr. Zeichner says. Additionally, eflornithine, a topical cream the FDA approved to treat excessive hair growth, has been shown to block an essential enzyme needed for the production of hair, resulting in slower and less dense hair growth overall.