Does Cutting Hair Really Speed Up Growth? Dermatologists Weigh In

The notion that trimming hair results in quicker growth or greater thickness is a long-standing myth, as confirmed by dermatology specialists. The actual rate of hair growth is determined by the activity in the hair follicles beneath the scalp, not by the hair that is cut from the ends.

How Does Hair Grow?

Desmond Tobin, a professor of Dermatological Sciences at University College Dublin, explains that hair grows from follicles located 2 to 4 millimeters below the skin's surface, where hair fibers are formed before they emerge on the scalp. Once hair is visible and can be cut, it is essentially dead tissue; thus, cutting it does not influence the biological processes that govern its growth.
The average hair growth rate is about one centimeter per month during the active growth phase, which can last for years before the hair sheds and regrows. Tobin adds that this growth rate is genetically determined and cannot be accelerated by frequent cutting.

The Role of Regular Trims

While cutting hair does not speed up growth, it can enhance its external appearance. Heat styling, hair dyes, and chemical treatments can weaken the hair shaft, making it more susceptible to breakage. When hair breaks off faster than it grows, it may appear as though it is not growing at all.
This is where regular trims come into play: cutting split ends reduces breakage and gives hair a healthier, fuller look. Tobin likens this to "trimming a hedge"; it does not change what happens beneath the surface, but it creates an impression of fullness and neatness.

Tips for Maintaining Hair Length and Health

Experts recommend that individuals looking to grow their hair focus on minimizing damage by reducing exposure to heat and chemical products, and by keeping hair in its natural state as much as possible. Proper hair care helps maintain length and gives hair a healthier appearance over time, without relying on cuts to hasten growth.