Cutting your hair does not make it grow faster or thicker.

Hair growth is a biological process that takes place in the hair bulb located within the follicle. This process is divided into three distinct phases: anagen (growth), catagen (transition), and telogen (resting). Because the hair visible above the skin consists of non-living keratinized cells, cutting it has no physiological impact on the follicle's activity. Research published by the American Academy of Dermatology confirms that the average human hair grows about 0.5 inches per month, or 6 inches per year.The perception that hair grows back thicker after a trim is a common optical illusion. When hair is cut, the tapered, thinner ends are removed, leaving behind the thicker base of the hair shaft. This makes the hair appear more dense and uniform, even though the actual diameter of the individual strands remains unchanged. Factors such as age, diet, and scalp health are the true drivers of hair quality and speed.A landmark study published in the Journal of Investigative Dermatology as far back as 1923 debunked the myth that shaving or cutting hair stimulates growth. Scientists found no evidence that external grooming affects the internal mitotic rate of the hair matrix. To improve hair growth, medical professionals recommend focusing on internal factors like biotin, iron levels, and protein intake rather than external trimming schedules. Regular trims are still beneficial, however, because they prevent split ends from traveling up the shaft and causing breakage.