How Does Hair Grow Back Once You Cut It?

Hair grows approximately one fourth of an inch per month.

Hair is composed of keratin cells similar to the cells that make up your skin and nails. Your hair has three cycles of growth. These three cycles are the anagen, catagen and telogen phases. Each hair enters the different phases of growth on its own. When you cut your hair, it grows back from its roots located in your scalp.

Construction of the Hair Root

Your hair shaft grows out of its root which is located in the follicles in your scalp. Each follicle contains a structure called the dermal papilla which provide your hair root with nourishment from your blood stream. Sebaceous glands, also known as oil glands, are located beside your hair root and provide lubrication to the hair.

Construction of the Hair Shaft

Each hair has three components. The inner layer or medulla may not be present in fine hair. The second layer, the cortex, gives hair strength and contains the molecules responsible for hair color. The cortex also gives hair its texture. The outer layer, the cuticle, is made up of small scales and is the part of hair shaft that we see.

Anagen Phase

The first phase is the anagen phase, the active phase of hair growth. The hair follicle and dermal papilla are joined and cause the hair shaft to grow. A hair may remain in the anagen phase for up to six years. Approximately 85 percent of your hair is in the anagen stage at one time.

Catagen Phase

The catagen phase is also know as the transitional phase. In this phase of hair growth, the hair follicle starts to shrink and eventually the hair shaft breaks away from the dermal papilla. The dermal papilla now begins a resting state in this phase. The catagen phase can last from one to two weeks.

Telogen Phase

The final phase of hair growth is the telogen or resting phase. Your hair stops growing but it is still attached to the hair follicle. This phase of growth can last for five to six weeks. At the end of the telogen phase, the hair growth cycle begins again and the hair enters the anagen phase. The old hair is pushed out of the hair follicle by the new hair if it has not already fallen out.

References

• Follicle.com
• Milady's Standard Cosmetology, 2004