What causes unwanted hair to grow? How does hair grow, and what is the recommended way of treating it?

There are many ways to treat unwanted hair, such as shaving it with a razor, Brazilian waxing, medical hair removal (epilation), and hair removal creams. Treating unwanted hair more effectively requires understanding the structure of hair and the mechanisms by which it grows.

Two key points in the structure of hair are hair papilla and hair matrix cells, located in the root of the hair.

Hair is made up of hair shafts visible outside the skin and hair roots buried in the skin. What should be noted in unwanted hair treatment is not the hair shaft that is visible to us. It is the "hair bulb" (or "hair ball") at the base of the hair root that is responsible for hair growth. Hair bulbs consist of two structures: hair papilla and hair matrix cells. Here we will take a closer look at the structure of hair papilla and hair matrix cells.

Hair papilla contribute to hair growth

The hair papilla are located in the center of the hair bulb, and inside it run thin blood vessels called capillaries. Capillaries are connected to blood vessels throughout the body and are responsible for delivering nutrients to the hair. In other words, they bring nutrients to hair to promote growth. Hair papilla are also responsible for managing the cycle in which hair grows. This is because the protein FGF-7 involved in hair growth is produced in hair papilla.

Hair matrix cells employ a mechanism to grow hair

Hair matrix cells are responsible for producing and growing hair. This is a mechanism in which hair grows by increasing the number of hair matrix cells. Hair matrix cells are located around the hair papilla and multiply by receiving nutrients from them.

The hair follicle bulge promotes hair growth

In actuality, hair does not grow simply through hair papilla and hair matrix cells alone. Hair is only produced when the hair follicle bulge issues orders for the hair to grow. The hair follicle bulge is an organ in the dermis that is closer to the epidermis than the hair root. Hair grows when the hair follicle stem cells and pigment stem cells there issue instructions to produce hair.

The mechanism by which hair grows is a four-step hair cycle.

Hair growth is related to a cycle called the "hair cycle." The hair cycle consists of four stages: the initial growth phase, the growth phase (anagen), the regression phase (catagen), and the resting phase (telogen).

1. Initial growth phase

In the early stages of growth, hair is still buried in the skin. Although it is not visible to the naked eye, the hair matrix cells have begun to activate within the skin.

2. Growth phase

During the growth phase, hair matrix cells become more activated. Nutrition is received from the hair papilla and cells actively proliferate. You will begin to see hair growing from the skin, and gradually the hair will become longer and thicker.

3. Regression phase

In the regression phase, the growth of hair matrix cells stops. In addition, the hair papilla that nourish the hair matrix cells becomes smaller, and a gap is created between the hair matrix cells and the hair papilla. In this state, the hair is more prone to falling out.

4. Resting phase

In the resting phase, the position of the hair matrix cells and the hair papilla is farther apart than in the regression phase. Hair in the resting phase becomes weak enough to fall out naturally, and it starts preparing for the next growth period.

Methods for treating unwanted hair based on these underlying mechanisms

Unwanted hair treatment methods include:

  • Shaving by razor
  • Epilation by laser or light
  • Hair removal creams
  • Hair inhibitor lotions
  • Brazilian waxing

Each leverages the mechanisms by which hair grows to treat unwanted hair. Let's now take a look at these different treatment methods while recalling the earlier discussion of hair growth mechanisms. We will also look at unwanted hair care using soy isoflavones, which have been attracting attention in recent years.

1. The growth rate of hair does not change when shaving with a razor

Shaving with a razor involves shaving the hair shaft. Therefore, the base of the hair shaft, which is the part where the hair grows, remains in the skin. Even if the hair shaft disappears, the hair matrix cells at the base of the hair root continue to grow, so there is no change in the speed at which hair grows.

2. Laser/photoepilation works only for hair during the growing phase

Laser hair removal or photoepilation is a hair removal method that uses a laser or light that acts directly on the structure of the hair. Laser hair removal damages the hair papilla to promote removal. By contrast, with photoepilation, heat from light is applied to the melanin pigment on the surface of the hair to damage it. Both are methods of treating unwanted hair that are more effective when performed during the hair growth period. However, the effect is diminished on hair that is in the regression and resting phases, and considerable time is required to perform the treatment on all hair.

3. Hair removal creams function by entering the pores

Depilatory creams may seem to have the same effect as shaving with a razor. However, these creams differ in that they enter the pores to actually dissolve hair. When treating unwanted hair with a depilation cream, the tips of the hair become rounded, giving it a nicer appearance.

[Click here for the pineapple soy milk depilation cream from Suzuki Herb Laboratory]

4. Curbing hair growth with hair inhibitor lotions

One method attracting attention in recent years using soy isoflavones to treat unwanted hair. Soy isoflavones contain phytoestrogens, which function similarly to female hormones. They activate female hormones, suppress the secretion of male hormones that contribute to hair growth, and make it difficult for unwanted hair to grow.

[Click here for the pineapple soy milk depilatory lotion from Suzuki Herb Laboratory]

5. Brazilian waxing removes hair at the root. It leaves skin looking clear, but can be damaging.

Brazilian waxing is a hair removal method that removes hair at the root in one pass by applying a thin layer of wax and peeling it off. It also removes old keratin and debris along with unwanted hair, so it gives a smooth finish. The effect lasts for about 2 to 3 weeks. The peeling process is painful, and the skin may become red and tingle, so it is important to take good care of the skin after treatment.


Preventing skin problems from self-treatment and encouraging beautiful skin--the right way The key to the way unwanted hair grows is the hair papilla and hair matrix cells in the hair root, but we must not forget the way the hair follicle bulge issues orders for those parts to grow hair. In order to get the most out of your treatment for unwanted hair, it's best to understand the mechanisms by which hair grows. While there are several ways to treat unwanted hair, we recommend depilatory creams, because they enter the pores and act directly, causing the tips of the hair to become round, giving it a clean finish. Another method worth trying is treating unwanted hair with soy isoflavones, which have been drawing attention in recent years for their benefits.