Recently, our Shanghai Mama community groups have played host to some interesting discussions and questions regarding laser hair removal, not only for themselves, but also for teens. We reached out to the experts at Jiahui to understand a bit more about the process and the different kinds of lasers. Check out the resulting collection of laser hair removal dos and don’ts below.

What is laser hair removal?
Laser hair removal is one of the most commonly used methods of hair removal. This method works based on the principle of selective photothermolysis, whereby the laser beam is set at a specific wavelength and penetrates the surface of the skin to reach the hair follicle. The hair follicle absorbs the light energy, converting it into heat energy which destroys the hair follicle, thereby resulting in hair removal.
There are many types of lasers on the market. The Gentle Laser Pro (755nm), which is used at Jiahui, effectively removes unwanted hair on all skin types, and is best suited to fine and light-colored hair removal. It has a dynamic cold spray technology, which releases a -20°C cold spray to instantly cool and effectively protect the skin – this is essential for darker skin tones. The laser beam can be adjusted from 3-24mm, ensuring a higher degree of safety and no need for gel, ensuring optimal comfort.
Relationship between laser energy level, skin tone, and hair diameter
The efficacy of laser hair removal is related to the number of treatments as well as the energy level used during the treatment. The energy level used will depend on skin color and hair diameter. If an incorrect energy level is selected, it can cause pigmentation and blistering.
Typically, hair diameter is inversely proportional to the energy level required. For example, the larger the hair diameter, the more target molecules are present, meaning that the level of energy absorption is also higher.
For areas such as the hairline, beard, etc., it is necessary to use a low energy level, because the hair follicles are closer together, meaning that the absorption and diffusion of the light energy are enhanced.

When doing laser hair removal, it is essential that the correct laser energy levels be selected according to the specific areas of the body, skin tones and hair diameters in question. This will ensure the best results and reduce the occurrence of unwanted side effects.
Is there an age limit for laser hair removal?
Typically, laser hair removal is not limited by age. It is possible for minors to undergo laser hair removal to remove excessive body hair. However, as children have lower levels of immunity, laser hair removal can sometimes have a negative impact on their skin health, leading to folliculitis, melanosis or enlarged pores.
What is the difference between a home hair removal device & clinical laser hair removal?
Home hair removal devices predominantly irradiate the laser beam to the root of the hair follicle, thereby inhibiting hair growth. In this instance, the hair removal is only temporary.
Typically, home laser hair removal devices are cheaper and emit lower energy levels.
Therefore, in deciding between the two methods, it is necessary to choose according to your specific circumstance and needs.
Other hair removal options
- Shaving: Shaving hair with a razor is the most traditional and commonly used method.
- Tweezing: Pulling hair out with tweezers can be used to remove excess hair.
- Bleaching: Although hair bleaching is not a method of hair removal, it can make the hair lighter and softer, and resulting in ‘false’ hair removal.
- Electrolysis: Electrolysis uses a low-voltage direct current to cause electrochemical damage to hair follicles.
Most of the above methods only remove the epidermal hair shaft and do not destroy the deep hair follicles to prevent hair regeneration.
Although electrolysis can destroy hair follicles, it takes a long time, is more painful, requires high precision, and is cumbersome. This process destroys hair follicles one by one, which cannot achieve the purpose of complete hair removal. Additionally, this form of treatment may cause scarring.
Laser hair removal dos & don’ts
- Do not use depilatory cream or other cosmetics on the hair removal area before treatment.
- Use sunscreen on the area for one month after treatment to avoid pigmentation.
- Apply moisturizing body lotion to reduce the chance of pigmentation.
- Wear loose cotton clothing to prevent inflammation.
If you have any questions or would like to make an appointment with the Department of Dermatology, please scan the QR code below.
