Summer is coming, how to choose and use sunscreen?

Summer comes, for those who work outdoors, travel, swim… need to use sunscreen to protect their skin.

According to Dr. Vu Thu Trang – Allergy Dermatology Center (Military Hospital 108), sunscreen is an external product for the skin that absorbs or reflects some of the sun’s ultraviolet (UV) rays. radiation, thus helping to protect the skin from sunburn and most importantly, preventing skin cancer.

Not only women but also children, men or “sunwalkers” all need to use sunscreen to protect their skin. However, surely not everyone knows the full benefits of sunscreen.

Why should you use sunscreen?

According to Dr. Trang, there are 3 harmful rays in sunlight: UVA, UVB, and UVC.

Specifically, UVC: Rays that cause skin cancer, are blocked by the ozone layer, fortunately the ozone layer in Vietnam has not been punctured, so it still has the effect of blocking UVC rays from reaching the ground. Meanwhile, in places where the ozone layer is broken or thin, the risk of skin cancer from UVC is very high. Most sunscreens have no UVC protection.

UVB: Active at 9am – 2pm, strongest in the summer, affecting the epidermis, causing sunburn, tanning, skin irritation. UVB cannot penetrate glass but can be reflected through glass and water. Most sunscreens protect against UVB.

UVA: Active at 14:00-18:00, always present regardless of the season of the year, whether it’s sunny or not. It is even most active when it is shady, especially after rain. UVA penetrates glass and many fabrics.

This ray affects the dermis, affecting free radicals, collagen, elastin, and other components, causing aging, less elasticity, wrinkles, sagging, melasma under the skin. UVA also indirectly causes cancer and DNA mutations.

“Therefore, people who often go out in the sun need to use sunscreen to protect their skin. At the same time, they must wear hats, sunglasses, and clothes that cover their hands and face to avoid direct sunlight. into the skin”, recommended doctor Trang.

Which sunscreen should you choose?

Dr. Trang also said that there are currently two types of sunscreens on the market: physical sunscreens and chemical sunscreens.

A physical sunscreen (Sunblock) sits on the surface of the skin, acting as a physical blocker by deflecting and scattering UV rays away from the skin like tiny mirrors. The advantage is complete protection from UVA and UVB rays; effective immediately no need to wait; Will not clog pores.

However, this sunscreen has the disadvantage that it needs to be reapplied often; may leave a white mark on the skin; Liquid spray and powder formulations should be avoided as they are prone to drift.

Chemical sunscreen (Sunscreen) is absorbed into your skin and lies in the deeper layers. They absorb UV light and convert it to heat, which then releases the heat from the skin. When applying chemical sunscreen, you need to wait for about 15-20 minutes to be effective before going out.

With this type of sunscreen, it is more economical to use, each time you only need to apply a thin amount of cream, easy to spread on the skin and not reveal the cream.

It has the disadvantage of allowing exposure to some UVA rays; requires time to be effective, usually 15 to 20 minutes before sun exposure; May aggravate acne, rosacea and hyperpigmentation.

Dr. Trang recommends, if you are exposed to direct sunlight a lot during the day, then physical sunscreen is the best choice, especially if you have skin conditions such as acne, rosacea. or sensitive skin.

If you’re sweating or swimming and you’ll need to reapply your sunscreen regularly, consider a chemical sunscreen, and avoid the oxybenzone ingredient in chemical sunscreens if possible.

How to use sunscreen for the best effect?

To use sunscreen properly and effectively, according to Dr. Trang, it is necessary to do two things well:

Apply enough: Experts recommend using 2mg of sunscreen per 1cm2 of skin (that’s about 25-30g for the whole body and 1/4 to 1/3 teaspoon if used for the face) for the best sun protection effect. 1/4 to 1/3 teaspoon is equivalent to 1 amount of cream spread evenly from the base to the tip of the index finger.

Theoretically many high SPF sunscreen products can protect the skin for up to 8 hours, but under the influence of the environment, sweat, water or friction, they can be less effective. So you should reapply every 3-4 hours.

Apply correctly: Put the cream in the palm of your hand, spread it evenly, and pat it on your face, patting and applying the cream to the skin evenly. Do not rub in circles like when removing makeup or using a cream, because when doing so, part of the cream will dissolve into the skin’s natural oils and loosen, reducing the effectiveness of the sunscreen.

At the same time, this application helps the cream to absorb faster, dry and more evenly. If your skin does not absorb a large amount, you can divide the cream into 2 applications, pat evenly between 2 times is okay.