Allez au contenu Allez à la navigation

Sun for everyone

Tchats extracts


To learn more about sun protection for everyone, explore responses from dermatologists and allergists to questions submitted by internet users during chat sessions organised by Bioderma.

An internet user’s question

Does sun cream dry out the skin?

It’s not sun cream that dries out the skin but rather sun exposure. It is best to use moisturising creams after exposure.

People with the skin of a redhead cannot tan. Indeed, skin pigmentation is due to melanocytes. These cells produce melanin, a coloured pigment. There are two types of melanin: pheomelanin (red or orange melanin, potentially photo-aggressive, which means that it produces free radicals) and eumelanin (brown or black melanin with photoprotective power). Red-haired people only produce pheomelanins, which is why they cannot tan and must protect themselves by using a SPF 50+ sun cream.

You have indeed used up a large part of your sun capital and the unfortunately the damage has already been done. This is a natural “actinic” (due to the sun) ageing process. Conclusion: avoid the sun and protect yourself more and more.

In theory, a protection factor less than or equal to 20 means that the sun product is capable of protecting you from the sun. In practice, the actual protection factors of these products are much lower because they are never applied liberally enough and so their protective power is very low. That is why it is best to choose higher protection factors (for normal skin, SPF 30 is a good compromise).

I think that in your case, you should use sun creams at the beginning of your holidays: it will keep you from getting a sunburn without keeping you from tanning. Once you have a tan, external photoprotection is less important, but remember that tanning easily does not provide protection against the long-term effects of the sun (ageing and skin cancer).

There is no such thing as a genuinely waterproof sun cream; it must be reapplied frequently, in particular for children. All the more so as ultraviolet rays are reflected by the water in a swimming pool.

SPF means Sun Protection Factor: it shows the ability of a sun product to protect from sunburn. The UVA protection index simply shows the ability of a sun product to more or less stop ultraviolet A rays. There is no real relationship between the two. Why is it important to know the UVA index? Quite simply because UVA rays are responsible for a non-negligible percentage of exposure’s long-term effects (malignant melanoma, ageing, etc.). A good external photoprotector should have a high SPF (30 or more) and also a high UVA protection index (at least one-third of the SPF).

It all depends on several factors: 
1) Your phototype; 
2) Your activity (what you are doing); and
3) Your age. 
In practice for a subject with a "normal" phototype or normal skin (someone who regularly gets sunburns but easily tans), a protection factor of 30 is sufficient, as long as the product is re-applied frequently. A very fair phototype (constant sunburns and no tanning) must use a protection factor greater than or equal to 50 and avoid exposure in the middle of the day. Children should first have photoprotection from clothing; photoprotectors are supplementary. Choose mineral screens with a protection factor greater than or equal to 30. Extreme conditions of exposure (mountains, glaciers, tropics, etc.) require the highest possible protective factor and frequent re-application.

Exposed areas must be protected (décolleté, arms and legs). In addition, sun exposure is more intense in the mountains, so you need to protect yourself with an SPF 50+ sun cream and wear suitable clothing.