This is the reflex of summer: you leave home after conscientiously applying your protections, convinced of doing well. However, an interaction between two current products could form a potentially harmful cocktailreducing their effectiveness and weakening the skin without being really aware.
When two protections neutralize
Behind this gesture of logical appearance hides an unexpected interaction between two products yet designed to protect the skin. Some ingredients present in anti-mosquito repellents, such as Deet, can interact with UV filters contained in solar creams.
A study published by the CNRS in March 2025 confirms this: applied after sunscreen, a repellent can reduce the efficiency of UV protection significantly. If the skin seems protected, it can actually be exposed more quickly to the effects of the sun, especially in the event of prolonged exposure.
Why the sequence poses a problem
Superimposing two products rich in active ingredients can also increase the chemical load on the skin. Some repellents contain alcohol or solvents which, combined with heat, perspiration and friction of clothes, can weaken the skin barrier. Result: more sensitive, more reactive skin, and sometimes subject to redness or itching.
In children or sensitive skin, this uncontrolled sequence can even cause more marked skin reactions. Especially since these gestures are often repeated several times a day, without taking the time to question their compatibility.
Good gestures for without compromise protection
It is generally advisable to apply sunscreen first, on clean and dry skin. Wait fifteen minutes Allows UV filters to adhere to the skin well. It is only after this period that a repellent can be applied, by limiting the risk of interaction.
During the day, after swimming or strong perspiration, it is better to slightly clean the skin with a soft wipe or a fogger before starting the application : sunscreen first, then repellent then, always respecting a time of break between the two.
This routine requires a little rigor, but it remains the best option To guarantee effective protection, without overloading the skin unnecessarily.
