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Which sunscreen should you choose?

With a diverse range of sunscreens, choosing one can be complex. Your skin’s needs change with season, holiday destination, and phototype. How should you choose a sunscreen? Here are our recommendations.

Summary
Published June 19, 2025, updated on June 19, 2025, by Pauline, Chemical Engineer — 9 min read
Sun protection

Criterion No. 1: The time of year.

To choose your sunscreen, you must first consider the season, as UV intensity varies throughout the year. It is quantified by the UV index, a standardised scale ranging from 0 (low) to 11+ (extreme) that measures risk to the skin from sun exposure. The higher the index, the stricter the protection should be.

In summer, the UV index exceeds 7 or 8 and may reach 10 in some regions. This level of UV causes intense exposure between 11:00 and 16:00. During this period, use a sunscreen with SPF 50, which filters around 98% of erythema-causing UV. This protection prevents sunburn and limits long-term UV effects, such as photoageing, indicated by premature lines and brown spots.

In winter, UV index often falls below 3. An SPF 30 blocks 96.7% of erythemal UV and can suffice for daily use with brief exposure (commuting, short walks). This level of protection needs re-evaluation if undertaking activities at altitude, where UV intensity rises by 5% for every 1,000 metres of elevation and where snow reflection increases exposure. In such cases, SPF 50 becomes necessary, even in mid-winter.

Note : UVA rays are the primary cause of photoaging but play almost no role in SPF calculations. The PA rating measures protection against UVA. There are four categories: PA+, PA++, PA+++ and PA++++, the highest level.

Quantité d'UVA et d'UV érythémateux atteignant la surface de la Terre tout au long de l'année.
Amount of UVA and erythemal UV reaching the Earth’s surface throughout the year.
Source: Skin Cancer Prevention.

Criterion No. 2: The geographical area.

Geographical location influences ultraviolet intensity and therefore the required level of sun protection. Indeed, the UV index increases as one moves closer to the equator, where the sun’s rays strike the earth’s surface at a more perpendicular angle. Similarly, regions at altitude or with high reflectance, such as snow, sand or sea, increase skin exposure to UV.

In tropical and equatorial regions, the UV index exceeds 10 or 11 year-round, exposing skin to intense radiation in cloudy conditions. SPF 50 or 50+ with a water-resistant formulation offering enhanced UVA protection is imperative. In temperate regions, the UV index varies by season. In France, for example, it can reach 8 or 9 in summer but drop below 3 in winter. Prolonged exposure during holidays, hiking or outdoor sports should prompt the use of SPF 50 in summer at moderate latitudes, and at least SPF 30 in winter if reflection is significant.

It is also important to note that air pollution, more common in some urban or industrial areas, can alter UV penetration in the atmosphere. Depending on their density, fine particles can reduce the amount of UVB reaching the surface. A study in Beijing, a city often cited for high pollution levels, found that pollution can reduce UVB by 50% at ground level. While this might at first glance seem beneficial, it increases the proportion of more penetrating UVA reaching the surface. While the sunburn risk is lower in polluted environments, UVA-induced damage to collagen and elastin fibres and oxidative stress increase. Choosing a sunscreen that protects against UVA is advisable in large cities.

Indice UV moyen dans le monde en janvier et en juillet.
Average global UV index in January and July.
Source: VANICEK K. et al. UV index for the public. European Cooperation in Science and Technology-713 (1999).

Criterion No. 3: Your skin phototype.

The phototype indicates natural sensitivity to sunlight based on skin, eye, and hair colour. It affects the risk of sunburn, photoageing and UV-induced skin damage. There are six phototypes, I to VI, from lightest to darkest. Phototypes I to III (very fair to medium skin with light eyes and blonde or red hair) burn and develop little tan. High protection with at least SPF 50 is essential from the initial rays of sunlight, even in urban areas. Phototypes IV to VI (olive to dark skin with brown to black eyes and hair) have partial natural protection due to higher melanin levels in the skin. This pigment coats keratinocyte nuclei to form a shield that protects DNA from UV mutagenic and carcinogenic effects.

The average SPF of black skin is 13.4 compared with 3.4 for white skin.

However, this pigment barrier is not sufficient to protect people with dark skin, who also need to apply sunscreen, with an SPF of at least 30, contrary to common belief. A study of 55 individuals with darker skin types found that 74% had not used sunscreen, believing it was unnecessary. More prevention is needed for people with darker skin who may assume they are protected from the sun’s rays.

Temps nécessaire pour développer un coup de soleil selon le phototype.
Time needed to develop a sunburn based on phototype.
Source: VANICEK K. et al. UV index for the public. European Cooperation in Science and Technology-713 (1999).

Criterion No. 4: Your skin typology.

Each skin needs its own sunscreen. In addition to phototype, we recommend that you take into account the nature of your skin (dry, normal, combination or oily), a factor influencing the texture to choose. Dry skin, for example, has a fragile barrier due to low sebum production and benefits from a rich sunscreen with a high oil phase and relipidating and emollient ingredients. These nourishing textures improve comfort on dry skin and help maintain sun protection.

By contrast, oily or acne-prone skin should favour lightweight, non-occlusive formulations such as gels to prevent comedones. Some sunscreens for these skin types include mattifying agents. It is important to note that no sunscreen can be undetectable, as UV filters are lipophilic : they must be dissolved in the oily phase of the formula. This lipid phase is essential to ensure effective UV protection.

Beyond skin type, sensitivity matters. Some skin types are prone to redness, tingling, or irritation after applying certain UV filters, such as the para-aminobenzoic acid (PABA) or the oxybenzone, and this can worsen with added fragrances. Mineral filters, namely titanium dioxide and zinc oxide, offer alternatives for sensitive skin but can leave a white cast, which limits their use on darker phototypes. To check a sunscreen’s finish and tolerance, test the product on a small patch of skin, for example the inner elbow or wrist, leave it for 24 to 48 hours and observe any redness or irritation.

Good to know : We use only UV filters documented for both human safety and ecotoxicology.

Criterion No. 5: Your environmental sensitivity.

Choosing a sunscreen can also reflect an ethical or environmental concern. Some UV filters are under scrutiny for their potential impact on aquatic ecosystems, such as coral reefs. Among the most controversial are the octocrylene, oxybenzone and the octisalate. Some studies have shown these compounds can disrupt coral growth and reproduction, and cause bleaching by altering the symbiotic microalgae that support their survival. Although concentrations in bathing waters vary, several regions worldwide, such as Hawaii, Palau and the Virgin Islands, have banned or restricted filters deemed ecotoxic.

Individuals concerned about these issues can choose sunscreens with a reduced environmental impact.

Sources

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