Myth or reality: do blemishes disappear in the sun?

The skin thickens to protect itself from UV rays

When exposed to the sun, the skin activates natural defence mechanisms. The thickening of the outermost layer contributes to this protection. However, it has no lasting effect on the skin’s balance.

The sun dries out the skin without regulating sebum production in the long term

The sun promotes water loss from the skin’s surface. The skin may then appear less shiny, giving the impression that sebum production is regulated. This is in fact a case of skin dehydration, and the effect is only temporary.

Pores and spots appear less visible

Thicker skin and a tanned complexion can make spots and pores appear less visible. But in reality, this merely alters the skin’s appearance without having a lasting effect on the causes of blemishes.

A tan masks redness without treating blemishes

The pigmentation caused by tanning visually reduces redness, which can give the impression of smoother skin. However, this effect is essentially visual.

The sun masks scars but promotes hyperpigmentation

Sun exposure can also create the illusion of reducing acne scars by temporarily evening out the complexion, but this effect is misleading. In reality, UV rays stimulate melanin production and promote hyperpigmentation, which can permanently darken acne scars and make them more visible over time. Appropriate sun protection is therefore essential to ensure proper healing and help reduce the appearance of these marks.

The improvement observed is usually temporary

Consequently, as sun exposure decreases, the skin gradually returns to its normal function. In skin prone to blemishes, spots may then reappear.

Thickening of the skin’s outermost layer: When exposed to UV rays, the skin reacts by producing more cells on the surface. The outermost layer then becomes denser, which strengthens the skin’s protection but slows down the natural shedding of dead cells.

Skin dehydration and a gradual imbalance in sebum production: Sun exposure promotes the evaporation of water from the skin’s surface⁵. To maintain its comfort, the skin may produce more sebum, which can lead to the appearance of blemishes and spots after exposure.

Impaired skin barrier and hidden inflammation⁴: The skin barrier helps the skin to remain protected and well-hydrated. Under the effect of the sun, it can become weakened, making the skin drier and more sensitive.

After prolonged exposure, the skin seeks to compensate for the imbalances caused by the sun. With its surface dried out, it attempts to restore its moisture balance by stimulating sebum production. At the same time, the temporary thickening of the stratum corneum slows down the natural shedding of dead skin cells. This combination promotes pore blockage and creates conditions conducive to the reappearance of blemishes. This mechanism, often referred to as the ‘rebound effect’, is particularly noticeable in acne-prone skin. As the skin rehydrates after the summer, sebum production increases, whilst the weakened pores become blocked more easily. Inflammation may then gradually reappear, signalling the return of skin imbalances. To protect the skin from blemishes, sun cream is therefore essential³.

What effects does the sun have on the skin? In the short and long term?

In the short term, the sun mainly alters the appearance of the skin. In the longer term, repeated and inadequately protected exposure can exacerbate dehydration, weaken the skin barrier, increase blemishes and make certain marks more visible. Repeated exposure also contributes to accelerated skin ageing and can permanently impair the skin’s proper functioning.

How do you choose a suitable sun protection product for blemish-prone skin?

1. Choosing a suitable sun protection product for blemish-prone skin means effectively protecting the skin without disrupting its balance. Broad-spectrum protection, covering both UVA and UVB rays, is essential to limit both sun-induced inflammation and the thickening of the stratum corneum – two mechanisms involved in the blockage of pores.

2. Texture is also a key factor. Lightweight, non-comedogenic and non-occlusive formulas are preferable so as not to increase sebum production. Overly rich textures can, on the contrary, contribute to the recurrence of blemishes, particularly after sun exposure.

3. Finally, the sun protection factor (SPF) should be chosen according to the intensity of sun exposure rather than skin type. An SPF of 30 to 50 is still recommended, provided the formula is well tolerated and gentle on the skin barrier. When chosen carefully, sun protection thus helps prevent the rebound effect and maintain more balanced skin after the summer.

Myth or reality: do blemishes disappear in the sun?

The improvement in the appearance of blemishes observed in the sun is mainly due to temporary visual effects. An even tan creates the illusion of smoother, more uniform skin, temporarily concealing spots and imperfections. This improvement is therefore more cosmetic than physiological.

What is true

The sun alters the appearance of the skin, visually reducing certain redness and temporarily drying out the skin’s surface. Under the effect of UV rays, the skin thickens slightly, which can make blemishes less visible in the short term. However, this sensation of ‘clearer skin’ is temporary.

What is false

Sunlight does not have a lasting effect on the mechanisms involved in the development of blemishes and does not help regulate sebum production in the long term. On the contrary, sun exposure can lead to a rebound effect, with increased sebum production after the summer. UV rays can also promote inflammation and weaken the skin barrier.

Food for thought

According to a study in the *Journal of Cosmetic Dermatology*, 80 per cent of patients with acne developed brown marks following unprotected sun exposure. This post-inflammatory hyperpigmentation transforms temporary spots into long-lasting pigmented marks, explaining why sun protection remains essential (8).

We offer products formulated to support the skin whilst it is exposed to the sun, taking into account the specific needs of blemish-prone skin:

Mineral Sun Milk SPF 30

This non-comedogenic sun milk with an invisible finish effectively protects the skin from UVA and UVB rays thanks to a 100% naturally derived mineral filter. Its formula combines zinc oxide with an extract of Karanja, known as pongamol, to ensure a high level of protection. Water-resistant, its milky texture spreads easily and leaves the skin soft and velvety, delicately scented with notes of Monoï.

Discover the Mineral Sun Milk SPF 30

Mineral Sun Balm SPF 50

This non-comedogenic balm is suitable for combination to oily skin, or skin prone to acne. Apply all over the face and body. Reapply your sun protection every two hours and after swimming.

Discover the Mineral Sun Balm SPF 50

Mineral Sun Stick SPF 50

Apply this non-comedogenic stick evenly to the sensitive areas you wish to protect (nose, cheekbones, ears, forehead, lips, recent scars, tattoos, etc.). Reapply your sun protection every two hours, and after swimming or drying yourself off.

Discover the Mineral Sunscreen Stick SPF 50

Organic Aloe Vera Gel

Thanks to its moisturising and soothing properties, it is particularly well suited to relieving the burning sensation and discomfort experienced by problem skin following sun exposure. It can be used undiluted on the skin and hair and is suitable for all skin types. Remember to store this product in the fridge between uses.

Discover the Organic Aloe Vera Gel

Skin prone to blemishes may be more sensitive to imbalances caused by sun exposure. It is recommended that you adapt your skincare routine before and after sun exposure, avoid overly harsh products, and steer clear of anything likely to increase skin sensitivity – such as exfoliating too frequently or using certain highly concentrated products, which can make the skin more sensitive.

In summer, the sun puts the skin under a lot of strain, particularly if it is prone to blemishes. The key is to support the skin’s barrier without overstimulating sebum production: opt for gentle cleansing once or twice a day, avoid harsh active ingredients and boost hydration with lightweight yet restorative formulas. Appropriate, non-comedogenic sun protection, combined with limiting the time spent in the sun, helps to gently support the skin without disrupting its natural mechanisms.