Retinol - answers to your most frequently asked questions according to a doctor and analyses by BeautyDecoders.

The questions that come back again and again

Retinol is the benchmark anti-aging active ingredient, studied for decades, first for acne and then for anti-aging. Certain questions keep cropping up - here are the answers, point by point. For the basics on this active ingredient, see the complete guide to retinol.

Retinoids are a family of molecules derived from vitamin A. From the weakest to the most powerful: retinol esters convert to retinol, which converts to retinal, which in turn converts to retinoic acid. The latter is the only active form: the most potent, but only available by prescription (tretinoin), and few people can tolerate it. All other forms must undergo one or more transformations to reach this structure and take effect.

Retinol esters are the gateway: they require three transformations and are 10 to 20 times less potent than retinoic acid. They are marketed as «pro-retinol», emphasizing their tolerability without mentioning their low efficacy. They remain an option for skin that cannot tolerate retinol, or for fragile areas (eye contour, neck). In the INCI list, they are recognized as retinol propionate, palmitate or acetate. Granactive retinol, on the other hand, may act more directly, making it more effective than esters but less irritating than retinol.

If the skin barrier is healthy, we can start directly with retinol: the most famous retinoid, with an excellent efficacy-tolerance ratio, provided it is introduced gradually. It requires two transformations to reach the retinoic acid stage. Retinal, on the other hand, requires only one, and therefore acts more quickly. But beware: a retinal product is not necessarily more powerful than a retinol serum, depending on concentration.

Yes, retinol is effective: dozens of clinical studies, with follow-ups ranging from one month to several years, demonstrate this. It's the reference active ingredient for wrinkles, fine lines, brown spots and post-acne marques, and a good option for blemishes and excess sebum. Its three main actions:

A misconception. The epidermis does indeed become thinner during the tolerance phase, due to accelerated cell renewal. But in the long term, by boosting collagen and elastin production, retinol stimulates overall skin growth: the dermis redensifies and the epidermis plumps up. The final effect is therefore the opposite of slimming.

The most common mistake is to start off too strong. Dosage, frequency and type of retinoid depend on skin type, condition and tolerance. Patience and progress are the watchwords. If the skin barrier is damaged, don't start: repair it first, then go very gradually. Start with a concentration of 0.2 or 0.3 % (aqueous formula for normal to oily skin, richer for dry skin). If all goes well, test 0.5 %, then 1 % after a few months.

Practical detail: retinol is unstable in pipette bottles and can degrade with use, giving the illusion of good tolerance when it is no longer active. Prefer hermetically sealed pump bottles, or discard the serum after 3 months. Finally, avoid starting in summer: retinol is photosensitizing, and a daily SPF 50 is essential. For more details, see the guide how to get started with retinol.

On healthy skin that tolerates retinol perfectly, there's no need to stop it before botox or hyaluronic acid injections. For laser hair removal, on the other hand, it's better to be cautious: stop retinol 3 to 4 days beforehand, on perfectly healthy, non-irritated skin. In all cases, these procedures require a medical consultation.

Since cell renewal takes 30 days, the first effects on texture, blemishes and imperfections appear between one and three months. Most studies deliver their conclusions after two to three months. Anti-ageing performance, on the other hand, is really visible between 6 months and a year: take a photo before you start and another at six months, because the results are subtle on a day-to-day basis but obvious over time.

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