AHA (alpha-hydroxyacides). Under this name are grouped together natural fruit acids – including citric, glycolic, lactic and malic acids, as well as gluconolactone – which are incorporated into beauty creams to improve the appearance of aged skin. Used daily, they would accelerate the natural process of exfoliation and help regenerate the dermis.^{7, 8, 9} Research suggests that to achieve tangible results, you need a minimum of 8% AHA in a product as well as a pH between 3,5 and 5 (for better absorption). The degree of exfoliation therefore depends on the AHA concentration of the product and its pH. Most over-the-counter products, however, contain low amounts of AHA and their impact on the appearance of the skin is limited. Note that the use of dermatological products containing AHA concentrations higher than 10% (up to 70%) is only done under the advice of a professional. The AHAs in most commercial beauty products are synthetic, but many natural products are made from real fruit acids.

Side effects. Use with caution: Side effects can be serious and are still being researched. AHAs are acids, and therefore irritants, and can cause swelling, discoloration, rashes, itching and bleeding as well as excessive exfoliation and severe redness; it is therefore necessary to test the product first on a small region. In addition, they increase the photosensitivity of the skin, which requires the use of effective sunscreens on a continuous basis (note: in the long term, this increased photosensitivity can lead to skin cancer). According to a preliminary study by the Food and Drug Administration, photosensitivity would return to normal a week after stopping treatment.¹⁰

 DHEA (déhydroépiandosterone). On 280 people between 60 and 79 years old who used DHEA daily for a year (dose: 50 mg), the researchers observed a reduction in certain features of aging, especially in the skin (especially in women): increase in sebum production, better hydration and improved pigmentation.¹⁶

Side effects. DHEA is still little known and presents risks. See our DHEA file.

 Retinol. This scientific term refers to natural molecules of vitamin A. The majority of research focuses on the active form of retinol (see retinoic acid, above). A study suggests that retinol stimulates the formation of collagen in the skin (after applying a cream of 1% vitamin A for seven days).¹¹ However, over-the-counter beauty creams contain small amounts of retinol, given its high toxicity (see on this subject vitamin A); the results concerning wrinkles and other manifestations of aging are real, but necessarily minimal. Side effects are still possible. A study points out that this natural form of vitamin A is less irritating to the skin than its derivative, retinoic acid.¹²

 Green tea. We know the benefits of green tea (Camellia sinensis) that we drink, but some beauty products also offer extracts for topical application. Based on preliminary scientific observations, it appears that the polyphenols it contains can prevent damage from UVB rays in fair-skinned people.¹³

 Vitamin C in topical application. Topical preparations containing 5% to 10% vitamin C appear to improve the appearance of the skin. In several three-month clinical trials with placebo, in small groups, researchers were able to measure changes: reduction of wrinkles, improvement in the texture and color of the skin.¹⁴ Another research could measure an improvement in collagen.¹⁵

 Vitamin E in topical application. Many beauty products contain vitamin E, but research on their effectiveness in treating or preventing skin aging is inconclusive (despite the claims).¹⁷ Additionally, vitamin E can cause skin allergies.

 Acupuncture. In traditional Chinese medicine, there are treatments to stimulate energy which maintains the vitality of tissues. Specific techniques are also aimed at reducing fine lines and even expression lines, but also other skin conditions. Less marked than with medical interventions, some improvement appears after two or three sessions; a complete treatment lasts 10 to 12 sessions, after which it is necessary to resort to maintenance treatments. Depending on the conditions of the person, practitioners evoke several results of acupuncture: stimulation of certain organs, increase in blood circulation in the region concerned, increase in yin energy which moistens, relaxation of the muscles whose contraction causes a good part of wrinkles. With some exceptions, these treatments do not cause side effects.

 Exfoliation. Thanks to very slightly abrasive products or natural or chemical acids (AHA, BHA, glycolic acid, etc.), this treatment frees the skin of dead cells, which accelerates cell renewal. The products that you apply yourself or those used in beauty practices are comparable. The change in the appearance of the skin is relatively small and temporary.

 Moisturizers. Dry skin doesn’t cause wrinkles, it just makes them more noticeable. Moisturizers do not treat wrinkles (except those that contain the ingredients mentioned above), but make the skin look better temporarily and play an important role in skin maintenance. Creams and lotions contain all kinds of natural products – such as yam, soy, coenzyme Q10, ginger or algae – which can have a beneficial effect on the skin, but at the moment there is no reason to believe that they can modify its structure. For more information, see our Dry Skin sheet.

 Lemon juice. It may be, according to some sources, that a regular application of a few drops of lemon juice on the spots of senile lentigo attenuate them and even make them disappear. We do not know of any scientific research to this effect.

 Massage. Massage helps restore the skin’s natural hydration and release toxins from the lymphatic system. In addition, some manipulations are designed to relax facial muscles and reduce wrinkles. The effects are short lived, but a regular program of facial massage can help keep the skin looking good.

 Facial treatment. A complete facial treatment in a beauty salon usually includes an exfoliation, a hydrating mask and a facial massage, three treatments that are beneficial for the skin, although their impact is minor and temporary. Beware of too strong exfoliators which can cause complications.

 Vitamin supplements. At this time, it is not believed that ingesting vitamins provides increased benefits to the skin, as the body only allocates a certain amount of vitamins to the skin, regardless of the amount ingested.¹⁸