Retinoids for skin aging are the only topical agents for which there are large controlled clinical trials to support their claims. Retinoids are a family of chemicals that are essentially just relatives of vitamin A. Some retinoids are found naturally in nature and in our diet, while others are purely synthetic compounds. The best-known of these is tretinoin (also known as trans-retinoic acid), but there are also many others, including less toxic, more selective and better-tolerated retinoids. Other forms include retinol, retinal, retinoic acid and retinol palmitate (although there is little evidence that the latter improves wrinkle depth or hyperpigmentation).
Tretinoin was first used in the seventies for the treatment of wrinkles and acne, and as research continued it became more widely used to repair sun-damaged skin, improve fine wrinkles and mottled sun spots, and smooth the surface of the skin. An anti-ageing legend was born.
Retinoids for skin aging have a good evidence base
Retinoids are still the only topical agents for which there are large controlled clinical trials that support their use in the repair of damage associated with ageing and sun exposure. This is why they are the most widely prescribed treatment for those conditions. Retinoids are best considered as pharmaceuticals. The most potent forms are used only on prescription; however, retinoids are also found in many cosmeceutical preparations, albeit generally in tiny concentrations or in ‘inactive’ forms.
Retinoids for skin aging work in much the same way as fillers
Retinoic acid is naturally present in our skin. All retinoids, natural and synthetic, either have a retinoic acid element as part of their chemical structure or get converted into retinoic acid by our skin’s chemical processes. Retinoic acid repairs the skin by binding to specific receptors. This sets off a chain of chemical signals that leads to the formation of new matrix and a coordinated reduction in pathways that contribute to matrix loss, including inflammation, DNA damage and oxidative stress. This slowly stretches the skin and fills out fine wrinkles and lines, in much the same way as fillers.
Retinoids for skin aging promote cell turnover
By stimulating skin cell turnover, retinoids also promote the shedding of old cells and the growth of new ones in the deeper layers of the skin, which then push upwards. This can improve the appearance and texture of the skin. Excess pigment production is also improved, giving the skin a more uniform appearance without the spots and blotchiness associated with ageing. Retinoids are able to significantly reverse the signs of ageing skin and restore a more youthful appearance. Retinoids may also have important effects in reducing the risk of skin cancers that are more common in ageing skin.
Impact of retinoids for skin aging varies with formulation
Retinoid compounds and formulations vary in their ability to get the active ingredient (retinoic acid) into our skin cells as they have very different potencies. Like tretinoin, some are super-potent and ready to go, but as a result also tend to be more irritating to the skin. Many women who use potent retinoids experience redness, flaking, sensitivity to sunlight and other side effects. This means potent retinoids must be used in low concentrations (usually between 0.02 percent and 0.05 percent) on prescription and only with regular medical supervision. By contrast, lower potency retinoids, like vitamin A (retinol), are often present in over-the-counter anti-ageing creams and lotions, and can be safely used in concentrations up to 0.5 percent.
Retinoids for skin aging will only work whilst being used
Although retinoids work well to restore youthful skin features, the signals that retinoids send to the skin will cease if we stop using them, and the skin starts ageing again. Skin practitioners will usually follow an initial treatment course with a long-term maintenance plan of retinoid application at a lower concentration, with lower potency retinoids or with less frequent applications.
Side effects of retinoids for skin aging
No irritation occurs with the use of retinol palmitate; however, retinol, retinal and retinoic acid must be introduced gradually into a homecare skincare routine, as they have the potential to cause some irritation (dryness, tightness, etc.). This allows the skin cells to gain tolerance to the more active retinoids in the skin.
Apply retinoids for skin aging in the evening
Retinoids are often used in the evening as exposure to UV radiation degrades their efficacy. However, retinoids can be used in the daytime as long as you use a broad-spectrum suncream and avoid excessive exposure to sunlight. The greater the dose, frequency, and potency of the retinoid, the greater the risk of skin irritation.
Avoid irritation with retinoids for skin aging
Newer formulations and modes of application that prevent retinoids from penetrating too deep into the skin can be used to reduce the risk of skin irritation, but do not completely prevent it. Treating only once daily, or even less frequently if troublesome irritation occurs, can also reduce side effects. Some practitioners use topical anti-inflammatories or hydrocortisone creams in combination in order to reduce or prevent irritation from initial retinoid treatments.
Natural compounds, such as gingko extracts, cola extract, beta-sitosterol and liquorice extract as glycyrrhetinic acid (which inhibits the cytokines that cause retinoid dermatitis) are also sometimes used in combination with retinoids to reduce skin irritation. It’s also worthwhile to use an appropriate moisturiser 30 to 60 minutes after the retinoid application. However, any irritation should only be temporary when first starting to use retinoids; if irritation persists stop use and seek medical guidance. Do similarly if the skin starts to flake.
Who shouldn’t use retinoids for skin aging
Women who are pregnant or planning to become pregnant are advised not to use retinoids, as some may have harmful effects in the developing baby (although the risk is remote as very little of the compound actually penetrates the skin).