Retinol

Three names, many steps

Retinol, retinal and retinoic acid belong to the retinoid family. In the skin, retinol can be converted to retinal and then to retinoic acid. This last form participates in the regulation of the activity of certain genes by binding to cellular receptors. Applying a precursor therefore amounts to providing a molecule that the skin must still transform before this signaling step.

Retinal is one step closer to retinoic acid than retinol. This helps to understand its benefit, but does not allow you to calculate a simple equivalence between two bottles. The amount that penetrates, the transformations in the skin, the vehicle of the product and its stability also come into play. A retinal formula therefore does not automatically become superior to any retinol formula because it has one less step.

An action on the epidermis

The epidermis is constantly renewing itself: its cells are born in the deeper layers, evolve upwards, then participate in the protective surface layer. Retinoids influence this process of proliferation and differentiation. Over time, this action can contribute to a more even texture. It is different from a scrub which mechanically removes surface cells, even if both treatments can give the impression of smoother skin.

Work on human skin has observed in particular an increase in the thickness of the living epidermis after application of retinol. This does not mean that the skin immediately becomes more resistant to everything: at first, dryness and irritation can, on the contrary, disrupt its comfort. Visible peeling is therefore not a measure of benefit. You can achieve improvement without going through a phase of severely peeling skin.

What's going on around collagen

Beneath the epidermis, the dermis contains a network of fibers which contributes to the strength and mechanical properties of the skin. Collagen is one of them. Its balance changes with aging and exposure, particularly solar exposure. Retinoids act on mechanisms involved in this matrix; this is one of the reasons why their interest goes beyond the simple softening effect of a cream on the surface.

Experimental studies conducted with retinol on human skin find changes in markers associated with collagen production and the activity of fibroblasts, the cells that participate in this production. These observations make clinical improvements plausible, without promising the same result to each user. A biological marker that increases in a biopsy does not directly translate into the same percentage of fewer wrinkles.

Real results, but dependent on the formula

Clinical trials of retinol provide encouraging results on fine lines and certain signs of skin aging. Their scope remains linked to the product studied, the duration, the participants and the comparison method. The data on a drug like tretinoin are not sufficient to demonstrate the effectiveness of a cosmetic that contains another molecule. This is why the note retains a useful, but progressive and variable benefit.

Retinol is also a tricky ingredient to keep in a formula. Analyzes of commercial products show the importance of its stability during storage; So showing a percentage doesn’t tell the whole story. Packaging, other ingredients and storage conditions matter. Promises of encapsulation or gradual release may be of technical interest, but they do not replace an evaluation of the finished product.

Why tolerance is part of the result

A routine that is too aggressive can produce the opposite of the desired effect: redness, discomfort and pigmentation irregularities after irritation, especially on skin that marks easily. Simultaneously increasing concentration and frequency is therefore not a shortcut. The best rhythm is that which allows the treatment to continue without maintaining inflammation; less frequent application may be a suitable choice rather than a failure.

Finally, any change in the appearance of the face is not the result of retinol. Dehydrated skin may especially need a cream, persistent acne may need appropriate treatment, and an unusual spot may need an examination. The treatment finds its place when the objective is consistent with what it can provide: a gradual improvement in the quality of the surface and certain fine lines, within a routine that you enjoy keeping.