Glycolic peel: intense stimulation

Author: Andrey Petrovich – chief physician of the Center for Aesthetic Medicine, assistant at the Department of Clinical Pharmacology of Zaporozhye Medical University, surgeon (Ukraine, Zaporozhye).

Among anti-aging technologies, peelings occupy a place of honor. With the help of damage and negative stimulation, it is possible to force the skin to renew itself. Therefore, there are now a large number of different peeling systems on the professional cosmetics market. Let's consider the possibilities of classic glycolic peeling in the treatment of skin aging.

Spectrum of action

Glycolic acid (GLA) is the smallest alpha hydroxy acid that has balanced multi-vector effects: damage, penetration and stimulation. In the stratum corneum, it destroys the connections between corneocytes and thereby enhances their exfoliation. With this effect, the peeling will be microscopic, invisible to the eye.

Therefore, glycolic peeling does not deprive the client of social adaptation, and he calmly endures the post-peel period without changing his lifestyle.

Glycolic acid acquires a keratolytic effect only at high concentrations (70% or more) and low pH (1.0 or lower) with prolonged exposure. The keratolytic effect of glycolic acid is rarely used, only in the presence of hyperkeratosis on seborrheic skin. A thick stratum corneum, impregnated with sebum, retains acid on the surface for a long time, which allows for a keratolytic effect. In other cases, glycolic acid, with such a high acidity, quickly penetrates deep into the skin, reaching the papillary layer of the dermis, where it can cause an inflammatory reaction.

Glycolic peels are designed primarily to perform superficial chemical damage to the skin. But the effectiveness of glycolic peeling is not limited to the damaging effect on the stratum corneum - this is only one of its functions. The full spectrum of effects of glycolic acid is as follows:

1. Damage;
2. Penetration (penetration);
3. Irritation;
4. Stimulation of keratinocytes;
5. Stimulation of fibroblasts.

Damage

Glycolic acid primarily destroys the desmoid bonds between keratinocytes. The mechanism of action is natural for the epidermis. Normally, the skin itself produces hydroxy acids - lactic and others, which take part in the process of physiological exfoliation. Glycolic acid, by and large, enhances the natural exfoliation of the horny envelopes in small scales (2-4 horny envelopes), so there is no visible peeling in the post-peeling period.

According to histological examination, glycolic peeling reduces the thickness of the stratum corneum by 50%, but at the same time makes it denser and more elastic.

When performing an effective (the entire stratum corneum is damaged) superficial glycolic peeling, the stratum corneum barrier is damaged and the TEWL increases. Its recovery occurs after 4 days, which are called the post-peeling rehabilitation period.

Penetration

Although GHA is the smallest of all alpha hydroxy acids, it effectively disrupts desmoid bonds, allowing it to penetrate very deeply, reaching the dermis in therapeutic concentrations. To a large extent, it was the ability to penetrate deeply that provided GLA with leadership among other hydroxy acids. In addition, GLA is a good conductor for other substances.

Irritation

Glycolic acid irritates nerve receptors, stimulating the release of both inflammatory mediators and regeneration stimulants. Therefore, carrying out a classic glycolic peeling for acute inflammation and on sensitive skin can first cause an aggravation of the process and only after that a positive therapeutic effect.

Stimulation of keratinocytes

Glycolic acid has a direct stimulating effect on keratinocytes. In this case, both mitotic and synthetic activity are stimulated. According to histological examination, peeling with glycolic acid leads to an increase in the layer of living cells by 50%, and the overall thickness of the epidermis increases by 20%. Also, with the help of instrumental research, an increase in the moisture content of the epidermis is recorded.

Fibroblast stimulation

Glycolic acid stimulates the synthetic activity of fibroblasts, increasing the synthesis of collagen, elastin and matrix components. Studies (histological and in vitro) show that synthesis depends on the concentration and pH of GlK.

The implementation of the above effects occurs at different times. Thus, damaging and irritating effects are realized immediately during the procedure, and the stimulating effect will be delayed for 2–4 weeks (depending on the capabilities of the body). Naturally, effective stimulation of the dermis (fibroblasts) is possible only when GLA penetrates the basement membrane in therapeutic concentrations.

Options and combinations

What parameters of the peeling solution realize one or another effect of glycolic acid?

1. The concentration of glycolic acid (marked in % AHA) determines the strength of cell stimulation (depending on the depth of penetration) and the partially damaging effect of the solution. Concentration: 20–25% – low, 30–40% – medium, 50–70% – high.
2. The acidity of the peeling solution is expressed in pH units (the lower the value, the higher the acidity). Acidity determines the depth of penetration of glycolic acid, the strength of irritation and most of the damaging effects. At very high acidity, GLA acquires a direct keratolytic effect. Acidity: pH 3.0–2.0 units. – low, pH 2.0–1.5 units. – average, pH 1.5–1.0 units. – high, pH below 1.0 units. - very high.

As you can see, the same property of glycolic acid is determined by different parameters of the peeling solution. Therefore, a comprehensive assessment of the strength of the peeling solution is necessary, which includes the synergism of acidity and concentration.

Classic peeling solutions are presented in a parallel increase in the concentration of GLA and acidity (decrease in pH) of the peeling solution:

1. ANA concentration less than 35% and pH above 2.0 are weak;
2. ANA concentration 50–35% and pH 2.0–1.5 are average;
3. ANA concentration 50–70% and pH 1.5–1.0 are strong;
4. An AHA concentration of 70% and a pH below 1.0 are super strong.

In addition to the above, other combinations of concentration and acidity of peeling solutions are possible.

Features of the impact

Skin aging is always associated with a decrease in the activity of fibroblasts and, as a consequence, a decrease in the synthesis of extracellular molecules: hyaluronic acid, collagen, elastin, etc. This in turn leads to thinning of the skin, a decrease in its elasticity and turgor and, as a result, to its sagging. To activate fibroblasts under such conditions, very intense stimulation is necessary.

To realize a powerful stimulation of fibroblasts, it is necessary to obtain a high and uniform concentration of glycolic acid in the dermis and a significant decrease in pH. Technically, achieving the goal is not so difficult - take a peeling solution of 70% AHA with a pH of less than 1.0 and leave it for 8-10 minutes, but it is necessary to take into account the skin reaction and its biological resource. Unprepared skin is simply not able to withstand such a powerful impact. This is precisely where the complexity of the task lies. At the same time, we have to face a vital paradox: the higher the stage of skin aging, the greater the level of damage required to obtain a good result. However, the higher the stage of skin aging, the less damage it can withstand.

What to do? An integrated approach is required in preparing for procedures, precision in performing a damaging procedure and ensuring intensive recovery after it.

Preparation and final care

Pre-peeling preparation plays an important role in the effectiveness of intensive stimulation of the dermis.

Pre-peel preparation refers to the use of home remedies with glycolic acid to adapt the skin to intense acid exposure. But in our case, we will consider pre-peeling preparation as a set of measures that allow us to prepare aging skin for intensive stimulation with a 70% glycolic acid solution with a pH below 1.0.

At home, we prescribe creams containing glycolic acid in an AHA concentration of 8–12% at a pH of 3.5. The products are applied 1-2 times a day depending on skin type, level of aging and its reaction to glycolic acid. We cancel them on the day of peeling and within 4 days after peeling. We use serums under the cream with glycolic acid, depending on the existing problems. For dry skin, we apply serums containing hyaluronic acid, and for sagging skin, serums containing retinol.

During the post-peeling period, we use emollient creams containing hyaluronic acid, reparants, antioxidants, etc.

An effective combination

Before starting the peeling course, we carry out a biorevitalization procedure using native hyaluronic acid preparations. The first glycolic peeling is carried out 10 days after the biorevitalization procedure. Depending on the skin type and its reaction to pre-peel preparation with topical products, we choose a weak or medium peeling solution. With each subsequent procedure, we increase the exposure time, and when the exposure time exceeds 10 minutes, we switch to a stronger peeling solution.

The combination of peeling and biorevitalization procedures can be presented in the following order.

1. First biorevitalization with native hyaluronic acid and the beginning of pre-peel preparation.
2. First peeling with a weak peeling solution.
3. Second biorevitalization with the preparation of hyaluronic acid ester ACP.
4. Second peeling with a medium peeling solution, exposure time – 5–8 minutes.
5. Third peeling with a medium peeling solution, exposure time - more than 10 minutes.
6. Third biorevitalization with the preparation of hyaluronic acid ester ACP.
7. The fourth peeling with a strong peeling solution, exposure time – 5 minutes.
8. Fifth peeling with a strong peeling solution, exposure time - more than 8 minutes.
9. The sixth peeling with a super-strong peeling solution, exposure time - 5-8 minutes.

If there is a need to enhance the therapeutic effect on the skin, we use medium TCA peeling.

Thus, to obtain the desired result with intense stimulation of the dermis, the use of classic glycolic peeling in anti-aging programs requires a special complex effect and an individual approach.

Source: KOSMETIK international journal, No. 4(38), 2009, pp. 72-74