Facial peeling: what it is, types and acids

Facial peeling: what it is, how it works and what types exist

A facial peel is a dermoesthetic procedure that applies a chemical solution to facial skin to produce controlled exfoliation. The acid dissolves the bonds between cells in the stratum corneum—the outermost layer of the epidermis—causing damaged layers to shed and activating the skin's natural repair response: increased production of collagen, elastin and new cells. The result is skin that is more uniform, radiant and with fewer imperfections.

Unlike cosmetic exfoliation, which works only on the surface, a medical peel can reach different depths of skin depending on the acid used, its concentration and the exposure time.

Summary

• A facial peel is a controlled chemical exfoliation that removes damaged skin layers and stimulates cell regeneration.
• They are classified as superficial, medium and deep according to the skin layer they reach.
• The acid, its concentration and contact time determine the depth and results.
• Superficial peels require virtually no recovery; deep ones require strict medical supervision.
• Not everyone is a candidate: pregnant women, recent users of isotretinoin and skin with active infections should avoid them.

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How a facial peel works

The applied acid breaks the intercellular bonds (desmosomes) of the stratum corneum, causing a controlled injury. The body interprets this injury as a signal to accelerate cell renewal: damaged superficial layers shed and are replaced by new skin, while in deeper layers, collagen and elastin synthesis is activated.

The process follows three phases:

1. Application and penetration. The professional applies the solution to clean, degreased skin. The depth of penetration depends on the type of acid, its pH, concentration and the number of layers applied.
2. Neutralization or removal. Some acids (such as glycolic) require neutralization with sodium bicarbonate or water; others (such as salicylic) are self-limiting and are simply removed with water.
3. Regeneration phase. In the following days, the skin begins the process of peeling and reconstruction. Duration varies from hours (superficial peels) to weeks (deep peels).

Types of peeling by depth

Superficial peel

Acts exclusively on the epidermis. Uses alpha-hydroxy acids (AHA) such as glycolic or lactic acid, or beta-hydroxy acids (BHA) such as salicylic, in low to moderate concentrations. Improves texture, uneven tone, mild acne and fine lines. Recovery is minimal: mild redness that disappears in 1-3 days. Suitable for most skin types, including dark skin with proper preparation.

Medium peel

Penetrates beyond the epidermis to the papillary dermis (the upper portion of the dermis). The most common agent is trichloroacetic acid (TCA) at 15-35%, alone or in combination (TCA + Jessner solution, TCA + 70% glycolic acid). Treats fine to moderate wrinkles, superficial acne scars, solar dyschromia and resistant melasma. Recovery lasts 5-7 days with visible peeling, redness and hypersensitivity.

Deep peel

Reaches the reticular dermis. Performed with phenol (Baker-Gordon formula) and requires cardiac monitoring, sedation or anesthesia. Treats deep wrinkles, severe photoaging and marked scars. Recovery is prolonged (2-4 weeks of intense peeling) and the risk of complications—permanent hypopigmentation, scars, cardiac toxicity—is significantly higher. It is contraindicated in skin types IV-VI due to the high risk of dyschromia.

Comparison of acids used in facial peeling

Mandelic acid deserves special mention: its molecule is larger than glycolic acid, which allows it to penetrate more slowly and with less irritation. This makes it an excellent option for sensitive skin and dark skin types (IV-VI), where the risk of postinflammatory hyperpigmentation is greater.

What to expect during a facial peel

Before the procedure. The professional evaluates skin type, conditions to be treated and clinical history. It is common to discontinue topical retinoids 3-7 days before (depending on peel depth) and, in dark skin, initiate a preparation regimen with hydroquinone or kojic acid weeks prior to reduce the risk of hyperpigmentation.

During application. The skin is cleansed and the acid is applied with gauze, brush or cotton. The sensation varies depending on depth: a superficial peel produces mild tingling or burning that lasts minutes; a medium peel generates more intense heat sensation; a deep peel requires anesthesia. The session lasts between 15 and 45 minutes depending on the protocol.

After the procedure. With superficial peels, skin may appear slightly pink and begin to peel subtly the next day. With medium peels, peeling usually starts between day 2 and 4, with visible sheets peeling off over 5-7 days. With deep peels, skin forms crusts and the healing process can extend several weeks. In all cases, strict sun protection (SPF 30+ minimum) is mandatory during and after recovery.

Who is a facial peel suitable for

A facial peel can benefit people with:

• Uneven texture or dull skin
• Fine lines and superficial wrinkles
• Hyperpigmentation, sun spots or melasma
• Mild to moderate active acne or superficial acne scars
• Photoaging (accumulated sun damage)
• Actinic keratosis (premalignant lesions, treated with medium or deep peel under medical supervision)

The type of peel and recommended acid depend on individual diagnosis. A superficial peel can be performed every 2-4 weeks for maintenance; a medium peel is spaced every 3-6 months; a deep peel is usually performed only once.

Who should avoid a facial peel

There are absolute and relative contraindications:

Absolute contraindications:

• Active infection in the area to be treated (active cold sores, bacterial or fungal infections)
• Current or recent use of isotretinoin (recommended to wait at least 6-12 months after discontinuing)
• Pregnancy and breastfeeding (due to lack of safety evidence and potential systemic absorption of certain acids)
• Open wounds or compromised skin barrier
• Known allergy to any component of the solution

Relative contraindications (require caution and adaptation):

• Skin types IV-VI: superficial and some medium peels are safe with proper preparation. Deep phenol peels are contraindicated due to the high risk of hypopigmentation and hyperpigmentation.
• Recent use of topical retinoids (discontinue 3-7 days before, or 2-3 weeks in dark skin)
• Recent sunburn
• History of abnormal scarring (keloids, hypertrophic scars)
• Use of photosensitizing medications (doxycycline, certain chemotherapy agents)
• Autoimmune diseases or immunosuppression

The professional evaluates each case to select the safest acid, concentration and protocol.

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Frequently asked questions

What is a facial peel?

A facial peel is a controlled chemical exfoliation that uses acidic solutions to remove damaged skin layers from the face and stimulate regeneration. The acid dissolves the bonds between dead cells in the stratum corneum, causing peeling that reveals new skin that is more uniform and radiant. Depending on the acid and its concentration, the peel can be superficial (epidermis only), medium (to papillary dermis) or deep (reticular dermis). Superficial peels are quick procedures with minimal recovery, while deep peels require medical supervision and weeks of healing.

How many types of facial peels exist?

Facial peels are classified into three depth levels: superficial, medium and deep. Superficial peels use AHA or BHA (glycolic, salicylic, lactic, mandelic) and act only on the epidermis. Medium peels use TCA at 15-35% or combinations such as Jessner + TCA and reach the papillary dermis. Deep peels use phenol and penetrate to the reticular dermis. Each level treats different conditions: from uneven texture and mild acne (superficial) to deep wrinkles and severe photoaging (deep). The choice depends on diagnosis and patient skin type.

Does a facial peel hurt?

Superficial peels produce mild tingling or burning that lasts a few minutes and do not require anesthesia. Medium peels generate a more intense heat sensation, which can be described as moderate itching during application; some protocols use a fan or cold air to improve comfort. Deep phenol peels do require local anesthesia, sedation or general anesthesia, as the sensation is significantly more intense. In all cases, the main discomfort occurs during application and resolves quickly once the acid is removed.

How often can you have a facial peel?

Frequency depends on depth. Superficial peels can be repeated every 2-4 weeks, allowing for series of 4-6 sessions for cumulative results. Medium peels are spaced every 3-6 months to allow complete dermal regeneration. Deep phenol peels are generally performed only once in a lifetime per treated area, given the level of remodeling they produce. Exceeding recommended frequency increases the risk of skin sensitization, hyperpigmentation and barrier damage.

What acid is best for acne?

Salicylic acid is the most indicated for active acne because, being a lipid-soluble BHA, it penetrates within the sebaceous follicle, dissolves excess sebum and clears pores from within. It also has anti-inflammatory and antibacterial properties. For superficial acne scars, glycolic acid or medium concentration TCA offer better results by stimulating collagen remodeling. Mandelic acid is a useful alternative in dark skin prone to acne, as it combines comedolytic action with lower risk of postinflammatory hyperpigmentation.

Can you have a facial peel on dark skin?

Yes, superficial and some medium peels are safe in skin types IV-VI when proper preparation is performed. Mandelic acid and salicylic acid are especially well tolerated in dark skin due to their lower irritation potential. The key is to prepare the skin beforehand—with depigmenting agents and strict sun protection—and avoid deep phenol peels, which carry a high risk of permanent hypopigmentation in dark skin types. An experienced professional adjusts the acid, concentration and number of layers to minimize the risk of postinflammatory hyperpigmentation.

How long does it take for skin to recover after a peel?

Recovery varies depending on depth. A superficial peel produces mild redness and subtle peeling that resolves in 1-3 days, allowing you to resume normal activities almost immediately. A medium peel causes visible peeling that begins between day 2 and 4, with sheets of skin shedding over 5-7 days; redness may persist 1-2 weeks. A deep phenol peel involves crusting, significant swelling and a 2-4 week healing process, with residual redness that can last months. Rigorous sun protection is mandatory in all cases.

What is the difference between peeling and exfoliation?

Exfoliation is a broad term that includes any method to remove dead cells from the skin surface—from home-made scrubs to brushes and low-concentration acids in serums. A peel is a professional procedure that uses acids at controlled concentrations to produce deeper and more uniform exfoliation, capable of reaching not only the epidermis but also the dermis. The key difference lies in depth, intensity and supervision: a medical peel generates a tissue repair response that at-home cosmetic exfoliation cannot match.

Can I have a facial peel if I am pregnant?

Not recommended. Although evidence on systemic absorption of all acids is limited, the precautionary principle prevails. Certain agents such as high-concentration salicylic acid and TCA lack sufficient safety data during pregnancy. Hormonal changes of pregnancy also make skin more reactive, increasing the risk of hyperpigmentation and adverse reactions. The recommendation of organizations like the AAD is to postpone any chemical peel until after delivery and breastfeeding.

Does a facial peel remove spots?

Peels are one of the most effective treatments for hyperpigmentation. Superficial peels with glycolic or mandelic acid gradually lighten mild spots by accelerating the turnover of melanin-laden keratinocytes. TCA at medium concentrations effectively treats solar lentigines and resistant melasma, although the latter may require a combined approach (peel + topical depigmentants + strict sun protection). Results depend on the type of spot, its depth (epidermal vs. dermal) and adherence to post-treatment care, especially daily sun protection.

Is a facial peel or microneedling better?

They are complementary treatments, not mutually exclusive. Chemical peeling works from the surface inward by dissolving skin layers; it is especially effective for texture, hyperpigmentation and acne. Microneedling creates vertical microchannels that stimulate collagen production from the dermis, being more effective for deep acne scars, pores and mild laxity. Many protocols combine both (in alternating sessions) to achieve superior results. Individual choice depends on the main problem to be treated and skin type: microneedling is often safer in dark skin for concerns that would require medium or deep peeling.

What care do I need after a facial peel?

Sun protection is the most important care: SPF 30+ broad spectrum, reapplied every 2 hours of exposure, for at least 2-4 weeks. Avoid scratching or peeling off skin sheets, as this can cause scars and hyperpigmentation. Use a sulfate-free gentle cleanser and a barrier-repairing moisturizer. Discontinue retinoids, home-use AHA/BHA, active vitamin C and physical exfoliants until skin is completely regenerated (1-2 weeks for superficial, 3-4 weeks for medium). Avoid intense exercise, saunas and chlorinated pools for the first 48-72 hours on medium and deep peels.