Chemical Peels Explained — Types, Benefits, and What to Expect

Last updated: 5 March 2026

Chemical peels are among the oldest and most well-established treatments in dermatology, with historical records of acid-based skin treatments dating back to ancient Egypt. Today, chemical peels remain a cornerstone of modern aesthetic medicine, offering versatile solutions for a wide range of skin concerns — from superficial pigmentation and fine lines to deep acne scarring and photodamage. This evidence-based guide explains the science behind chemical peels, the different types available, what to expect during treatment, and how to achieve the best possible results.

What Is a Chemical Peel? Understanding the Mechanism

A chemical peel involves the controlled application of an acid solution to the skin, causing exfoliation and subsequent regeneration of the treated layers. The fundamental principle is controlled injury — by removing damaged outer skin layers in a precise, predictable manner, the body’s wound healing response produces new, healthier skin with improved texture, tone, and clarity.

The depth of the peel — and therefore the intensity of results — depends on several factors: the type of acid used, its concentration, the pH of the solution, the duration of application, and whether the peel is neutralised or self-neutralising.

A comprehensive review by Soleymani et al. published in the Journal of Clinical and Aesthetic Dermatology (2018) classified chemical peels into three categories based on the depth of skin penetration.

Superficial (Light) Peels

Depth: Epidermis Only

Superficial peels target the outermost layer of skin (epidermis) and are the gentlest option. They require no downtime and are suitable for most skin types and tones.

Common Superficial Peel Agents

• Glycolic acid (20-50%): An alpha-hydroxy acid (AHA) derived from sugar cane. The smallest AHA molecule, it penetrates easily and provides uniform exfoliation. Research by Sharad in Clinical, Cosmetic and Investigational Dermatology (2013) demonstrated significant improvement in photoaged skin after a series of glycolic peels.
• Salicylic acid (20-30%): A beta-hydroxy acid (BHA) that is lipophilic, meaning it penetrates into pores and is particularly effective for oily, acne-prone skin. A study in the International Journal of Dermatology (2019) found salicylic acid peels reduced active acne lesions by 47% after 3 sessions.
• Lactic acid (30-50%): A gentler AHA with additional hydrating properties, ideal for sensitive or dry skin types.
• Mandelic acid (30-50%): A larger-molecule AHA that penetrates more slowly, making it suitable for darker skin tones with lower risk of post-inflammatory hyperpigmentation.

What to Expect

Superficial peels cause mild tingling or stinging during application, lasting 2 to 5 minutes. Post-treatment, the skin may appear slightly pink for a few hours. Fine, mild flaking may occur over 2 to 3 days. Most patients require no downtime and can apply makeup the same day. A course of 4 to 6 treatments, spaced 2 to 4 weeks apart, is typically recommended for optimal results.

Medium-Depth Peels

Depth: Epidermis Through to Upper Dermis (Papillary Dermis)

Medium-depth peels create more significant injury, reaching into the upper dermis. They produce more dramatic results but require more recovery time.

Common Medium-Depth Peel Agents

• Trichloroacetic acid (TCA) 15-35%: The most versatile and widely used medium-depth peel agent. TCA causes protein coagulation (visible as white frosting on the skin) and produces reliable, predictable results. A study by Lee et al. in Dermatologic Surgery (2002) demonstrated significant improvement in fine wrinkles, dyspigmentation, and skin texture after TCA peels.
• Jessner’s solution + TCA (combination peel): Jessner’s solution (a mixture of lactic acid, salicylic acid, and resorcinol) is applied first to enhance TCA penetration uniformity. The Monheit technique, published in the Journal of Dermatologic Surgery and Oncology (1989), established this combination as the gold standard for medium-depth peeling.
• Glycolic acid 70% + TCA 35%: An alternative combination approach that provides uniform medium-depth penetration.

What to Expect

Medium-depth peels cause significant stinging and burning during application, typically lasting 3 to 5 minutes. The skin will appear red and may swell. Over 3 to 7 days, the treated skin will darken, form a crust, and peel off to reveal fresh, pink skin beneath. Full recovery takes 7 to 14 days, during which sun avoidance is essential. Results are visible once peeling is complete and continue to improve over 2 to 3 months as collagen remodelling occurs.

“Medium-depth peels occupy a valuable middle ground in our treatment repertoire. They offer significantly better results than superficial peels for concerns like moderate photoageing, acne scarring, and melasma, while avoiding the extended downtime and risk profile of deep peels. For many patients, they represent the optimal balance between efficacy and practicality.” — Dr. Priya Chen, Axiom Aesthetics

Deep Peels

Depth: Mid-Reticular Dermis

Deep peels penetrate to the mid-dermis and produce the most dramatic results. However, they carry higher risks and require careful patient selection and management.

Common Deep Peel Agents

• Phenol (Baker-Gordon formula): The classic deep peel agent. The Baker-Gordon formula, first described in 1962, combines phenol with croton oil, septisol, and distilled water. Research published in Plastic and Reconstructive Surgery has demonstrated that phenol peels can produce dramatic improvement in deep wrinkles, severe photoageing, and pre-cancerous lesions, with results lasting 10 to 20 years.
• TCA 50%+ (high-concentration): While TCA can be used at higher concentrations for deeper penetration, it is less predictable than phenol at deep levels and carries a higher risk of scarring.

Important Considerations for Deep Peels

Deep peels require cardiac monitoring during application, as phenol can cause cardiac arrhythmias when absorbed systemically. Recovery takes 2 to 4 weeks, with significant crusting, oozing, and swelling in the initial days. Deep peels carry a significant risk of permanent pigmentation changes and are generally not recommended for Fitzpatrick skin types IV-VI. Due to these factors, deep peels are less commonly performed today, with many practitioners opting for combination approaches or laser resurfacing as alternatives.

What Chemical Peels Can Treat

Chemical peels are effective for a broad range of skin concerns:

• Fine lines and wrinkles: Particularly perioral and periorbital lines
• Sun damage and photoageing: Including roughened texture, lentigines, and actinic changes
• Hyperpigmentation: Melasma, post-inflammatory hyperpigmentation, and age spots
• Acne and acne scarring: Active breakouts (superficial peels) and atrophic scars (medium-depth peels)
• Uneven skin tone and texture: Dullness, rough texture, and pore congestion
• Mild skin laxity: Through collagen stimulation in medium and deep peels

Chemical Peels and Skin of Colour: Special Considerations

Patients with darker skin tones (Fitzpatrick types IV-VI) can safely undergo chemical peels, but require careful consideration. A comprehensive review by Alexis et al. in Dermatologic Clinics (2020) highlighted the following guidelines:

• Superficial peels (glycolic acid, salicylic acid, mandelic acid) are generally safe for all skin types
• Pre-treatment with topical agents (hydroquinone 4%, tretinoin, vitamin C) for 2 to 4 weeks can reduce the risk of post-inflammatory hyperpigmentation
• Medium-depth peels should be used with caution and by experienced practitioners
• Deep peels are generally contraindicated in darker skin tones
• Salicylic acid and mandelic acid are preferred for acne treatment in skin of colour due to their lower risk of hyperpigmentation

Preparing for Your Chemical Peel

Proper preparation significantly improves outcomes and reduces complication risk:

1. Pre-peel skincare regimen (2-4 weeks prior): Your practitioner may recommend topical retinoids, alpha-hydroxy acids, and vitamin C to prime the skin and ensure more uniform acid penetration.
2. Sun protection: Strict SPF 50+ use in the weeks leading up to treatment. Tanned or sunburned skin should not be peeled.
3. Medication review: Certain medications (isotretinoin, photosensitising drugs) may need to be discontinued prior to treatment.
4. Antiviral prophylaxis: Patients with a history of cold sores should take antiviral medication (valaciclovir) starting 1 to 2 days before treatment to prevent herpes simplex reactivation.
5. Avoid waxing, threading, or laser hair removal in the treatment area for at least 1 week prior.

Post-Peel Care and Recovery

Aftercare is critical to ensuring optimal results and minimising complications:

• Gentle cleansing: Use a mild, non-foaming cleanser. Avoid scrubbing or picking at peeling skin.
• Moisturisation: Apply a gentle, fragrance-free moisturiser frequently. Ceramide-based products are particularly beneficial during the healing phase.
• Sun protection: SPF 50+ broad-spectrum sunscreen is essential for a minimum of 4 to 6 weeks post-peel. UV exposure during healing can cause permanent hyperpigmentation.
• Avoid active ingredients: Retinoids, AHAs, BHAs, and vitamin C should not be used until the skin has fully healed (typically 7 to 14 days for medium-depth peels).
• No swimming, saunas, or excessive sweating for 7 to 10 days post-medium-depth peels.

Potential Risks and Complications

While chemical peels have an excellent safety profile when properly administered, potential risks include:

• Post-inflammatory hyperpigmentation: More common in darker skin types. Usually temporary but can persist for months.
• Scarring: Rare with superficial and medium-depth peels; higher risk with deep peels, particularly if post-peel care is not followed.
• Infection: Bacterial or viral (herpes simplex reactivation). Prophylactic treatment minimises this risk.
• Prolonged erythema: Persistent redness lasting weeks to months, more common with deeper peels.
• Demarcation lines: Visible boundaries between treated and untreated skin, particularly with deep peels. Feathering technique minimises this risk.

Frequently Asked Questions

How many chemical peel sessions will I need?

This depends on the type of peel and your treatment goals. Superficial peels are typically performed in a series of 4 to 6 sessions, spaced 2 to 4 weeks apart, for cumulative improvement. A single medium-depth peel can produce significant results, though some patients opt for annual maintenance treatments. Deep peels are generally performed only once. During your consultation, we will recommend a treatment plan tailored to your specific skin concerns and goals.

Are chemical peels painful?

Superficial peels cause mild tingling or stinging that most patients find entirely tolerable. Medium-depth peels produce more significant burning and stinging, lasting 3 to 5 minutes, which can be managed with a handheld fan and ice. Deep peels are typically performed under sedation or with nerve blocks. At Axiom Aesthetics, we prioritise your comfort and will discuss pain management options during your consultation.

Can I have a chemical peel if I have sensitive skin?

Yes, with appropriate selection. Lactic acid and mandelic acid peels are specifically designed for sensitive skin types, providing gentle exfoliation with minimal irritation. Your practitioner will assess your skin sensitivity during consultation and may recommend a test patch before proceeding with full treatment.

How do chemical peels compare to laser resurfacing?

Both treatments achieve controlled skin removal and regeneration, but through different mechanisms. Chemical peels use acid solutions, while lasers use focused light energy. For mild to moderate concerns, results are often comparable. For deeper concerns, fractional CO2 laser resurfacing may offer more precise control of penetration depth. A study in Dermatologic Surgery (2019) found that patient satisfaction was similar for medium-depth peels and non-ablative fractional laser treatments. The choice often comes down to specific skin concerns, skin type, and practitioner expertise.

Will my skin peel visibly after treatment?

Superficial peels typically cause minimal visible peeling — often just mild flaking that can be concealed with moisturiser and makeup. Medium-depth peels produce more noticeable peeling over 3 to 7 days. Deep peels involve significant crusting and peeling over 7 to 14 days. We will provide detailed post-care instructions and schedule follow-up appointments to monitor your healing process.