Chemical peeling – how it works, acids and product ideas
Chemical peels are one of the most effective methods for stimulating natural skin renewal in a targeted manner. Unlike mechanical peels, they are based on the controlled action of acid-based active ingredients that can act on different levels of the epidermis. With the right selection and application, structure-improving, clarifying and regenerating effects can be achieved without unnecessarily irritating the skin.
The active principle of chemical peels is based on the ability of selected acids to modulate the intermolecular bonds in the stratum corneum. This targeted action loosens the binding substance between the horny layers, leading to controlled desquamation. Not only the percentage concentration of the acid plays a central role here, but also physicochemical properties such as dissociation behaviour, molecule size and the resulting pH value.
AHA – alpha hydroxy acids
Alpha hydroxy acids (AHA) are water-soluble and act predominantly in the upper epidermis. They improve the skin structure, promote moisture retention and can visually refine the complexion.
Glycolic acid
- Molar mass: approx. 76 g/mol
- pKa: approx. 3.8
Glycolic acid has the smallest molecular size in the AHA spectrum and therefore penetrates particularly well. This can lead to an intensive exfoliating effect.
Lactic acid
- Molar mass: approx. 90 g/mol
- pKa: approx. 3.9
Slightly milder than glycolic acid. It also has hydrating properties and can support the skin’s natural moisture retention.
Mandelic acid
- Molecular weight: approx. 152 g/mol
- pKa: approx. 3.4
Due to its larger molecular size, it penetrates more slowly and is suitable for more sensitive skin types.
Citric acid
- Molecular weight: approx. 192 g/mol
- pKa₁: approx. 3.1
- pKa₂: approx. 4.8
Citric acid is tribasic, which gives it a more complex effect. It is less penetrative, but can effectively exfoliate the upper cell layer while stabilising the pH value of the formulation.
Pyruvic acid
- Molar mass: approx. 88 g/mol
- pKa: approx. 2.5
Pyruvic acid is technically a keto-carboxylic acid derivative with a strong exfoliating effect. It has a superficial to medium-depth effect and is suitable for intensive exfoliation concepts in low concentrations.
BHA (beta hydroxy acids)
Beta hydroxy acids are fat-soluble and particularly suitable for skin types with high sebum output or a tendency to clogged pores.
Salicylic acid
- Molar mass: approx. 138 g/mol
- pKa: approx. 2.97
Due to its lipophilicity, salicylic acid can penetrate the sebaceous canal, dissolve sebum and at the same time has a slight anti-inflammatory effect. This makes it a key ingredient for targeted exfoliation formulations.
PHA – Polyhydroxy acids
Polyhydroxy acids are larger molecules and have a gentler effect than AHAs. They are ideal for sensitive skin and can also provide moisturising effects.
Lactobionic acid
- Molecular weight: approx. 358 g/mol
- pKa: approx. 3.8
Gluconolactone
- Molecular weight: approx. 196 g/mol
- pKa: approx. 3.6
Due to their large molecular structure, both PHAs are particularly gentle on the skin and offer antioxidant benefits that synergistically enhance each other.
Controlling factors for chemical peels
The depth and effectiveness of a chemical peel is determined by several factors:
- Acid type and concentration: Depending on their structure and concentration, acids have a superficial to medium-depth effect.
- pH value: A low pH value increases the free acid fraction and thus the activity.
- Exposure time: Longer exposure times enhance the effect, but not always proportionally.
- Skin condition: Sensitive or barrier-sensitive skin requires milder concepts (e.g. PHA).
A professional product formulation must precisely balance these parameters in order to achieve the desired effects without causing irritation.
In modern cosmetic practice, a variety of innovative product concepts have become established in the field of exfoliation, combining specifically tailored exfoliating effects with a high level of application comfort.
Innovative cosmetic products in the exfoliation sector
- 1. Hydrating AHA serum with controlled release: Combines glycolic acid, lactic acid and PHA in low concentrations to achieve a daily exfoliating effect without compromising the barrier.
- Multifunctional BHA rolling exfoliating gel: A gel with salicylic acid and organic surfactants that combines mechanical and chemical exfoliation when applied – ideal for blemish-prone skin.
- Mild PHA exfoliating tonic: A water-based tonic with gluconolactone and lactobionic acid that gently loosens dead cells while moisturising – particularly suitable for sensitive or barrier-sensitive skin.
- Overnight AHA Booster Mask: A mask with a higher concentration of citric and pyruvic acid complex for intensive overnight renewal. It contains barrier-strengthening lipids to reduce irritation.
- Dual-Layer Peeling Essence: An innovative concept with separate phases – a water-free acid phase (concentrated AHA/BHA) and a hygroscopic serum phase. When shaken, the peel is activated and provides targeted exfoliation plus moisture.
Advantages and limitations of chemical peels
A well-formulated chemical peel can:
- Support skin renewal
- Smooth the skin’s texture
- Even out pigmentation irregularities
- Refine pores
At the same time, it requires technical expertise, as incorrectly chosen concentrations or formulation errors can lead to irritation, barrier damage or pigmentation changes. Professional development and safety testing are therefore crucial.
Product claim map – chemical peeling
- AHA-based peeling products (glycolic acid, lactic acid, mandelic acid, citric acid, pyruvic acid)
Core function: exfoliation and skin renewal
Primary claims:
- Supports natural skin renewal
- Refines the complexion
- Smoothes the skin surface
- Promotes an even appearance
- Improves skin radiance (‘glow effect’)
Secondary claims:
- Helps to gently remove dead skin cells
- Supports the skin structure
- Optimises the absorption of subsequent care products
- Ensures a fresher skin feeling
Sensory claims
- Noticeably smoother skin
- Immediately perceptible freshness
- Visibly refined skin texture
Claim nuances according to acid
- Glycolic acid: intensive exfoliation, improves texture
Lactic acid: exfoliating and moisturising
- Mandelic acid: gentle exfoliation, also suitable for sensitive skin
- Citric acid: clarifying, skin-refining, pH-regulating
- Pyruvic acid: intensively renewing, for demanding exfoliation concepts
2.BHA-based exfoliating products (salicylic acid):
Core function: pore clarification and sebum control
Primary claims:
- Clarifies the pores
- Supports a clearer complexion
- Helps reduce clogged pores
- Regulates excess skin shine
Secondary claims
- Supports skin balance
- Promotes a more even complexion
- Particularly suitable for blemished or oily skin
Sensory claims
- Clarified skin feeling
- Less oily shine
- Fresh, clean skin perception
Positioning
- Ideal for combination and oily skin
- Suitable for cosmetic anti-blemish concepts (without medical acne claims)
3. PHA-based exfoliating products (gluconolactone, lactobionic acid)
Core function: Gentle exfoliation and skin comfort
Primary claims:
- Gentle skin renewal
- Particularly skin-friendly
- Suitable for sensitive skin
- Supports the skin barrier
Secondary claims:
- Moisturises
- Has a balancing effect
- Supports a smooth skin feel
Sensory claims
- Gentle exfoliation without burning
- Pleasant, soothed skin feel
- No feeling of tightness
Positioning
- Sensitive skin lines
- Post-treatment care
- Introduction to chemical exfoliants
4. Combined AHA/BHA/PHA products
Core function: Multi-level exfoliation
Primary claims:
- Works on multiple levels of the skin’s surface
- Combines gentle and effective exfoliation
- Supports a visibly even complexion
Secondary claims
- Balanced exfoliating effect
- Suitable for different skin needs
- Modern acid technology
Marketing claims (permitted):
- ‘Multi-acid complex’
- ‘Next-generation exfoliating formula’
- ‘Balanced acid system’
5. Product form-specific claim examples
Exfoliating serum
- Highly concentrated care
- Targeted exfoliation
- Light texture with fast absorption
Exfoliating tonic/liquid
- Daily skin refinement
- Prepares the skin for skincare products
- Refreshing exfoliating care
Overnight exfoliating mask
- Intensive skin renewal overnight
- Supports regeneration while you sleep
- Visibly smoother complexion in the morning
Exfoliating gel/rolling exfoliator
- Combines chemical and mechanical exfoliation
- Immediately visible skin smoothing
- Pleasant application with massage effect
Claim notes (important for safety and legal reasons):
Permissible/relatively unproblematic:
‘supports’, ‘promotes’, “helps”, ‘improves the appearance’
Avoid/risky:
‘treats’, ‘heals’, “therapies”, ‘acne-healing’, ‘anti-inflammatory in the medical sense’
Conclusion on chemical peels
A chemical peel is a powerful tool in cosmetic skin care based on biochemical and physical-chemical principles. By selecting the right combination of effective acids – from classic AHAs to BHAs and gentle PHAs – it is possible to create application-specific products that are both modern and well tolerated.
Innovative chemical peel products require a thorough understanding of acid chemistry, precise formulation work and a keen sense of efficacy, skin compatibility and regulatory requirements. This is exactly where Cosmacon comes in.
Cosmacon develops tailor-made chemical peeling concepts – from gentle PHA formulations to powerful multi-acid systems. We accompany projects from the selection of active ingredients to recipe development and stability assessment to marketable implementation – always with a focus on safe, effective and cosmetically acceptable solutions.
For those who want to get to market faster, Tojo Cosmetics also offers immediately available white label products in the exfoliation sector. These ready-to-use formulations enable rapid market entry and can be customised as needed.
Whether you are looking for a customised new development or an immediately available white label solution, Cosmacon and Tojo Cosmetics create modern chemical peeling products with substance, structure and market potential. Just ask us!
Literature:
Medical Beauty – Science & Research, Issue 06/2025, article ‘Chemical Peels – Peelings under the microscope’, pages 14–19