How 5% Glycolic Acid Cream Works
Glycolic acid 5% cream functions as an alpha-hydroxy acid (AHA) peeling agent that chemically exfoliates the skin by breaking down intercellular bonds in the stratum corneum, promoting cell turnover and surface skin renewal. 1
Mechanism of Action
Glycolic acid works through multiple pathways:
Chemical exfoliation: As the smallest alpha-hydroxy acid molecule, glycolic acid penetrates the skin to disrupt keratinocyte adhesion, causing desquamation of dead surface cells and promoting regeneration of the epidermis 2, 3
pH-dependent antibacterial activity: At lower pH levels (3.0-3.5), glycolic acid exhibits potent antibacterial effects against Cutibacterium acnes by disrupting bacterial cell membranes, with concentrations as low as 0.2% showing efficacy when properly formulated 4
Keratolytic enhancement: When combined with other agents like salicylic acid, glycolic acid acts synergistically to enhance penetration and efficacy of co-administered treatments 2
Clinical Applications and Efficacy
For acne treatment:
- Glycolic acid 5-15% in home-use formulations provides significant resolution of comedones, papules, and pustules with minimal side effects 5
- The treatment rejuvenates skin texture, reduces follicular pore size, and brightens skin appearance 5
- Consistent, repetitive application is necessary for improvement of acne scars and deeper cystic lesions 5
For facial flat warts:
- A 5% glycolic acid formulation demonstrated complete clearance in a small case series of 15 children with facial plane warts, though the evidence quality is limited (Level 3, Strength D) 1
- An open study combining 2% salicylic acid with 15% glycolic acid achieved 100% cure rates within 8 weeks for recalcitrant facial flat warts 1
For pigmentation and photoaging:
- Glycolic acid enhances the efficacy of depigmenting agents when used in combination regimens for melasma 6
- Serial peels with higher concentrations (20-70%) provide superior results compared to daily low-strength applications for atrophic scarring 3
Application Guidelines
Standard home-use protocol:
- Apply once or twice daily to clean, dry skin 2, 5
- Avoid the eye area during application 2
- Follow with a gentle moisturizer once absorbed 2
- Mandatory daily broad-spectrum sunscreen use is essential, as glycolic acid increases photosensitivity 7, 2
Tolerance optimization:
- If bothersome dryness or peeling occurs, reduce application frequency 2
- Use a gentle, non-medicated cleanser between applications 7
- Avoid concurrent use of other keratolytic or photosensitizing agents during the initial adjustment period 7
Important Safety Considerations
Critical warnings:
- For external use only; if product enters eyes, rinse thoroughly 2
- The 5% concentration is well-tolerated for home use, but higher concentrations (20-70%) used in professional peels carry increased risk of irritation and require supervision 3
- Contraindicated on the face with higher-strength salicylic acid paints due to risk of chemical burns 1
Common side effects to monitor:
- Dry skin, peeling, scaling, and flaking 7
- Erythema and burning sensation 7
- These effects are generally mild at 5% concentration and resolve with reduced application frequency 2, 5
Comparative Effectiveness Context
While glycolic acid 5% is effective for superficial skin concerns, the evidence shows that for more significant pathology like actinic keratoses, 5-fluorouracil 5% cream ranks at the top of topical treatment efficacy 1. Glycolic acid peels (70%) can be used as an adjunct to enhance 5-FU penetration for actinic keratoses, but this represents a different clinical application than routine 5% home-use formulations 8.