Quick Comparison
| EGF (Epidermal Growth Factor) | Glycolic Acid | |
|---|---|---|
| Typical Concentration | Concentrations vary by product (typically measured in ppm or sh-oligopeptide-1 percentage). Applied once or twice daily. Best used after procedures or on aging skin. Apply before oils/occlusives. Store in refrigerator for stability. | Daily use: 5-10% at pH 3-4. Weekly peel: 10-30%. Professional peel: 30-70%. Start with 5% every other night. Increase concentration/frequency gradually. Always use SPF — AHAs increase sun sensitivity by up to 50%. Buffered formulations are gentler than free acid. |
| Application | Topical (serum, cream, ampoule). Apply to clean skin. Temperature-sensitive — some products require refrigeration. | Topical (toner, serum, peel, cleanser). Leave-on products are more effective than wash-off. Apply to dry skin at night. |
| Research Papers | 10 papers | 9 papers |
| Categories |
Mechanism of Action
EGF (Epidermal Growth Factor)
EGF binds EGFR/ErbB1 on keratinocytes and fibroblasts, triggering dimerization and autophosphorylation. Activates MAPK/ERK (Ras-Raf-MEK-ERK) and PI3K/AKT pathways, promoting proliferation, migration (actin reorganization, focal adhesion turnover), and differentiation. Upregulates cyclin D1, inhibits p27. Stimulates fibroblast collagen types I/III and hyaluronic acid via HAS2. In wound healing, accelerates re-epithelialization via keratinocyte migration and reduces scarring via TGF-beta modulation. For anti-aging, promotes cellular renewal and extracellular matrix production. Theoretical cancer concern from EGFR's growth role — topical EGF has not been shown to penetrate to basal layer or systemic circulation significantly.
Glycolic Acid
Glycolic acid disrupts ionic bonds between corneocytes (dead skin cells) in the stratum corneum by chelating calcium ions and lowering the calcium concentration at desmosomal junctions. This weakens corneodesmosome integrity and activates endogenous proteases (kallikrein 5 and 7), accelerating desquamation. At higher concentrations, glycolic acid penetrates the viable epidermis and dermis, where it stimulates keratinocyte differentiation and upregulates transforming growth factor-beta (TGF-β) signaling in fibroblasts. This promotes glycosaminoglycan (GAG) synthesis, type I and III collagen production via procollagen gene expression, and elastin remodeling. Its small molecular size (76 Da) and high water solubility give it the deepest penetration of any AHA. The exfoliation also improves barrier function over time by promoting proper corneocyte maturation and reducing stratum corneum compaction.
Risks & Safety
EGF (Epidermal Growth Factor)
Common
Very well-tolerated.
Serious
Theoretical concern about promoting growth of pre-existing skin cancers (unproven but debated).
Rare
Mild irritation.
Glycolic Acid
Common
Stinging, redness, peeling, sun sensitivity. Over-exfoliation damages the skin barrier.
Serious
Chemical burns from professional-strength peels without proper protocol.
Rare
Scarring from improper high-concentration use.
Full Profiles
EGF (Epidermal Growth Factor) →
A signaling protein that stimulates cell growth, proliferation, and differentiation. In skincare, EGF promotes wound healing, skin renewal, and collagen production. Originally used in medical wound care and post-laser recovery, it has become popular in Korean skincare for anti-aging. It is one of the few growth factors with evidence for topical skincare efficacy.
Glycolic Acid →
The smallest and most penetrating alpha-hydroxy acid (AHA). Derived from sugarcane, glycolic acid exfoliates by dissolving the bonds between dead skin cells on the surface, revealing smoother, brighter skin underneath. It is the most studied AHA with robust evidence for improving texture, fine lines, hyperpigmentation, and overall skin radiance. The gold standard chemical exfoliant.