Comparison
Biological comparison
This compares mechanisms and evidence profiles. It is not a ranking, a recommendation, or a safety assessment.
Glycolic acid only
- Formation of the cornified envelope
Shared pathways
- No shared curated pathways
L-Ascorbic acid only
- Collagen biosynthesis and modifying enzymes
- Detoxification of reactive oxygen species
- Melanin biosynthesis
Glycolic acid
C2H4O3 · Exfoliant
Glycolic acid is the smallest alpha hydroxy acid. Its effects are strongly pH- and concentration-dependent and are chiefly described at the level of corneocyte adhesion.
Targets
- Kallikrein related peptidase 7 (KLK7) — modulates (low confidence)
- Corneodesmosin (CDSN) — associated with (medium confidence)
L-Ascorbic acid
C6H8O6 · Antioxidant
L-ascorbic acid is vitamin C: a water-soluble reducing agent and an essential cofactor for the prolyl and lysyl hydroxylases that mature collagen.
Targets
- Prolyl 4-hydroxylase subunit alpha-1 (P4HA1) — activates (high confidence)
- Procollagen-lysine 5-dioxygenase (PLOD1) — activates (high confidence)
- Tyrosinase (TYR) — inhibits (low confidence)
- Sodium-dependent vitamin C transporter 2 (SLC23A2) — targets (medium confidence)
Evidence engine
Strong
Multiple independent human studies point in the same direction.
Skinceptor Evidence Index
73
experimental · of 100
This index is a research-navigation aid describing how much evidence exists and how it was produced. It is not a medical safety score, an efficacy guarantee, or a clinical recommendation.
Study composition
- Human3
- Total studies
- 3
- Human studies
- 3
- Largest sample
- 41
- Range
- 1996–2018
Index breakdown
- Study design quality70% × 28%
Mean design weight across curated studies (meta-analysis 1.0, RCT 0.9, other human 0.7, review 0.45, animal 0.35, in-vitro 0.25).
- Human evidence share100% × 22%
Proportion of curated evidence measured in people rather than cells or animals.
- Evidence volume63% × 14%
Log-scaled count of curated studies, so volume alone cannot dominate the score.
- Largest sample size54% × 12%
Log-scaled largest reported sample size across curated human studies.
- Replication100% × 12%
Independent human studies, capped at three; one study is never treated as replicated.
- Recency60% × 7%
Linear decay over a twenty-year window from the most recent curated publication.
- Source traceability0% × 5%
Share of curated studies with a verified PMID or DOI in this dataset.
Insufficient comparable evidence for quantitative synthesis.
Evidence engine
Moderate
Some human evidence exists, but replication or sample sizes are limited.
Skinceptor Evidence Index
58
experimental · of 100
This index is a research-navigation aid describing how much evidence exists and how it was produced. It is not a medical safety score, an efficacy guarantee, or a clinical recommendation.
Study composition
- Human1
- Randomised controlled trial1
- In-vitro3
- Review2
- Total studies
- 7
- Human studies
- 2
- Largest sample
- 19
- Range
- 1991–2020
Index breakdown
- Study design quality46% × 28%
Mean design weight across curated studies (meta-analysis 1.0, RCT 0.9, other human 0.7, review 0.45, animal 0.35, in-vitro 0.25).
- Human evidence share57% × 22%
Proportion of curated evidence measured in people rather than cells or animals.
- Evidence volume95% × 14%
Log-scaled count of curated studies, so volume alone cannot dominate the score.
- Largest sample size43% × 12%
Log-scaled largest reported sample size across curated human studies.
- Replication67% × 12%
Independent human studies, capped at three; one study is never treated as replicated.
- Recency70% × 7%
Linear decay over a twenty-year window from the most recent curated publication.
- Source traceability14% × 5%
Share of curated studies with a verified PMID or DOI in this dataset.
Insufficient comparable evidence for quantitative synthesis.