Ingredient intelligence
L-Ascorbic acid
Antioxidant · Ascorbic Acid · C6H8O6
L-ascorbic acid is vitamin C: a water-soluble reducing agent and an essential for the prolyl and lysyl hydroxylases that mature .
Any underlined term can be tapped for an everyday-English translation.
Molecular identity
- Formula
- C6H8O6
- Molecular weight
- 176.12 g/mol
- PubChem CID
- 54670067
- ChEBI
- CHEBI:29073
Biological targets
Prolyl 4-hydroxylase subunit alpha-1 (P4HA1)
high confidenceactivates · enzyme
Ascorbate is a required for prolyl hydroxylation.
UniProt P13674Procollagen-lysine 5-dioxygenase (PLOD1)
high confidenceactivates · enzyme
UniProt Q02809Tyrosinase (TYR)
low confidenceinhibits · enzyme
Reduction of intermediates reported ; not established as the dominant in skin.
UniProt P14679Sodium-dependent vitamin C transporter 2 (SLC23A2)
medium confidencetargets · transporter
UniProt Q9UGH3
How could this ingredient interact with biology?
Biological network
Ingredient → molecule → target → gene/protein → pathway → process → studied outcome. Relationship strength is drawn from the curated confidence tier; nothing is added to make the chain look complete.
drag to pan · hover to isolate a path · click a node for detail
4 lower-confidence relationships are hidden at this filter level. Use “Show more biology” to include them.
Text alternative for this network
- L-Ascorbic acid is molecule L-Ascorbic acid — high confidence
- L-Ascorbic acid is molecule Dehydroascorbic acid — high confidence
- L-Ascorbic acid activates Prolyl 4-hydroxylase subunit alpha-1 (P4HA1) — high confidence
- L-Ascorbic acid activates Procollagen-lysine 5-dioxygenase (PLOD1) — high confidence
- L-Ascorbic acid targets Sodium-dependent vitamin C transporter 2 (SLC23A2) — medium confidence
- Prolyl 4-hydroxylase subunit alpha-1 (P4HA1) encoded by P4HA1 — high confidence
- Procollagen-lysine 5-dioxygenase (PLOD1) encoded by PLOD1 — high confidence
- P4HA1 participates in Collagen biosynthesis and modifying enzymes — high confidence
- PLOD1 participates in Collagen biosynthesis and modifying enzymes — high confidence
- COL1A1 participates in Collagen biosynthesis and modifying enzymes — medium confidence
- P4HA1 participates in Detoxification of reactive oxygen species — medium confidence
- PLOD1 participates in Detoxification of reactive oxygen species — medium confidence
- COL1A1 participates in Detoxification of reactive oxygen species — medium confidence
- Collagen biosynthesis and modifying enzymes associated with Collagen biosynthesis — high confidence
- Detoxification of reactive oxygen species associated with Collagen biosynthesis — medium confidence
- Collagen biosynthesis and modifying enzymes associated with Oxidative stress response — medium confidence
- Detoxification of reactive oxygen species associated with Oxidative stress response — medium confidence
- Collagen biosynthesis studied in Studied for photoaging-related endpoints and pigmentation evenness — medium confidence
- Oxidative stress response studied in Studied for photoaging-related endpoints and pigmentation evenness — medium confidence
- Collagen biosynthesis studied in Formulation instability is a frequently reported limitation — high confidence
- Oxidative stress response studied in Formulation instability is a frequently reported limitation — medium confidence
Biological pathways
Collagen biosynthesis and modifying enzymes
high confidenceAscorbate-dependent hydroxylation steps required for stable triple-helix formation.
Reactome R-HSA-1650814
Detoxification of reactive oxygen species
medium confidenceAscorbate participates in cellular redox buffering.
Reactome R-HSA-3299685
Melanin biosynthesis
low confidencereduction of intermediates; limited translation to skin.
Gene Ontology GO:0042438
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.
Research timeline
How the evidence accumulated
1991
Ascorbate requirement for hydroxylation and secretion of procollagen
Reviewsample size unavailable · American Journal of Clinical Nutrition (review)
2002
Topical vitamin C and photoaging: a double-blind half-face study
Randomised controlled trialn = 19 · Dermatologic Surgery
2005
Ferulic acid stabilises a solution of vitamins C and E and doubles its photoprotection
Humann = 9 · Journal of Investigative Dermatology
2007
Ascorbyl glucoside stability and enzymatic release of ascorbic acid in skin models
In-vitrosample size unavailable · International Journal of Cosmetic Science
2012
Stability and skin delivery of ascorbyl phosphate derivatives
In-vitrosample size unavailable · International Journal of Cosmetic Science
2013
Stability of L-ascorbic acid in topical formulations
In-vitrosample size unavailable · International Journal of Cosmetic Science
2020
Vitamin C derivatives for facial hyperpigmentation: a narrative review
Reviewsample size unavailable · Journal of Cosmetic Dermatology (review)
Ingredient fingerprint
19 nodes · 37 relationships · seed "l-ascorbic-acid"
The fingerprint is a deterministic visual signature: ridge amplitude comes from the number of entities in each tier, node placement from identifier hashes, and opacity from confidence. Two ingredients can never produce the same figure unless their networks are identical.
Open in Biology as Art →Research
7 curated studies
Vitamin C derivatives for facial hyperpigmentation: a narrative review
Concludes that derivative-specific human evidence is thinner than for L-ascorbic acid, with conversion efficiency the main open question.
Limitations — Review of heterogeneous small studies; identifier not verified during curation.
Stability of L-ascorbic acid in topical formulations
Reported rapid oxidative degradation of L-ascorbic acid at neutral pH, mitigated by low pH and antioxidant co-formulation.
Limitations — Formulation chemistry only; no biological endpoints.
Stability and skin delivery of ascorbyl phosphate derivatives
Reported improved formulation stability for magnesium ascorbyl phosphate but slower and variable conversion to free ascorbate in skin models.
Limitations — Formulation and ex-vivo delivery only; no clinical endpoints.
Ascorbyl glucoside stability and enzymatic release of ascorbic acid in skin models
Reported greater aqueous stability than L-ascorbic acid and glucosidase-dependent release of free ascorbate in skin homogenates.
Limitations — Homogenate model may overstate in-vivo conversion; identifier not verified during curation.
Ferulic acid stabilises a solution of vitamins C and E and doubles its photoprotection
Reported improved formulation stability and increased measured photoprotection for a C/E/ferulic combination on human skin.
Limitations — Very small sample; surrogate photoprotection endpoints; industry-affiliated.
Topical vitamin C and photoaging: a double-blind half-face study
Reported improvement in investigator-assessed photoaging scores on the vitamin C treated side.
Limitations — Very small sample; identifier not verified during curation; formulation stability not reported.
Ascorbate requirement for hydroxylation and secretion of procollagen
Establishes ascorbate as an obligatory cofactor for prolyl and lysyl hydroxylases in collagen maturation.
Limitations — Nutritional/biochemical focus rather than topical cosmetic use.
Community evidence
Submitted by readers
Reader submissions appear here only after review. They are not part of the curated dataset and do not affect the Skinceptor Evidence Index.
No approved community submissions yet.
Sources
- PubChem 54670067Verified 2026-09-14
- UniProt P13674Verified 2026-09-14
- Reactome R-HSA-1650814Verified 2026-09-14