The ingredient, explained
Ornithine
A primary study examines this ingredient in the specified preparation and setting.
Ingredient guide
What it is and what it does
Pentanoic acid, 2‚5-diamino-, -S--
About this ingredient: EU CosIng ingredient registry (via Open Beauty Facts taxonomy) ↗
- Skin conditioning
- A broad cosmetic role for maintaining skin condition. It does not identify a particular clinical benefit.
Function definitions: European Commission ingredient function definitions (SCCNFP/0299/00, pages 16 to 20) ↗
Registry functions describe possible formulation roles, not results for a finished product. A dictionary entry is not an approval or a safety assessment.
A closer look
What the research shows
Human oral research
Oral mixture improved skin elasticity and TEWL versus placebo in a pilot trial.
What this does not tell us
22 Japanese participants, oral mixture. No isolated ornithine effect; IGF-1 change is mechanistic and not proof of mediation.
Sources for this summary. PubMed 30513923 ↗
Research review checked Oct 1, 2026
Bounded review of local candidates, exact-name indexed primary journal/PubMed safety and topical searches; not a systematic review.
Ingredient research is not proof that a product containing this ingredient works.
Read the 1 selected study
Human oral research · n=22
Effects of Composite Supplement Containing Collagen Peptide and Ornithine on Skin Conditions and Plasma IGF-1 Levels-A Randomized, Double-Blind, Placebo-Controlled Trial. ↗
Marine drugs · 2018
Follow the formula
Products containing this ingredient
From the wider catalogue. Linked by the ingredient list, without an efficacy ranking.
Names and identifiers
Registry identity
Pentanoic acid, 2‚5-diamino-, -S--
- INCI name on ingredient lists
- ORNITHINE
- CAS registry number
- 70-26-8
- EC number
- 200-731-7
Sources for this ingredient record
- EU CosIng ingredient registry (via Open Beauty Facts taxonomy) ↗ · ODbL 1.0 (Open Beauty Facts database) · Recorded Aug 8, 2026