Topical Nicotinamide Riboside Improves Skin Hydration and Redness: Clinical Findings
Objectives
To assess the irritation potential and short-term effects of topical NR administration on hydration, redness, glossiness, and skin-barrier measures.
Journal
Preprints
Key Outcomes
- NR alone produced little to no irritation after a single extended exposure, providing preliminary evidence that the tested NR materials were well-tolerated under the study conditions.
- In the RIPT tests, neither the water- or dry-form NR formulations were associated with evidence of allergic skin sensitization, providing further evidence of NR's tolerability.
- A single application of topical NR increased moisture in the outermost layer of the skin, with concentrations of 1.5% and higher showing the clearest effects.
- Topical NR was also associated with improvements in measures of skin redness and surface smoothness, with higher concentrations generally showing the clearest changes.
- TEWL decreased in a dose-dependent pattern, although the change was not statistically significant.
- Participants also reported perceived improvements in hydration, softness, smoothness, and redness.
Duration
- Part I: Single application under a patch for 48 hours
- Part II: 9 applications over about 3 weeks, followed by a 2-week break and a final application
- Part III: Single application, with assessments over 8 hours
Dose
- Part I: 50 or 100 mg of NR
- Part II: 0.5% NR in water or 0.5% NR in dry-form sachet delivery system
- Part III: 0.5-10% aqueous NR
Study Design
- Part I: Primary Dermal Irritation Test in 30 healthy participants
- Part II: Repeated Insult Patch Tests (RIPT) in 210 participants
- Part III: Randomized, participant-blinded, within-person efficacy testing in 62 healthy Chinese adults with normal, dry, or combination skin