Topical NMN, a form of vitamin B3 in skin creams and serums, is marketed to smooth wrinkles, restore firmness and even out skin tone. Cell and animal studies support the idea, but the only published human data show small one-month gains without a comparison product, and nearly all evidence comes from sellers. Safety looks reassuring so far. For people with a thorough skincare routine, a plausible but largely unproven addition. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Standardized facial photography | No established target; track change from own baseline | Documents visible wrinkles, tone and texture |
| Wrinkle depth (3D skin imaging) | No established target; track % reduction from own baseline | Objective wrinkle and pore measure |
| Skin hydration (corneometer) | No universal target (device-specific units); track rise from own baseline | Surface water content |
| TEWL (transepidermal water loss, tewameter) | No established target; lower than or equal to own baseline | Barrier function and early irritation signal |
| Skin elasticity (cutometer R2) | No established target; higher than own baseline | Firmness and elastic recovery |
| Melanin index (colorimeter or imaging) | No established target; lower in treated spots than own baseline | Tracks pigment and tone evenness |
| Full-skin examination | No new or changing lesions | Screens for pre-malignant or malignant change |
Cadence: Baseline, then photographs and instrumental readings at 4 weeks, 12 weeks, then every 3–6 months while the product is used; full-skin examination yearly, or every 6 months with a history of skin cancer. Irritation persisting beyond 1 week, or any new or changing lesion, prompts stopping and reassessment.