Controlled destruction of the skin's outer layers for smoother, more evenly colored skin. Depth decides everything: the shallowest clear roughness, brown patches and acne marks in days; the deepest reshape skin structure for a decade but cost weeks of recovery and possible permanent color change. Evidence is strongest for pigment and precancerous sun spots; wrinkle gains are modest. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Fitzpatrick skin phototype | I–III for medium and deep peels; IV–VI superficial only unless test-spotted | Predicts rebound darkening |
| Glogau photoaging grade | II–III for medium peels; IV needs a deep peel or laser | Sets achievable depth and expectation |
| Electrocardiogram (ECG) and corrected QT interval | Sinus rhythm; QTc below 440 ms in men and 460 ms in women | Phenol provokes arrhythmia |
| Serum creatinine and eGFR | eGFR above 90 mL/min/1.73 m² | Phenol is cleared by the kidneys |
| ALT and AST | ALT 10–26 U/L in men, 8–22 U/L in women; AST 10–26 U/L | Phenol is conjugated in the liver |
| Glycated hemoglobin (HbA1c) | Below 5.4% | High blood glucose delays wound closure |
| Methemoglobin by co-oximetry | Below 1.5% | Resorcinol in Jessner's solution can raise it |
| Serum salicylate | Undetectable, below 2 mg/dL | Large-area salicylic acid peeling can cause salicylism |
| 25-hydroxyvitamin D | 40–60 ng/mL | Strict light avoidance during healing suppresses skin synthesis |
| Herpes simplex virus IgG serostatus | No established target value; serostatus and prophylaxis adherence are tracked instead | Identifies who is at reactivation risk |
Cadence: Review at 48–72 hours, 2 weeks, 6–8 weeks, then 3 and 6 months; thereafter every 6–12 months. Laboratory values repeated only for phenol peels, immediately after the procedure and at 24 hours.