Ilknur 2010.

Study characteristics
Methods	Aim of study: to compare the therapeutic effects of glycolic acid and amino fruit acids peels in participants with AV Design: single‐blind, randomised, right ‐ left comparison study Unit of allocation: split‐face Allocation: randomisation; drawing Blinding: single blinding; assessors Duration of trial (from recruitment to last follow‐up): not described Dropouts: 6
Participants	Population description: 0.25 to 2 grades AV Setting: not described Randomised number: 30 Age: 18.96 (13 to 30) years Sex: 7/17 (completed data) Severity of illness: grades of 0.25 to 2, Leeds technique
Interventions	Name of treatment group: glycolic acid n = 24 sides of faces Description: GA solution was applied (glycolic acid peels; Neostrata, Princeton, NJ, USA) at concentrations from the lowest to the highest (20%, 35%, 50%, 70%). It is a type of fruit acid. Treatment period: 6 months Timing: 2 to 6 minutes/peel; entire period is 6 months Name of treatment group: amino fruit acids gel group; n = 24 sides of faces Description: amino fruit acid gel was applied (amino fruit acid peels; exCel Cosmeceuticals, Bloomfield Hills, MI, USA) at concentrations from the lowest to the highest (20%, 30%, 40%, 50%, 60%) Treatment period: 6 months Timing: 2 to 6 minutes/peel; entire period is 6 months
Outcomes	Primary outcomes Participants' global self‐assessment of acne improvement (e.g. measured by a 4‐point scale: excellent, good, fair, and poor). Authors did not report this outcome. Withdrawal for any reason. Six dropouts during the 6‐month study. Split‐face design Secondary outcomes Change in lesion counts (total or inflamed and non‐inflamed separately). Reduction of non‐inflamed and inflamed lesion counts, baseline, week 4, 8, 12, 16, 20, and 24 Physicians' global evaluation of acne improvement. Authors did not report this outcome. Minor adverse events (assessed as total number of participants who experienced at least one minor adverse event). Mentioned minor adverse events and no summary statistics. Quality of life. Authors did not report this outcome.
Notes	Funding: not described
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "In order to determine which therapy would be performed on which side of the face, randomisation was conducted by drawing." Comment: drawing is reliable for random sequence generation
Allocation concealment (selection bias)	Unclear risk	No details of allocation concealment were described.
Blinding of participants and personnel (performance bias) All outcomes	High risk	This study is single‐blind which was applied to the outcome investigators and method to ensure blinding was not described. Blinding of participants probably insufficient
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "In the clinical assessment, each side of the face was evaluated by a doctor blinded to the study..." Comment: the method to ensure blinding of outcome assessor throughout the study was not described
Incomplete outcome data (attrition bias) All outcomes	High risk	6 dropouts (20%) with reasons; no ITT analysis was used. Number of missing data considered enough to introduce bias significantly
Selective reporting (reporting bias)	Low risk	Results reported for all prespecified outcomes in the methods section
Other bias	Low risk	No other potential bias identified