Peer Review Report For: The Effect of Whitening Creams Usage on the Adrenal Gland [version 1; peer review: 1 approved]

Background This cross-sectional study assessed the impact of long-term use of skin-whitening products containing corticosteroids on the function of the adrenal glands. Objectives To assess the impact of extended use of corticosteroid-based whitening creams on serum cortisol levels and to examine the prevalence of adrenal suppression among habitual users. Methods This research, executed at the Hawija Technical Institute from January to April 2025, included 57 participants aged 20 to 40. Before enrolling, all participants gave their written consent. Individuals with chronic endocrine disorders or those receiving systemic corticosteroids were excluded. They were split into two groups: 38 regular (14 male and 24 female) users of skin-whitening creams (≥3 months) as the experimental group and 19 (7 male and 12 female) non-users as the control group. The Mindray CL-900i, a fully automated chemiluminescence immunoassay analyzer, was used to measure the levels of cortisol in the serum. Results In comparison to controls (7.85 ± 3.54 μg/dL; p = 0.0004), users had a significantly lower mean cortisol level (4.25 ± 2.23 μg/dL), with 42% of users exhibiting cortisol