Evidence check: MC4R in the context of Haut

MC4R (melanocortin 4 receptor) is a key regulator of energy balance and is strongly associated with obesity. The variant rs17782313 (near MC4R) has been repeatedly linked to higher BMI and increased appetite in GWAS. In the context of skin, the evidence is much weaker: mechanistic studies suggest melanocortins may influence sebum production and inflammatory responses in sebaceous glands, but robust human data are lacking. Some studies propose a link between MC4R variants and acne, but effect sizes are small and findings inconsistent. Consumer DNA tests that market MC4R as a 'skin gene' typically overstate its clinical relevance. For skin health, factors such as UV exposure, skincare routines, diet, and other genes (e.g., FLG, MC1R) are far better supported. A standalone MC4R analysis does not provide meaningful skin risk assessment. Evidence grade: GWAS for obesity, mechanistic/unclear for skin. Sources: no specific PMIDs in the provided context.