Is SHBG useful for weight loss?

SHBG (sex hormone-binding globulin) is a carrier protein for testosterone and estradiol. Low SHBG levels are associated with insulin resistance, metabolic syndrome, and obesity. Conversely, weight loss – especially through calorie restriction and exercise – can increase SHBG. However, SHBG is not a direct tool for weight loss. The evidence is largely observational; no randomized controlled trials demonstrate that deliberately raising SHBG alone causes weight loss. Direct-to-consumer tests that market SHBG as a 'key to weight loss' overstate its clinical utility. SHBG may serve as a biomarker of metabolic health, but it should not guide weight management decisions. Proven strategies like energy balance, macronutrient quality, and physical activity remain the foundation. Caveat: Single SHBG measurements are influenced by hormonal status, liver function, and medications. Their predictive value for individual weight loss outcomes is limited.