Is SHBG useful for longevity?

SHBG (sex hormone-binding globulin) is a promising but not standalone longevity biomarker. It binds testosterone and estradiol, modulating their bioavailability, and is influenced by insulin, liver function, and inflammation. Observational studies link low SHBG to metabolic syndrome, type 2 diabetes, and increased all-cause mortality – yet the evidence is moderate and not causal. SHBG alone cannot predict individual lifespan; it is one piece in a complex hormonal and metabolic network. Consumer blood tests often include SHBG in hormone panels, but interpretation requires clinical context (age, sex, BMI, insulin resistance). Without medical guidance, a single SHBG value can mislead. In longevity research, SHBG is a useful marker but not a validated intervention target. Evidence: human-moderate. Sources: none in provided context.