Sex hormone-binding globulin (SHBG) is a transport protein that binds testosterone and estradiol with high affinity, rendering the bound fraction biologically inactive. Only free testosterone and albumin-bound testosterone (loosely bound) can exert physiologic effects. SHBG levels determine how much total testosterone is bioavailable.
GearCheck connects glossary concepts to your actual bloodwork — showing exactly where your values sit and what they mean in the context of your protocol.
Analyze My Bloodwork →GearCheck provides blood marker analysis and harm reduction education. Information is for educational purposes only and does not constitute medical advice. Always consult a healthcare professional.