Reference ranges
Optimal ranges are tighter than standard lab ranges and reflect functional-medicine targets, not the populations they were derived from. Reference bands depend on sex, age, and circumstance — Juno's lab analysis layers your profile context onto the printed range when you paste a value.
Peptide relevance
The biologically active fraction of testosterone — the part not bound to SHBG or albumin. Most clinically reliable when CALCULATED from total testosterone + SHBG + albumin (Vermeulen equation) rather than measured by direct immunoassay (the latter is notoriously inaccurate). Equilibrium dialysis is the gold standard but rarely ordered. Symptoms of low T correlate better with free T than total T, especially when SHBG is at the extremes. Same peptide interactions as total testosterone — exogenous androgens (TRT, AAS) raise it; CJC-1295 + Ipamorelin don't directly affect HPG axis but improving body composition can modestly lift free T via lower SHBG. RANGES SHOWN ARE FOR ADULT MEN; women typically <2 pg/mL.
Peptides that influence this marker
Documented to affect this marker. Click through for the full evidence-tiered profile.
- KisspeptinKISS1R agonist (hypothalamic neuropeptide)
Stimulates endogenous T via LH/FSH pathway
- SemaglutideGLP-1 receptor agonist
Fat loss can raise free T in obese men via reduced SHBG / aromatization
- TirzepatideGLP-1 / GIP dual agonist
Fat loss can raise free T in obese men via reduced SHBG / aromatization
Have a recent Free testosterone (calculated) value?
Paste it on the lab analysis page. Juno reads your active stack + (if shared) your medications and conditions, and surfaces plausible contributors with citations. Doesn't diagnose.
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