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
Muscle-mass-independent kidney function marker — preferred over creatinine-based eGFR for users with extreme body composition (heavily muscled OR sarcopenic). Cystatin C-based eGFR is more accurate in these populations and identifies early CKD that creatinine-based formulas miss. Order alongside creatinine when the user is very muscular (otherwise creatinine reads high without disease) or very lean elderly (creatinine reads low and hides disease). No direct peptide effects documented in common stacks; cystatin C is a passive kidney readout. KEY CAVEAT: glucocorticoid use, thyroid disease, and high-cell-turnover states (cancer, autoimmune) can affect cystatin C independent of GFR — context matters.
Have a recent Cystatin C 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.
Sign-in required. The analysis is saved to your private history and audit-logged.