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 metabolically inactive isomer of T3; T4 is converted to either active T3 or inactive rT3 depending on physiologic state. Elevated rT3 with normal/low free T3 indicates the body is shunting T4 toward the inactive pathway — common during caloric restriction, intense training, chronic stress, illness, or low T3 syndrome. The free-T3-to-rT3 ratio is more informative than rT3 alone (ratio >20 typically considered healthy, <10 suggests poor T4 → T3 conversion). No direct peptide effects in common stacks. Tirzepatide / Semaglutide can modestly raise rT3 during aggressive weight loss (adaptive thermogenesis pattern). KEY CAVEATS: low calories, low carbs, and overtraining all elevate rT3 acutely — interpret in the context of recent diet + training load.
Have a recent Reverse T3 (rT3) 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.