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
Essential trace mineral; component of glutathione peroxidase (key antioxidant enzyme) and required for thyroid hormone deiodination (T4 → T3 conversion). Selenium deficiency is one of the underappreciated drivers of suboptimal T4→T3 conversion — pair with rT3 and free T3 when investigating poor conversion patterns. Brazil nut soils variably high in selenium (one Brazil nut per day is often sufficient supplementation; more is not better, selenium has a narrow therapeutic window). No direct peptide effects in common stacks. KEY CAVEAT: high-dose selenium supplementation (>400 μg/day chronically) is associated with adverse outcomes — track to avoid over-supplementation as much as deficiency.
Have a recent Selenium 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.