A wearable biosensing platform for continuous monitoring of inflammatory and metabolic biomarkers for real‐time health tracking and personalized care

Wearable biosensors have the potential to revolutionize health monitoring, yet reliable, time‐resolved hormone and cytokine tracking remains elusive. This study introduces a dual‐framework approach to enable circadian and immune profiling through perspired sweat sensing. First, sweat–saliva thresholds were calibrated for cortisol, melatonin, interleukin‐6 and tumor necrosis factor‐alpha, achieving significant classification performance (Area Under the Curve >0.80) for physiologically relevant salivary benchmarks. Second, circadian rhythmicity of each biomarker was modeled using circaCompare, revealing distinct oscillatory patterns stratified by age, gender, and stress. Young adults exhibited robust melatonin–cortisol phase separation and rhythmic immune signals. Older participants showed dampened amplitudes, phase shifts, and inflammatory dominance. Notably, stress exposure induced earlier cortisol peaks (Δ ≈ 6.7 h), suppressed melatonin rhythms, and heightened immune amplitude variability—hallmarks of circadian misalignment. These findings establish sweat as a valid, real‐time medium for capturing endocrine and immune cycles, with analytical tools capable of uncovering early physiological strain. This work lays a foundation for personalized chronobiological monitoring and stress‐risk screening in naturalistic settings.