hs-CRP is high-sensitivity C-reactive protein. It's a blood marker of chronic, low-grade inflammation, and it matters for skin because chronic inflammation is one of the most consistent drivers of collagen loss in the peer-reviewed literature.
CRP is a protein your liver makes in response to inflammatory signals. The high-sensitivity version of the test is calibrated to detect the small, sub-acute elevations that don't come from a fever or acute illness — they come from the low-grade inflammatory tone that many women carry silently.
That low-grade inflammation drives an enzyme family called matrix metalloproteinases (MMPs). MMPs are the enzymes that break down collagen and elastin. Fisher and colleagues at the University of Michigan established that MMP activation is a core mechanism by which both chronological aging and photoaging degrade skin structure (Fisher, 2002). Chronic hsCRP elevation is one of the most measurable upstream signals for that process.
The frame that has become common in the aging literature — inflammaging — describes exactly this pattern (Franceschi, 2000). Inflammation that doesn't hurt right now, that doesn't feel like anything, but that structurally ages tissue over years.
Clinically, hsCRP is normal below 3.0 mg/L. For skin longevity, the interesting range is well below that. Inflammation-lowering interventions with real evidence — omega-3 fatty acids, sleep, stress management, whole-food anti-inflammatory diets, resistance training — all move the number.
hs-CRP is one of the nine biomarkers on the JenSkin panel because it's one of the few numbers that lets you actually see whether the interventions you're doing are moving your inflammatory tone.