Skin
The body's largest organ — barrier, repair, and aging.
Overview
Skin is the body's largest organ — a barrier against the environment, a regulator of temperature and fluid, and a visible marker of aging. Its health reflects both external exposures and internal factors.
Why it matters
Beyond appearance, skin protects against infection and injury, and skin cancer is among the most common and preventable cancers. The strongest evidence-based skin interventions are sun protection and retinoids.
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How this usually unfolds
- Understand the system
- Know the key biomarkers
- Learn the common conditions
- Apply evidence-based interventions
Major functions
- Barrier protection
- Temperature and fluid regulation
- Sensation
- Vitamin D synthesis
- Immune surveillance
Common conditions
Prevention
- Sun protection (the strongest lever)
- Skin-cancer surveillance
- Avoid tanning and smoking
Improvement strategies
- Topical retinoids (best-evidenced for photoaging)
- Sunscreen
- Treating the specific condition
Explore this system across BioSignal
Related Foundations
Related Signal Records
Related peptide families
Related lifestyle interventions
Related diagnostics
Frequently asked questions
What actually reduces skin aging?
Sun protection and topical retinoids have the strongest evidence. Many marketed peptides and creams are cosmetic-grade with weak support — BioSignal rates them honestly.
Do collagen supplements help skin?
Some small trials suggest modest hydration/elasticity effects, but the evidence is limited and often industry-funded. See the Collagen Signal Record.
Educational information — not medical advice
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