Rankings / Protocols — Light

Sunlight / circadian light exposure

Protocols · Light

Tier A-

serotoninvitamin
7.9 / 10
Tier A-
Ev 8.0 Bn 8.0 Sf 7.0 Ax 9.0

What this is

Morning light exposure is the single most potent circadian zeitgeber. Lindqvist et al.: sun exposure associated with reduced all-cause mortality comparable in magnitude to non-smoking. Balance UV risk with benefits.

Mechanism

Vitamin D synthesis via UVB; circadian entrainment via retinal ipRGCs (melanopsin); nitric oxide release from skin (BP lowering); mood via serotonin

Dose & route

5-30 min morning sunlight to eyes (no sunglasses) for circadian entrainment; 10-30 min midday skin exposure without sunscreen (adjust for skin tone)

This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.