What is the most important thing men over 40 should do for skin health — sunscreen or something else?

For men over 40, daily SPF 30+ broad-spectrum sunscreen applied to the face, neck, and dorsal hands is the single most evidence-supported intervention for preventing photoaging, actinic keratoses (pre-cancerous lesions), and squamous cell carcinoma, but the cardiovascular risk reduction from vitamin D synthesis via sun exposure must also be factored into total sun strategy, creating a nuanced balance rather than total avoidance (Diffey, Photochem Photobiol Sci, 2004).

Ultraviolet radiation (primarily UVA at 315–400 nm, which penetrates glass and causes dermal collagen breakdown) is the primary driver of dermal collagen loss beyond the 1%/year baseline rate. Men systematically under-apply sunscreen, average male facial application is 25% of the recommended 2 mg/cm², meaning most men's effective SPF is a fraction of the label. The daily SPF habit is the single most effective anti-aging intervention for skin that has evidence behind it. Retinoids (tretinoin prescription or over-the-counter retinol) are the second most evidence-supported topical for collagen preservation and are dramatically underused by men.

Honesty Scale: Solid (1) for SPF reducing photoaging and skin cancer. Solid (1) for tretinoin (topical retinoid) improving collagen density and reducing fine lines.

What to do: Daily SPF 30+ applied to face and neck, every morning, regardless of cloud cover or season. Add topical retinol (0.5–1%) at night 3× weekly if you want to actively preserve collagen. Tretinoin 0.025–0.05% by prescription is more effective than OTC retinol.

For the full picture, read The Skin Health Deep Dive