Skin From The Inside Out
The skin routine with actual evidence behind it: daily sun protection and a retinoid do most of the work, everything else layers on top. Honest about what collagen powder can and cannot do.
Dermatology research is unusually clear on the hierarchy. Ultraviolet light drives most visible skin aging, so daily sun protection is the single biggest lever and it is nearly free. Topical retinoids have the strongest published evidence of any active for fine lines, texture and dermal thickness. Vitamin C, hyaluronic acid and a good moisturiser help. Oral collagen peptides show some benefit in trials but the evidence is mixed, the studies small and often industry-funded, so treat it as optional, not foundational. Diet, sleep and not smoking round it out.
Why it works▼
Wear broad-spectrum SPF daily
UV drives most visible aging; daily sunscreen prevents far more than any serum reverses.
Use a topical retinoid at night
Retinoids have the strongest trial evidence for wrinkles, texture and dermal thickness.
Add vitamin C serum and a moisturiser
Antioxidant support and hydration help, secondary to SPF and retinoids.
Do not smoke; limit deliberate sun
Smoking and UV are the two biggest accelerators of skin aging.
Sleep well and eat whole foods
Sleep and diet support repair and the skin barrier; omega-3 has modest skin support.
Try collagen peptides if you want
Some RCTs show benefit for elasticity and wrinkles, but the evidence is mixed and often industry-funded.
- Anyone starting a real skincare routine
- People overwhelmed by skincare marketing
- Those deciding if collagen is worth it
- Anyone serious about preventing skin aging
- Daily sun protection and not smoking outperform every serum and supplement combined; do those first
- Retinoids cause irritation and sun sensitivity; introduce slowly, use SPF, and avoid retinoids in pregnancy
- Oral collagen evidence is modest, mixed and often industry-funded; it is optional, and powders are not regulated like medicines
- New, changing or suspicious moles or lesions need a dermatologist, not a serum
- We may earn a commission on products bought through this page; sunscreen and not smoking are the free core
- Educational only, not medical advice
- July 3, 2026 Protocol published.
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Not medical advice. This page is for education only and is not a substitute for professional medical care. Consult a qualified clinician before changing your health routine.
Editorial disclosure. This protocol is written and fact-checked by the YourProtocol.ai editorial team directly from the primary sources cited below; it is not written or reviewed by any outside expert.