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.
Wear broad-spectrum SPF daily SPF 30+ every morning, reapplied when outdoors; this is the highest-impact step by far
UV drives most visible aging; daily sunscreen prevents far more than any serum reverses.
Use a topical retinoid at night Start low (retinol 2 to 3 nights/week, build up); prescription tretinoin is stronger; expect weeks to months
Retinoids have the strongest trial evidence for wrinkles, texture and dermal thickness.
Add vitamin C serum and a moisturiser Vitamin C in the morning under SPF; a moisturiser/hyaluronic acid to keep the barrier healthy
Antioxidant support and hydration help, secondary to SPF and retinoids.
Do not smoke; limit deliberate sun No smoking/vaping; skip tanning; sunglasses and shade
Smoking and UV are the two biggest accelerators of skin aging.
Sleep well and eat whole foods Consistent sleep; a whole-food, lower-glycemic diet; omega-3 if you eat little fish
Sleep and diet support repair and the skin barrier; omega-3 has modest skin support.
Try collagen peptides if you want 5 to 10g/day if you choose; give it 8+ weeks; manage expectations
Some RCTs show benefit for elasticity and wrinkles, but the evidence is mixed and often industry-funded.
UV exposure accounts for the majority of extrinsic skin aging, which is why sun protection outperforms every serum and supplement over time.
View sources
Topical and systemic skin aging interventions: evidence, pitfalls and perspectives (review, 2026)
Human skin aging and the anti-aging properties of retinol (NIH/PMC review)
Dietary supplements for skin photoaging: systematic review & meta-analysis of 40 RCTs (Frontiers)
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 editorial team directly from the primary sources cited below; it is not written or reviewed by any outside expert.
Is this for you
- Anyone starting a real skincare routine
- People overwhelmed by skincare marketing
- Those deciding if collagen is worth it
- Anyone serious about preventing skin aging
Cautions
- 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
- Sunscreen and not smoking are the free core
- Educational only, not medical advice
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