What Destroys Collagen, and How Do You Protect It?

Sunlight destroys more collagen than anything else you can control: ultraviolet light switches on the enzymes that cut collagen apart, and in a study of 298 women sun exposure was judged to account for about 80% of visible facial ageing. Behind it come smoking, sugar, heavy drinking and the menopause, on top of the slow decline that begins in the mid-twenties.^{1, 2, 3} Protecting collagen is mostly shade, sunscreen and not smoking. Vitamin C contributes to normal collagen formation for the normal function of skin, bones, cartilage, gums, teeth and blood vessels, and in a 2023 meta-analysis of 26 trials daily collagen peptides improved measured skin hydration and elasticity over eight to twelve weeks; a supplement sits alongside sun protection and does not replace it.^{14, 16} It is part of the Wellgard collagen guide.

How does the body make collagen, and why does it slow down?

Fibroblasts in the dermis build collagen from the amino acids in the protein you eat, mostly glycine and proline, using enzymes that need vitamin C. With age the balance between slow production and slow breakdown tips: the often-quoted figure of about 1% a year comes from a 1975 study of forearm skin that measured collagen falling steadily with age, and lower in women than in men at every age.¹

What is the biggest enemy of collagen?

Ultraviolet light. In 59 volunteers, a single dose of UV on buttock skin raised three collagen-digesting enzymes and increased the breakdown of type I collagen fibrils by 58%; with four exposures two days apart, collagenase activity stayed 4.4 times baseline for a week.² Across 298 white women aged 30 to 78, sun-seekers against sun-avoiders, the authors concluded that UV exposure seemed responsible for 80% of visible facial ageing signs, pigmentation and wrinkles above all; sagging tracked age in both groups.³

The NHS sun-safety advice is the collagen advice: "Spend time in the shade when the sun is strongest. In the UK, this is between 11am and 3pm from March to October." Use "a sun protection factor (SPF) of at least 30" with "at least 4-star UVA protection" and "do not rely on sunscreen alone": add "a wide-brimmed hat that shades the face, neck and ears" and "a long-sleeved top".⁴ Because "sunburn increases your risk of skin cancer", check your moles too: the NHS says see a GP about "a mole that's changed size, shape or colour", one "that's painful or itchy", or one "that's inflamed, bleeding or crusty".⁵ Peptides work from inside; sunscreen stops the damage. Both.

Does smoking destroy collagen?

Yes, measurably, even in skin the sun never reaches. In 47 smokers and 51 never-smokers, fluid drawn from the sun-protected inner arm showed type I and type III collagen synthesis 18% and 22% lower in the smokers, and twice the level of a collagen-degrading enzyme, MMP-8.⁶ Among 79 pairs of identical twins where one smoked, or smoked at least five years longer, that twin scored worse for sagging upper eyelids, lower-lid bags, nasolabial folds, lip wrinkles and jowls.⁷ Stopping is the largest protective step after the sun.

Does sugar damage collagen?

Through glycation, yes, though the evidence is chemistry rather than trials. Glucose and fructose bind to collagen and elastin and cross-link the fibres into advanced glycation end products, AGEs, which leaves them stiff and hard to repair; the process speeds up when blood sugar runs high and is stimulated further by ultraviolet light in skin.⁸ No trial has shown that cutting sugar changes the collagen in anyone's skin, so it is a reason to keep added sugar down, not a measured effect.

Does alcohol affect collagen?

Heavy drinking goes with faster facial ageing; no study has measured dermal collagen in drinkers. In a survey of 3,267 women aged 18 to 75 in four countries including the UK, who rated their own faces, eight or more drinks a week went with more upper facial lines, under-eye puffiness, mid-face volume loss and visible blood vessels, adjusted for age.⁹ An association, not proof.

Does the menopause lower collagen?

It does. Oestrogen supports collagen production, and in 69 untreated women thigh skin collagen fell significantly with the years since the menopause, while 37 women on hormone implants did not show the decline.¹⁰ Hormone replacement is a GP conversation; collagen and the menopause has the trials; the steps on this page matter more from the mid-forties, not less.

Does caffeine destroy collagen?

Not in any person studied. The claim traces to a 2014 study of skin fibroblasts grown in dishes with caffeine at 1, 2 and 5 millimoles per litre, concentrations no bloodstream contains, where collagen synthesis fell as the dose rose.¹² No study has found that coffee drinkers lose collagen, and in a 2025 randomised crossover trial collagen hydrolysate dissolved in coffee delivered its signature peptides to the blood with the same total uptake, peak and timing as in water.¹³ Heat does not harm peptides either (collagen in coffee). Whether a high habitual caffeine intake affects skin collagen in people is what we don't know.

Does collagen need vitamin C to work?

The enzymes that stabilise new collagen cannot work without vitamin C, which is why the Great Britain register authorises "vitamin C contributes to normal collagen formation for the normal function of skin", with matching claims for blood vessels, bones, cartilage, gums and teeth.¹⁴ The claim belongs to vitamin C; collagen itself has no authorised claim, a fact about the register rather than the trials. The NHS says adults need 40 mg a day and that more than 1,000 mg a day can cause stomach pain and diarrhoea.¹⁵ Vitamin C helps the body make collagen; it does not help collagen peptides absorb. What vitamin C is good for and what vitamins to take with collagen go further. Protein supplies the glycine and proline collagen is built from.

Can you rebuild collagen in your face?

Within limits, and only if you stop destroying it faster than you make it. In the 2023 meta-analysis of 26 randomised trials in 1,721 people, daily collagen peptides improved measured skin hydration and elasticity against placebo; the hydration effect varied with source and duration, and the elasticity effect did not differ by source.¹⁶ Those are instrument readings, not a count of new fibres; does collagen make you look better and which collagen is best for sagging skin set out what was measured. Retinoids are the other evidence: in the 1997 UV study, a prescription retinoid applied beforehand cut the enzyme surge by 70 to 80%.² Whether anything taken by mouth restores lost dermal collagen to its earlier level is what we don't know; no trial has biopsied for it.

What is the fastest way to increase collagen?

There is no fast way; collagen is made slowly and lost slowly, so protection comes first. Stop the losses: shade and SPF whenever the UV index reaches 3, no smoking, less added sugar, drinking within low-risk limits. Supply the inputs: protein at every meal and 40 mg of vitamin C a day. Then the trials used a daily serving for eight to twelve weeks before hydration and elasticity changed; what you can notice after taking collagen has the timeline. Anything promising a result in days is describing hydration, not collagen.

Frequently asked questions

What is collagen banking?

A clinic term for protecting and building collagen in your twenties and thirties, before loss shows. No study has tested it as a strategy; in practice it is this page applied early.

Do collagen-boosting foods work?

Only animal connective tissue contains collagen; fruit and vegetables supply the vitamin C that contributes to normal collagen formation. No trial shows a food raising collagen measured in skin. What foods are high in collagen gives the amounts.

Is elastin the same as collagen?

No. Collagen gives skin strength; elastin lets it spring back. Both are cross-linked by sugar and broken down by UV, and sagging tracked age rather than sun in the 298-woman study.^{3, 8}

Does sleep or stress affect collagen?

Possibly; nobody has measured collagen itself. In 60 women, poor sleepers (five hours or less) had higher intrinsic skin-ageing scores, and good sleepers recovered their skin barrier 30% more fully after tape-stripping: an association.¹¹ For stress there is no human skin-collagen study.

Sources

1. Shuster S, Black MM, McVitie E. The influence of age and sex on skin thickness, skin collagen and density. British Journal of Dermatology, 1975. PubMed 1220811.
2. Fisher GJ, et al. Pathophysiology of premature skin aging induced by ultraviolet light. New England Journal of Medicine, 1997. PubMed 9358139.
3. Flament F, et al. Effect of the sun on visible clinical signs of aging in Caucasian skin. Clinical, Cosmetic and Investigational Dermatology, 2013. PubMed 24101874.
4. NHS. Sunscreen and sun safety. nhs.uk.
5. NHS. Melanoma skin cancer: symptoms. nhs.uk.
6. Knuutinen A, et al. Smoking affects collagen synthesis and extracellular matrix turnover in human skin. British Journal of Dermatology, 2002. PubMed 11966688.
7. Okada HC, et al. Facial changes caused by smoking: a comparison between smoking and nonsmoking identical twins. Plastic and Reconstructive Surgery, 2013. PubMed 23924651.
8. Danby FW. Nutrition and aging skin: sugar and glycation. Clinics in Dermatology, 2010. PubMed 20620757.
9. Goodman GD, et al. Impact of smoking and alcohol use on facial aging in women: results of a large multinational, multiracial, cross-sectional survey. Journal of Clinical and Aesthetic Dermatology, 2019. PubMed 31531169.
10. Brincat M, et al. Decline in skin collagen content and metacarpal index after the menopause and its prevention with sex hormone replacement. British Journal of Obstetrics and Gynaecology, 1987. PubMed 3828252.
11. Oyetakin-White P, et al. Does poor sleep quality affect skin ageing? Clinical and Experimental Dermatology, 2015. PubMed 25266053.
12. Donejko M, et al. Influence of caffeine and hyaluronic acid on collagen biosynthesis in human skin fibroblasts. Drug Design, Development and Therapy, 2014. PubMed 25342885.
13. Virgilio N, et al. Unravelling the bioavailability of amino acids and bioactive peptides from collagen hydrolysate in coffee in healthy volunteers. Food Research International, 2025. PubMed 40356137.
14. Commission Regulation (EU) No 432/2012, Annex: permitted health claims (assimilated law in Great Britain). legislation.gov.uk.
15. NHS. Vitamin C. nhs.uk.
16. Pu SY, et al. Effects of oral collagen for skin anti-aging: a systematic review and meta-analysis. Nutrients, 2023. PubMed 37432180.

General information, not medical advice: a changing mole needs a GP appointment, and hormone replacement or stopping smoking is a conversation with your GP or pharmacist.