In this guide15 sections
- Key Points
- What Is Collagen and What Does It Do?
- Why Does Your Skin Lose Collagen?
- What Happens When You Take a Collagen Supplement?
- Do Collagen Supplements Work? What the Research Shows
- Marine vs Bovine Collagen: Is One Better?
- Does Collagen Help Hair, Nails or Joints?
- Collagen Side Effects and Who Should Avoid It
- What Can Collagen Supplements Claim in the UK?
- Collagen and Vitamin C: What Actually Helps Your Skin Make Collagen?
- How to Protect and Boost Your Skin’s Collagen: Treatments With Better Evidence
- So, Are Collagen Supplements Worth It?
- Frequently Asked Questions
- References
- Talk to Us About Ageing Skin
Key Points
- Collagen is the main structural protein in skin. From your mid-twenties your skin makes less of it each year, and sun damage and smoking break it down faster.
- A collagen supplement does not travel to your skin intact. It is digested into amino acids and small peptides, and your body decides where they go.
- Pooled analyses of trials report small improvements in skin hydration and elasticity, but a 2025 meta-analysis of 23 trials found no effect in studies without industry funding or in the higher-quality trials.
- There are no authorised health claims for collagen in the UK, and the advertising regulator has upheld complaints against collagen ads that promised firmer skin and fewer wrinkles.
- Collagen supplements are generally well tolerated. The main downsides are cost, uncertain benefit and allergy to fish, beef or other sources.
- The steps with the strongest evidence for protecting skin collagen are daily sunscreen, not smoking, a prescription retinoid and, for visible ageing, clinic treatments that stimulate your own collagen.
Collagen supplements are big business in the UK, sold as powders, drinks, tablets and gummies with promises of firmer, plumper, younger-looking skin. This guide looks at what collagen actually does, what happens to a supplement once you swallow it, and what the clinical trials show when you look closely at who paid for them. It also covers the side effects, marine versus bovine collagen, and the treatments with better evidence if your real goal is to tighten sagging skin or soften lines.
If you are comparing options for ageing skin, our overview of skin tightening treatments explains what can be done in clinic.
What Is Collagen and What Does It Do?
Collagen is the most abundant protein in the body. In the skin, it forms a mesh of fibres in the dermis, the thick layer beneath the surface, which gives skin its strength and firmness. Elastin lets skin spring back, and hyaluronic acid holds water. Together they keep skin smooth and resilient.
Collagen is made by cells called fibroblasts, using amino acids from the protein you eat, especially glycine, proline and lysine, together with vitamin C, which the enzymes that build collagen depend on[1].
Why Does Your Skin Lose Collagen?
Collagen loss is a normal part of ageing, but how fast it happens depends a great deal on how you treat your skin.
- Age. Fibroblasts slow down with age. In a study comparing skin cells from people aged 18–29 with those from people over 80, the older cells produced around a third less type I procollagen, the building block of the main skin collagen[2].
- Sun damage. Ultraviolet (UV) light breaks collagen down and stops new collagen forming. In a study in the New England Journal of Medicine ↗, sun-damaged skin made 56% less new type I collagen than skin that had been protected from the sun[3]. Our guide to the signs of sun damage explains how this shows on the skin.
- Smoking. Smoking reduces blood supply to the skin and speeds up the breakdown of collagen, which is one reason smokers develop deeper lines, particularly around the mouth. Our article on smoking and cosmetic surgery covers its wider effects.
- Hormones. Skin collagen falls more quickly in the years after the menopause as oestrogen levels drop.
The visible result is thinner, less firm skin, fine lines that deepen into wrinkles and, in some areas, crepey skin. Other habits that speed this up are covered in our guide to lifestyle factors and facial ageing.
What Happens When You Take a Collagen Supplement?
Most collagen supplements contain hydrolysed collagen, also sold as collagen peptides: collagen from cow hide, pig skin or fish skin and scales that has been broken into small fragments so it dissolves easily.
Like any protein, it is digested in the stomach and gut into amino acids and short chains of two or three amino acids (peptides). Some of these short collagen peptides, such as prolyl-hydroxyproline, survive digestion and can be measured in the blood for a few hours afterwards[4]. Supplement makers argue that these peptides act as a signal that prompts fibroblasts to make more collagen, and laboratory and animal studies support that idea.
Two points are worth knowing, though:
- Your body decides where the building blocks go. There is no mechanism that sends swallowed collagen to your face. The amino acids join the same pool as those from any other protein you eat.
- Ordinary food does something similar. In one study, plain gelatin raised blood levels of the same collagen peptides as a hydrolysed collagen supplement[5], and eating cooked fish raised them too, by roughly a third as much as a supplement with the same amount of collagen[6].
Do Collagen Supplements Work? What the Research Shows
At first glance, the evidence looks encouraging. Several systematic reviews have pooled the randomised trials:
- A 2021 meta-analysis of 19 trials with 1,125 participants, 95% of them women, reported improvements in skin hydration, elasticity and wrinkles after around 90 days of hydrolysed collagen[7].
- A 2023 meta-analysis of 26 trials with 1,721 participants also found improved hydration and elasticity, but noted several biases in the trials and called for larger studies[8].
- A 2026 systematic review of 25 trials found improvements in most studies, but rated the majority of trials as having a high risk of bias[9].
A typical positive trial gave 69 women aged 35–55 either 2.5 g or 5 g of collagen peptides or a placebo every day for eight weeks. Skin elasticity improved in both collagen groups, but the changes in skin moisture were not statistically significant[10]. The improvements in these trials are measured with instruments; they are usually far smaller than the changes people hope to see in the mirror.
The trials that were not paid for by industry found no effect
Researchers have since asked a different question: does it matter who funded the trial? A 2025 meta-analysis in the American Journal of Medicine ↗ pooled 23 randomised trials with 1,474 participants[11]. Taken together, the trials showed improvements in hydration, elasticity and wrinkles. But when the authors split them by funding:
- trials funded by supplement or pharmaceutical companies showed significant benefits;
- trials without industry funding showed no effect on hydration, elasticity or wrinkles;
- the high-quality trials showed no significant effect on any measure, while only the low-quality trials showed an improvement in elasticity.
The authors concluded that there is currently no clinical evidence to support taking collagen supplements to prevent or treat skin ageing. Industry groups have challenged how some trials were classified, so this is not the final word, but it is a strong reason for caution. When a benefit disappears in the independent and better-designed studies, the simplest explanation is that the benefit is small or not there at all.
How long does collagen take to work?
Most trials lasted 8–12 weeks, which is where the “three months” advice on supplement packs comes from. If you decide to try one, judge it honestly at that point. If you cannot see a difference after three months, more of the same is unlikely to change that.
Marine vs Bovine Collagen: Is One Better?
Marine collagen comes from fish skin and scales; bovine collagen comes from cow hide. Marine collagen is often marketed as better absorbed, but there is no good evidence that it works better for skin. In the 2023 meta-analysis, the effect on elasticity did not differ significantly by collagen source[8]. Marine collagen is an option if you avoid beef or pork products for dietary or religious reasons, but it is not a reason to pay more.
The same goes for the format. Collagen powders, collagen drinks, liquid collagen, tablets and gummies all contain the same kind of digested protein, usually in much smaller amounts in tablets and gummies.
Does Collagen Help Hair, Nails or Joints?
Collagen supplements are often sold for hair, nails and joints as well as skin. The evidence for these is thinner still.
- Collagen for hair. There are no good-quality trials showing that collagen makes hair thicker or helps it grow. When the Advertising Standards Authority investigated one collagen drink ad, the company provided no evidence at all for its “thicker hair” claim. Hair thinning has many causes, from genetics to iron deficiency and thyroid problems, and is worth discussing with your GP rather than treating with a supplement.
- Collagen for nails. A few studies report fewer broken nails, but they were small and mostly had no placebo group, and “stronger nails” is not an authorised claim in the UK.
- Collagen for joints. Some trials in people with osteoarthritis report modest improvements in joint pain or function, but the results vary between studies and depend on how they were measured[9]. If joint pain is your main concern, your GP or a physiotherapist is a better starting point.
Types of collagen in supplements
Labels often list collagen “types”. Type I is the main collagen in skin, bone and tendon, and type III sits alongside it in the skin; type II is found in cartilage. Most hydrolysed collagen supplements are mainly type I, whatever the label says, as they are made from hide, skin or scales. Once digested, all types are broken down into similar amino acids and peptides, so the type matters less than the marketing suggests.
Collagen Side Effects and Who Should Avoid It
Collagen supplements are generally well tolerated, and serious side effects are rare in the trials[9]. The main collagen side effects and downsides are:
- Stomach upset, such as bloating, a feeling of fullness or heartburn.
- Allergy. Marine collagen can trigger reactions in people allergic to fish or shellfish, and some products contain egg. Check the source on the label.
- Dietary restrictions. Collagen is an animal product, so it is not suitable for vegans or vegetarians, and bovine or porcine collagen may not be suitable for some religious diets.
- Kidney disease. If you have been advised to limit protein, talk to your doctor before adding a protein supplement.
- Pregnancy and breastfeeding. There is little research, so check with your GP or pharmacist first.
- Quality. Supplements are sold as food, not medicines, so they are not tested for effectiveness, and the amount of collagen and other ingredients varies between brands.
- Cost. A daily supplement adds up over a year, for a benefit that may be small or absent.
There are no well-documented interactions between collagen and common medicines, but tell your doctor or pharmacist about any supplement you take, especially before surgery.
What Can Collagen Supplements Claim in the UK?
In the UK, a health claim on a food or supplement must be authorised on the Great Britain nutrition and health claims register. There are no authorised health claims for collagen itself, so collagen can be advertised as available but not as improving skin or joints (Radiocentre copy guidance ↗).
Brands often add vitamin C to their products, which allows them to use the authorised claim that vitamin C contributes to normal collagen formation for the normal function of the skin. That claim is about vitamin C, not the collagen in the tub.
The Advertising Standards Authority has upheld complaints against collagen supplement ads. In 2023, it ruled that a liquid collagen ad claiming to help skin elasticity and firmness, reduce fine lines and wrinkles and give thicker hair was misleading, because the evidence did not support the claims, and that claims about hydrated skin, stronger nails and joint health were unauthorised health claims (ASA ruling, November 2023 ↗).
Collagen and Vitamin C: What Actually Helps Your Skin Make Collagen?
Your body makes its own collagen, and it needs two things from your diet to do it: enough protein and enough vitamin C. Vitamin C is essential for the enzymes that stabilise new collagen fibres, and skin normally holds high levels of it[1].
For most people in the UK, a balanced diet already covers both. Good sources include:
- Protein: fish, chicken, eggs, dairy, beans, lentils, tofu and nuts.
- Vitamin C: peppers, citrus fruit, berries, kiwi, broccoli and tomatoes.
- Foods high in collagen: bone broth, fish with the skin on, chicken skin and gelatin. These are not essential, but they supply the same building blocks as a supplement.
How to Protect and Boost Your Skin’s Collagen: Treatments With Better Evidence
If your goal is firmer, smoother skin, these steps have stronger evidence than a supplement.
Daily sunscreen
Protecting the collagen you already have matters more than trying to replace it. In a 4.5-year randomised trial of 903 adults published in Annals of Internal Medicine ↗, people who used a broad-spectrum sunscreen every day showed no detectable increase in skin ageing, and 24% less ageing overall than people who used sunscreen only when they chose to[12]. In the same trial, a daily beta-carotene supplement, another “beauty from within” product, had no overall effect.
A prescription retinoid
Retinoid creams such as tretinoin are well studied for sun-damaged skin. In the same New England Journal of Medicine study, 10–12 months of 0.1% tretinoin cream increased new type I collagen formation by 80%, while a plain cream did not[3]. Tretinoin is a prescription medicine and can irritate the skin, so it should be started under medical advice and not used in pregnancy.
Clinic treatments that stimulate your own collagen
Several treatments work by causing controlled injury or stimulation in the dermis, which prompts your fibroblasts to make new collagen in the treated area:
- Laser treatments, such as Fotona 4D and laser resurfacing, for texture, fine lines and laxity. Our guide on whether Fotona 4D can tighten skin without surgery explains what to expect.
- Radiofrequency microneedling, such as Morpheus8, for skin firmness and texture.
- Injectable skin boosters, such as Profhilo, polynucleotides and other skin booster injections, for hydration and skin quality.
These treatments are not right for everyone, and the results depend on the starting point. Our guide to facial rejuvenation treatments compares the options by concern.
When is surgery the better option?
Collagen loss is only part of facial ageing. Over time the deeper tissues of the face and neck also descend, and the skin stretches. No supplement, cream or energy device can lift tissue that has dropped or remove skin that has stretched. If your main concern is jowls, deepening folds around the mouth or loose skin under the chin, surgery is usually the only option that makes a lasting difference:
- A facelift lifts and repositions the deeper tissues of the face and removes excess skin, treating jowls and laxity in the lower face.
- A mini facelift uses shorter incisions for earlier jowling and lower-face laxity, with a shorter recovery.
- A neck lift tightens loose neck skin and the muscle bands beneath it, and is often combined with a facelift.
Surgery changes the position of tissue, not the quality of the skin itself, so many people pair it with daily sunscreen, a retinoid and skin treatments to improve both.
So, Are Collagen Supplements Worth It?
For skin, the honest answer is: probably not. The trials that show benefits are mostly small, short and funded by the companies selling the products, and the independent and higher-quality trials show no clear effect. Collagen supplements are unlikely to do harm, so if you enjoy taking one and can afford it, there is no medical reason to stop. But it is not a substitute for sunscreen, and it will not reverse visible ageing.
If you want a noticeable change in skin firmness or lines, the money is better spent on sun protection, a retinoid and, if needed, an assessment for clinic treatment. As with cellulite creams, products that promise to change how your skin looks from the outside in, or the inside out, rarely match the claims on the label.
Frequently Asked Questions
Do collagen supplements actually work?
For skin ageing, the evidence is weak. Pooled trials report small improvements in hydration and elasticity, but a 2025 meta-analysis found that the benefit disappears in trials without industry funding and in higher-quality trials. There is currently no reliable evidence that collagen supplements prevent or reverse skin ageing.
What is the downside of taking collagen?
The main downsides are cost and uncertain benefit. Some people get bloating or heartburn, and marine collagen can cause reactions in people with fish allergy. Supplements are not regulated as medicines, so quality and dose vary between brands.
Do you need collagen if you eat enough protein?
No. Your body makes collagen from the amino acids in the protein you eat, together with vitamin C. If your diet includes enough protein and fruit and vegetables, you already have the building blocks your skin needs.
Does the NHS recommend collagen supplements?
No. Collagen supplements are sold as food supplements, not medicines, and they are not prescribed on the NHS to treat skin ageing.
Is marine collagen better than bovine collagen?
There is no good evidence that marine collagen works better for skin. In a 2023 meta-analysis, the effect on skin elasticity did not differ significantly by collagen source. Marine collagen suits people who avoid beef or pork, but should be avoided if you are allergic to fish.
How long does it take for collagen to work?
Most trials ran for 8–12 weeks. If you have not noticed a difference after three months, a supplement is unlikely to help.
Do collagen drinks work better than powders or tablets?
No. Collagen drinks, liquid collagen, powders, tablets and gummies all contain digested collagen protein. Drinks and powders usually contain more per serving than tablets or gummies, but there is no evidence that one format works better for skin.
Does collagen help with wrinkles on your face?
Not reliably. Some industry-funded trials report a small reduction in wrinkle depth, but independent trials have not confirmed it. Daily sunscreen, a prescription retinoid and clinic treatments such as laser or radiofrequency microneedling have better evidence for lines and wrinkles.
Does collagen make you look younger?
There is no reliable evidence that it does. Any changes reported in trials are small and measured with instruments rather than seen in the mirror, and they were not confirmed in independent studies. Protecting your skin from the sun has far stronger evidence for keeping skin looking younger.
Is it better to get collagen from food or supplements?
Your skin does not need collagen from either, as long as you eat enough protein and vitamin C. Collagen-rich foods such as bone broth, fish skin and gelatin supply the same building blocks as a supplement and raise the same peptides in the blood, usually for much less money.
References
- Pullar JM, Carr AC, Vissers MCM. The roles of vitamin C in skin health. Nutrients. 2017;9(8):866. doi:10.3390/nu9080866 ↗
- Varani J, Dame MK, Rittie L, et al. Decreased collagen production in chronologically aged skin: roles of age-dependent alteration in fibroblast function and defective mechanical stimulation. Am J Pathol. 2006;168(6):1861-1868. doi:10.2353/ajpath.2006.051302 ↗
- Griffiths CE, Russman AN, Majmudar G, et al. Restoration of collagen formation in photodamaged human skin by tretinoin (retinoic acid). N Engl J Med. 1993;329(8):530-535. doi:10.1056/NEJM199308193290803 ↗
- Yazaki M, Ito Y, Yamada M, et al. Oral ingestion of collagen hydrolysate leads to the transportation of highly concentrated Gly-Pro-Hyp and its hydrolyzed form of Pro-Hyp into the bloodstream and skin. J Agric Food Chem. 2017;65(11):2315-2322. doi:10.1021/acs.jafc.6b05679 ↗
- Iwasaki Y, Nakatogawa M, Shimizu A, Sato Y, Shigemura Y. Comparison of gelatin and low-molecular weight gelatin hydrolysate ingestion on hydroxyproline (Hyp), Pro-Hyp and Hyp-Gly concentrations in human blood. Food Chem. 2022;369:130869. doi:10.1016/j.foodchem.2021.130869 ↗
- Asai T, Takahashi A, Ito K, et al. Amount of collagen in the meat contained in Japanese daily dishes and the collagen peptide content in human blood after ingestion of cooked fish meat. J Agric Food Chem. 2019;67(10):2831-2838. doi:10.1021/acs.jafc.8b06896 ↗
- de Miranda RB, Weimer P, Rossi RC. Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysis. Int J Dermatol. 2021;60(12):1449-1461. doi:10.1111/ijd.15518 ↗
- Pu SY, Huang YL, Pu CM, et al. Effects of oral collagen for skin anti-aging: a systematic review and meta-analysis. Nutrients. 2023;15(9):2080. doi:10.3390/nu15092080 ↗
- Bassila C, Bassila JC, Slim M. Efficacy and safety of hydrolyzed collagen supplementation on skin health outcomes: a systematic literature review of randomized controlled trials. Eur J Clin Nutr. 2026;80(9):867-885. doi:10.1038/s41430-026-01778-3 ↗
- Proksch E, Segger D, Degwert J, et al. Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology: a double-blind, placebo-controlled study. Skin Pharmacol Physiol. 2014;27(1):47-55. doi:10.1159/000351376 ↗
- Myung SK, Park Y. Effects of collagen supplements on skin aging: a systematic review and meta-analysis of randomized controlled trials. Am J Med. 2025;138(9):1264-1277. doi:10.1016/j.amjmed.2025.04.034 ↗
- Hughes MCB, Williams GM, Baker P, Green AC. Sunscreen and prevention of skin aging: a randomized trial. Ann Intern Med. 2013;158(11):781-790. doi:10.7326/0003-4819-158-11-201306040-00002 ↗
Talk to Us About Ageing Skin
If you would like advice on firming your skin or softening lines, you can book a consultation at our Baker Street clinic by calling 020 7993 4849 or using the form below. We will look at what is causing the changes you have noticed and talk you through the options, from skin boosters and laser to facelift surgery, and a patient coordinator will be your point of contact throughout.
