Collagen supplements have gained popularity in recent years across a variety of industries including: sports, beauty and wellness. Collagen is also added as an ingredient to a number of food and drink products, like protein bars and matcha powders. This article will review the evidence behind the most common health claims regarding collagen supplements.
What is Collagen?
Collagen is a protein which is naturally produced in our body. It is also the most abundant protein in the human body – accounting for roughly 30% of our total protein content (1). Collagen is an important part of connective tissues – which provide support, structure and protection in our body, as well as binding together organs or other tissues (such as muscle tissue) (2).
There are 29 different types of collagen (3). The most common types of collagen are (2):
- Type I collagen: this is found in our skin, tendons, ligaments, bones and teeth.
- Type II collagen: this is found in our cartilage and the gel-like tissue in our eyes which is called the vitreous humour.
- Type III collagen: this is found in our skin, muscles and blood vessels.
Dietary sources of collagen include: meat (but not offal), poultry, fish, products containing gelatine (like jelly) and bone broth. It is difficult to digest and absorb collagen from our diet (4), therefore many supplements and food products contain hydrolysed collagen which is partially broken down in order to aid absorption.
However, consuming collagen in our diet doesn’t necessarily mean that this will become collagen in our body. This is because the protein is broken down and absorbed as amino acids, which become part of the ‘amino acid pool’ in our body. The body draws on this amino acid pool to create whichever proteins it needs most, which may not always be collagen. Similarly the body can create collagen using the amino acid pool – even if you don’t consume any dietary sources of collagen. Therefore, eating enough protein and including a range of essential amino acids in our diet is key. Essential amino acids are those which we must obtain through our diet, as the body can’t create these otherwise. Collagen doesn’t provide all of these essential amino acids in good amounts, as it is low in the amino acid tryptophan (4). This isn’t necessarily a problem, as long as we include sources of tryptophan in our diet, such as: fish, dairy, poultry, eggs, sesame seeds, soya beans and spirulina.
Skin Health 🤲🏼
Collagen is a vital component of our skin. In fact, collagen is thought to make up around 75% of our skin’s dry weight (5). Type I collagen is essential for skin elasticity and strength, and a loss of collagen in the skin, which occurs naturally with ageing, can lead to wrinkles (6).
There is some emerging evidence which suggests that taking hydrolysed collagen supplements may help to reduce wrinkles and improve collagen levels in the skin, as well as skin hydration and skin elasticity (5, 7, 8). However, there are issues with some of the studies in this area, for example some are very small, and don’t use a control group. Furthermore, more studies are needed in relation to the possible use of collagen supplements in skin conditions like eczema (5).
As discussed above, consuming oral collagen doesn’t necessarily translate to increased collagen levels in the skin, due to the breakdown and absorption of amino acids to our amino acid pool. Therefore, we can’t currently say that the use of collagen supplements is better than meeting our dietary requirements for protein.
The Advertising Standards Authority (ASA) in the UK has also criticised advertisements which suggest that consuming collagen contributes to youthful skin, due to the lack of evidence supporting oral consumption of collagen (9, 10). In 2013, the European Food Safety Authority (EFSA) also ruled that there is insufficient evidence for a cause and effect relationship between supplements containing hydrolysed collagen or collagen peptides and improvements in skin health (11).
Verdict: Although there is some evidence that collagen supplements have benefits for skin health, this is much weaker as compared with other lifestyle and skincare practices such as: daily sunscreen use, not smoking and consuming a balanced diet (12).
Hair & Nail Health 💅🏼 💇🏽♂️
There are a few ways in which collagen could theoretically boost nail or hair health. For example, collagen is a good source of the amino acid proline, which is one of the main amino acids used to create keratin – the main building block of our hair and nails. There is also some evidence that collagen which is derived from fish may act as an antioxidant in our body (13), which could potentially be beneficial for hair and nail health. However, there is little to no evidence in humans to support this.
One small study which included 40 participants found that taking a daily supplement which contained collagen, resulted in improvements in hair growth, volume and thickness (14). But we can’t say whether the improvements were specifically linked to collagen, as this supplement contained a variety of other ingredients, such as: antioxidants and botanicals.
Another small study found that taking a daily collagen peptide supplement for 6 months led to improvements in nail strength and growth (15). However, this only included 25 participants, and there was no placebo group – which reduces the strength of this evidence.
Verdict: There is very little convincing evidence that collagen supplements help with the health of our nails or hair. Consuming a balanced diet, which includes enough high-quality protein, vitamins, minerals and omega-3 fat is much more beneficial for nail and hair health in comparison with taking collagen supplements.
Joint Health 🤸🏽♀️
Collagen is a key component of the connective tissue and cartilage which is found in our joints. Some researchers have suggested that collagen supplements may help in the treatment and prevention of osteoarthritis (a loss of cartilage in joints) by reducing inflammation and preserving cartilage (16, 17, 18).
In 2011 the European Food Safety Authority (EFSA) reported there was insufficient evidence to claim that hydrolysed collagen aids in maintaining joint health in active individuals (19). Since then, a few small studies have found that consuming collagen may help in reducing joint pain related to exercise (20, 21, 22). There is also some evidence that collagen supplements can help with reducing pain related to osteoarthritis in the short term (23). However, these studies don’t provide evidence as to whether collagen supplements aid in athletic performance, or the recovery from joint injuries (24).
There is also some evidence that collagen supplements may help in the treatment of rheumatoid arthritis; which is an inflammatory form of arthritis that leads to swelling and pain in the joints (18). But this evidence is mixed, and there is much stronger evidence to support established medical treatments for rheumatoid arthritis, such as the medication methotrexate (18).
Vitamin C is vital for the collagen production (25). Therefore, supplementing with vitamin C may be beneficial for joint health in those who have a low intake of this vitamin. There is also some evidence which suggests that supplementing with 500mg of vitamin C per day for 50 days may decrease the risk of developing complex regional pain syndrome (CRPS) after a wrist fracture. CRPS is a chronic condition associated with joint injuries, which leads to painful and swollen joints, as well as changes in skin colour (26).
Similarly, one small study also found that taking a 15g vitamin C fortified gelatin supplement along with short bursts of activity increased levels of amino acids in the blood which are associated with collagen synthesis (27). It is worth highlighting that this is just one study, and it only included 8 participants. Other studies have found that vitamin C may help with healing tendon and ligament injuries, although more human studies are needed to investigate this (28).
Verdict: There is some evidence which supports the use of collagen supplements for reducing joint pain from exercise or osteoarthritis. In addition, supplementing with vitamin C may play a role in recovery from joint injuries.
Muscle Growth 💪🏾
Although certain types of collagen are found in our muscles, there isn’t much evidence as to whether supplementing with collagen improves muscle strength or growth.
A few randomised controlled trials have found that taking 15g collagen supplements after resistance training aids muscle growth, muscle strength and fat loss (29, 30, 31).
However, these studies compared the impact of resistance training plus a collagen supplement, with resistance training without any form of protein after training. As protein is key for muscle repair (32), these studies indicate that collagen is better than consuming no protein after resistance training. But there isn’t enough evidence to suggest that collagen is better than other forms of protein in terms of muscle growth and repair.
Verdict: A few studies have found that collagen supplements help with muscle repair after resistance training. However, this may be due to increased protein intake, rather than a specific benefit related to collagen.
Bone Health 🦴
Type I collagen is a vital component of our bones. A few lab-based studies have found that collagen peptides may boost the production of cells which stimulate bone production (these are called osteoblasts) (33, 34).
A small number of human studies have also found that taking collagen supplements may help to preserve and improve bone mass (34, 35, 36). However, similar to the studies related to muscle mass, we can’t rule out that the positive impact of collagen in these studies may be due to an increase in overall protein intake, rather than a specific benefit related to collagen.
Vitamin C has also been shown to aid bone healing, which may be related to the role this plays in synthesising collagen in our body (28).
Verdict: The overall evidence base related to collagen supplements and bone health is not robust. Check out this article for evidence-based dietary tips for improving bone health.
Weight Management ⚖️
A few small studies have found that consuming collagen, in the form of gelatin, may lead to a reduction in appetite (37, 38, 39). It is worth noting that each of these studies included less than 25 participants, and none measured actual changes in weight.
Verdict: It is unclear whether collagen supplements help to promote weight loss, as the research is currently very limited.
Gut Health 🧫
There is very little evidence to suggest that collagen supplements improve gut health.
One study found lower levels of collagen IV in the blood of individuals with inflammatory bowel disease as compared with healthy controls (40). Another study found that a fish-based collagen supplement helped to reduce the ‘leakiness’ (or permeability) of gut cells – however this was carried out in petri dishes rather than in living humans (41). Neither of these studies provide robust evidence to support the use of collagen supplements in order to improve gut health.
Verdict: There is much more evidence to support the gut-friendly impact of consuming a balanced diet which includes plenty of fibre and a wide variety of plants (42, 43).
Are There Any Side Effects to Collagen Supplements?
Some minor side effects have been linked with collagen supplements, such as: heartburn, diarrhoea, nausea and stomach pain (17, 44). Otherwise, collagen supplements tend to be safe. However this will depend on the specific supplement in question, as there can be issues with the regulation and testing of food supplements.
It is also important to note that collagen supplements are often derived from fish – therefore anyone who has a fish allergy should avoid this type of supplement. Vegan collagen supplements are available, which are made from genetically modified bacteria and yeast.
As the most abundant protein in the human body, collagen serves a number of important structural functions. Dietary collagen is more difficult for our body to absorb, as compared with hydrolysed versions.
The overall evidence-base associated with collagen supplements is limited. The strongest evidence is related to skin health and reductions in joint pain from exercise or osteoarthritis. However, this evidence remains far from robust.
Furthermore, consuming collagen orally does not necessarily translate to increased collagen levels in our body, as the amino acids from dietary collagen or collagen supplements are absorbed and used in the body as needed. Our body also creates collagen by itself by combining amino acids – so a varied diet which includes enough high quality protein is key. Good sources of protein include: meat, poultry, fish, eggs, soya – or a combination over the day of grains, beans and pulses.
(1) Di Lullo et al. (2002) “Mapping the ligand-binding sites and disease-associated mutations on the most abundant protein in the human, type I collagen.” [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/11704682]
(2) Molecular Cell Biology. 4th edition. Section 22.3 – Collagen: The Fibrous Proteins of the Matrix [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/books/NBK21582/]
(3) Parenteau-Bareil et al. (2010) “Collagen-Based Biomaterials for Tissue Engineering Applications” [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5445871/]
(4) Paul et al. (2019) “Significant Amounts of Functional Collagen Peptides Can Be Incorporated in the Diet While Maintaining Indispensable Amino Acid Balance” [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566836/]
(5) Choi et al. (2019) “Oral Collagen Supplementation: A Systematic Review of Dermatological Applications” [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/30681787]
(6) Calleja-Agius (2013) “Skin connective tissue and ageing.” [accessed March 2020 via:https://www.ncbi.nlm.nih.gov/pubmed/23850161?dopt=Abstract]
(7) Asserin et al. (2015) “The effect of oral collagen peptide supplementation on skin moisture and the dermal collagen network: evidence from an ex vivo model and randomized, placebo-controlled clinical trials.” [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/26362110]
(8) Proksch et al. (2014) “Oral intake of specific bioactive collagen peptides reduces skin wrinkles and increases dermal matrix synthesis.” [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/24401291
(9) ASA Website (2015) “ASA Ruling on Minerva Research Labs Ltd” [accessed March 2020 via: https://www.asa.org.uk/rulings/minerva-research-labs-ltd-a13-252489.html]
(10) ASA Website (2019) “ASA Ruling on HealthArena Ltd t/a Dermacoll” [accessed March 2020 via: https://www.asa.org.uk/rulings/healtharena-ltd-a18-446846.html]
(11) EFSA (2013) “Scientific Opinion on the substantiation of a health claim related to VeriSol®P and a change in skin elasticity leading to an improvement in skin function pursuant to Article 13(5) of Regulation (EC) No 1924/2006” [accessed March 2020 via: https://efsa.onlinelibrary.wiley.com/doi/abs/10.2903/j.efsa.2013.3257]
(12) Spiro & Lockyer (2018) “Nutraceuticals and skin appearance: Is there any evidence to support this growing trend?” [accessed March 2020 via: https://onlinelibrary.wiley.com/doi/full/10.1111/nbu.12304]
(13) Wang et al, (2013) “Isolation and Characterization of Collagen and Antioxidant Collagen Peptides from Scales of Croceine Croaker (Pseudosciaena crocea)” [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3853751/]
(14) Ablon & Kogan (2018) “A Six-Month, Randomized, Double-Blind, Placebo-Controlled Study Evaluating the Safety and Efficacy of a Nutraceutical Supplement for Promoting Hair Growth in Women With Self-Perceived Thinning Hair.” [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/29742189]
(15) Hexsel et al. (2017) “Oral supplementation with specific bioactive collagen peptides improves nail growth and reduces symptoms of brittle nails.” [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/28786550]
(16) Bello & Oesser (2006) “Collagen hydrolysate for the treatment of osteoarthritis and other joint disorders: a review of the literature.” [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/17076983]
(17) Moskowitz (2000) “Role of collagen hydrolysate in bone and joint disease.” [accessed March 2020 via:https://www.ncbi.nlm.nih.gov/pubmed/11071580]
(18) Woo et al. (2017) “Efficacy of Oral Collagen in Joint Pain – Osteoarthritis and Rheumatoid Arthritis” [accessed March 2020 via: https://www.researchgate.net/publication/316865631_Efficacy_of_Oral_Collagen_in_Joint_Pain_-_Osteoarthritis_and_Rheumatoid_Arthritis]
(19) EFSA (2011) “Scientific Opinion on the substantiation of a health claim related to collagen hydrolysate and maintenance of joints pursuant to Article 13 (5) of Regulation (EC) No 1924/2006” [accessed March 2020 via: https://www.efsa.europa.eu/de/efsajournal/pub/2291]
(20) Lugo et al. (2013) “Undenatured type II collagen (UC-II®) for joint support: a randomized, double-blind, placebo-controlled study in healthy volunteers.” [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/24153020]
(21) Czajka et al. (2018) “Daily oral supplementation with collagen peptides combined with vitamins and other bioactive compounds improves skin elasticity and has a beneficial effect on joint and general wellbeing.” [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/30122200]
(22) Zdzieblik et al. (2017) “Improvement of activity-related knee joint discomfort following supplementation of specific collagen peptides.” [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/28177710]
(23) Liu et al. (2018) “Dietary supplements for treating osteoarthritis: a systematic review and meta-analysis.” [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/29018060]
(24) Rawson ES, Miles MP, Larson-Meyer DE. Dietary supplements for health, adaptation, and recovery in athletes. [accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/29345167]
(25) Kishimoto et al. (2013) “Ascorbic acid enhances the expression of type 1 and type 4 collagen and SVCT2 in cultured human skin fibroblasts.” [Accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/23228664]
(26) Aim et al. (2017) “Efficacy of vitamin C in preventing complex regional pain syndrome after wrist fracture: A systematic review and meta-analysis.” [Accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/28274883]
(27) Shaw et al. (2016) “Vitamin C–enriched gelatin supplementation before intermittent activity augments collagen synthesis” [Accessed March 2020 via: https://academic.oup.com/ajcn/article/105/1/136/4569849]
(28) DePhillipo et al. (2018) “Efficacy of Vitamin C Supplementation on Collagen Synthesis and Oxidative Stress After Musculoskeletal Injuries: A Systematic Review.” [Accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/30386805]
(29) Hays et al. (2009) “Kajkenova O, Evans WJ. “Effects of whey and fortified collagen hydrolysate protein supplements on nitrogen balance and body composition in older women.” [Accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/19465192]
(30) Jendricke et al. (2019) “Specific Collagen Peptides in Combination with Resistance Training Improve Body Composition and Regional Muscle Strength in Premenopausal Women: A Randomized Controlled Trial.” [Accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/31010031]
(31) Oertzen-Hagemann et al. (2019) “Effects of 12 Weeks of Hypertrophy Resistance Exercise Training Combined with Collagen Peptide Supplementation on the Skeletal Muscle Proteome in Recreationally Active Men.” [Accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/31091754]
(32) Maughan et al. (2018) “IOC consensus statement: dietary supplements and the high-performance athletes.” [Accessed March 2020 via: https://bjsm.bmj.com/content/52/7/439]
(33) Hays et al. (2009) “Effects of whey and fortified collagen hydrolysate protein supplements on nitrogen balance and body composition in older women” [Accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/19465192]
(34) Fu & Zhao (2012) “In vitro responses of hFOB1.19 cells towards chum salmon (Oncorhynchus keta) skin gelatin hydrolysates in cell proliferation, cycle progression and apoptosis”
(35) Elam et al. (2015) “A calcium-collagen chelate dietary supplement attenuates bone loss in postmenopausal women with osteopenia: a randomized controlled trial. J Med Food. 2015;18:324-331.”
(36) König D, Oesser S, Scharla S, Zdzieblik D, Gollhofer A. Specific collagen peptides improve bone mineral density and bone markers in postmenopausal women: a randomized controlled study. Nutrients. 2018;10(1)
(37) Veldhorst et al. (2009) “A breakfast with alpha-lactalbumin, gelatin, or gelatin + TRP lowers energy intake at lunch compared with a breakfast with casein, soy, whey, or whey-GMP.” [Accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/19185957]
(38) Hochstenbach-Waelen et al. (2009) “Single-protein casein and gelatin diets affect energy expenditure similarly but substrate balance and appetite differently in adults
(39) Rubio et al. (2008) “Oral ingestion of a hydrolyzed gelatin meal in subjects with normal weight and in obese patients: Postprandial effect on circulating gut peptides, glucose and insulin” [Accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/18319637]
(40) Koutroubakis et al. (2003) “Serum laminin and collagen IV in inflammatory bowel disease” [Accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1770111/]
(41) CHen et al. (2017) “Collagen peptides ameliorate intestinal epithelial barrier dysfunction in immunostimulatory Caco-2 cell monolayers via enhancing tight junctions.” [Accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/28174772]
(42) MacDonald et al (2018) “American Gut: an open platform for citizen-science microbe research” [Accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/29795809]
(43) SACN (2015) “Carbohydrates and Health Report” [Accessed March 2020 via: https://www.gov.uk/government/publications/sacn-carbohydrates-and-health-report]
(44) Vijven et al. (2012) “Symptomatic and chondroprotective treatment with collagen derivatives in osteoarthritis: a systematic review.” [Accessed March 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/22521757]