Collagen: Uses, Benefits, Dosage, and Side Effects (2025)

Collagen is a structural protein that makes up the majority of connective tissues in the body. It is constantly being built up and broken down in fibroblasts, cells specialized in synthesizing collagen, and other cells.

When taken as a supplement, it provides the body with collagen or collagen peptides, short chains of amino acids derived from collagen that are easily absorbed and are commonly used for skin health, strength and muscle gain, joint function, and muscle recovery.

Table of Contents

Outcome Summary

This tier list summarizes the primary outcomes of collagen supplementation and grades them from A (best) to E (worst), based on up-to-date scientific evidence.

A: Best in class for that particular outcome. Recommended for practically everyone.
B: Worth the money for most people and backed by scientific evidence to provide significant positive effects.
C: Might be worth trying, but the effects are small to modest, or the research is limited in size and scope.
D: Generally ineffective, although not harmful.
E: Negative or even harmful effects.

You can find references in the detailed research review of each outcome below.

Effect	Tier (A = best, E = worst)	Summary
Muscle Growth	C	Collagen peptides might improve muscle gains, but not as much as high-quality proteins like meat, eggs, soy, or whey.
Strength	C	Some studies show a small but significant increase in maximal strength with collagen peptide supplements.
Muscle Protein Synthesis	D	Collagen is low in essential amino acids and does not boost muscle protein synthesis in a meaningful way.
Athletic Performance	D	Collagen supplementation does not increase athletic performance or recovery significantly.
Joint Health	C	Research supports the idea that collagen supplements can improve joint health. However, the benefits are not huge, and the studies are often small and of low quality.
Skin Health	B	Collagen supplementation improves skin hydration and elasticity and has a small but positive effect on reducing wrinkles.
Bone Health and Osteoporosis	C	Although the studies are small and limited, collagen may increase bone mineral density and reduce bone loss in osteoporosis.
Weight Loss	D	There is no evidence that collagen helps with weight loss or offers benefits other protein sources don’t.
Gut Health	C	Limited research suggests collagen supplements may reduce bloating and act as a prebiotic for gut health support, but more research is needed to confirm these benefits.

What Is Collagen?

Collagen is a fibrous protein that provides structure and support to connective tissue throughout the body. As the most abundant protein in the body, accounting for about 30% of its total protein content, collagen provides strength, elasticity, and structure to skin, bones, tendons, ligaments, and cartilage.

Like all proteins, collagen consists of amino acids. However, collagen is unlike most other dietary proteins. It contains 19 amino acids, one of which is hydroxyproline, which is not present in other protein sources like meat or whey. In addition, it does not contain any of the amino acid cysteine, which is common in foods like meat and whole grains.

Collagen: Uses, Benefits, Dosage, and Side Effects (1)

Source: 1

There are 29 known types of collagen in the human body. They differ based on their amino acid composition and structural role in different tissues.2 3

Type I is by far the most common, comprising more than 90% of the collagen in the human body, and types I and III are the most abundant in muscle tissue.
Types I through III are often the basis of supplements because of their known roles in skin, joint, and connective tissue health.

Collagen is rich in proline, glycine, and arginine but low in leucine and other essential amino acids, often categorizing it as a low-quality protein for muscle protein synthesis and of low anabolic potential for muscle growth.

Collagen has a unique structure with three intertwined chains that form a triple helix structure, giving it the ability to resist pulling or stretching forces.

Collagen: Uses, Benefits, Dosage, and Side Effects (2)

Food Sources

Collagen is found in certain protein-rich foods, particularly in animal-based products.

Animal organs like the liver and kidney provide collagen.
Made by simmering animal bones, bone broth is rich in collagen.
Chicken, especially with the skin, is a good source of collagen.
A processed form of collagen, gelatin is often used in desserts and found in jellied foods.
Collagen is present in the skin and connective tissues of fish. Sardines are a good choice because you can eat them whole, including the bones and skin.
Red meat, especially tough cuts, has plenty of collagen.
While not containing collagen itself, egg whites are high in proline, an amino acid that is a building block for collagen.

Collagen is not found in plant-based foods. However, some plant foods, such as soy, beans, and leafy greens, can provide the necessary nutrients to support the body’s own collagen production.

Collagen Supplements

Collagen supplements are often taken for skin, hair, and nails. Over the last decade, dietary supplements with collagen have also become increasingly popular for body composition outcomes, including muscle gain.

They are often made from fish, poultry, pigs, or cows. Vegan collagen supplements focus on boosting the body’s own collagen production. It is currently unknown if they have identical effects, and results from studies using animal collagen (the majority) might not be generalizable to vegan collagen products. Recently, genetically engineered yeast has been used to produce vegan-friendly collagen, but these products are not yet widely available.

Physiological Roles of Collagen

Collagen’s primary role is to supply structural support all throughout the body. It provides the cohesion, elasticity, and regeneration of all our connective tissues, including skin, cartilage, bones, and blood vessels.

Here are the major functions of collagen:

Structural Support and Strength

Collagen is a major component of the dermis, the middle layer of the skin, giving it strength and elasticity.
Collagen forms a scaffold for mineral deposition in bones, giving them their tensile strength and flexibility.
Collagen fibers in tendons and ligaments provide the necessary toughness to connect muscles to bones and bones to each other.

Healthy Joints

Collagen helps maintain cartilage integrity by reducing friction and absorbing shock during movement.
Collagen acts as structural support for synovial membranes and contributes to the production of synovial fluid, which lubricates joints.

Blood Vessel Integrity

Collagen is a critical component of blood vessel walls, providing the structure and flexibility to maintain proper blood flow and pressure.
In the event of vascular injury, collagen participates in angiogenesis (forming new blood vessels) and clotting.

Muscle Mass and Function

Collagen fibers are interwoven within muscle tissue, helping it stay flexible and transmit the force created by muscle contractions to the tendons, ligaments, and bones, allowing movement.

Organ Protection

Collagen forms protective sheaths around organs like the kidneys and liver, helping them maintain their shape and protect them from injurious forces.
Collagen provides structural support to alveoli in the lungs and makes gas exchange more efficient.

Hair and Nail Strength

Hair and nails are primarily made of keratin, a strong, fibrous protein that forms the main structural component of hair, skin, and nails. Collagen helps maintain the infrastructure that holds these proteins together, contributing to healthy skin.

Digestive Health

Collagen supports the lining of the digestive tract, contributing to gut barrier integrity and nutrient absorption.
It may help repair the mucosal lining of the stomach and intestines and help heal ulcers.

Eye Health

Collagen fibers are a major component of the cornea and sclera, helping maintain the form and transparency of the cornea.
In the eye’s vitreous humor, collagen helps maintain the eye’s shape and optical properties.

Dental Health

Collagen is present in the gums and periodontal ligaments, supporting tooth stability and gum integrity.

Immune Function

Collagen maintains the integrity of our skin and mucous membranes, acting as a first line of defense against pathogens.
It influences the behavior of immune cells by affecting the extracellular matrix they navigate through.

Wound Healing

Collagen is essential for healing wounds by forming new connective tissue to replace damaged tissue.
It helps form granulation tissue and scar tissue, closing wounds effectively.

Aging Process

Decreased collagen production as we age leads to wrinkles and sagging skin.
Reduced collagen can contribute to osteoporosis, making bones more brittle.

Metabolic Functions

Collagen provides essential amino acids like glycine and proline, which are vital for many metabolic processes.
Some collagen-derived peptides may have antioxidant properties, protecting cells from oxidative stress.

Sources: 4 5 6 7 8 9 10 11 12

Does Collagen Increase Muscle Mass and Strength?

There is some evidence that collagen, even though it is considered a low-quality protein, can improve body composition (the proportion of fat-free mass and fat in the body) and strength.

Two studies examine how combining collagen peptide supplementation with strength training over 12 weeks affects fat-free mass (FFM) in recreationally active men.13 14

In both studies, collagen peptide supplementation resulted in greater fat-free mass and strength increases compared to the placebo. However, the gains in FFM were not solely due to muscle growth.

While the groups receiving collagen supplementation increased their FFM more than the placebo groups, there were no significant differences between the groups in terms of muscle hypertrophy. Instead, the extra increase in FFM in the collagen group was likely due to an increased growth of connective tissues (e.g., tendons and ligaments) rather than an increase in muscle tissue.

A recent systematic review and meta-analysis (2024) reviewed eight studies involving 418 participants, including older men with muscle weakness and pre-menopausal women.3

One study looking at older sarcopenic men found a significant increase in FFM (~5 kg) with collagen supplementation (15 g/day) when combined with a 12-week resistance training program. In contrast, the placebo group only gained ~3 kilograms during the same period.

Overall, the meta-analysis found that collagen supplements led to noticeable improvements in fat-free mass (including lean muscle), tendon structure, muscle architecture, and strength. Exercise recovery was also better in terms of reactive strength (how well muscles bounce back from fatigue).

The improvements in fat-free mass and recovery were supported by moderate evidence, but tendon changes and strength outcomes were supported by lower-quality evidence, meaning further research is needed to confirm these findings.

The researchers suggested that collagen peptides could be a useful supplement for athletes or active individuals looking to improve their body composition, muscle recovery, and injury prevention.

In short, collagen peptide supplementation has a positive (albeit small) effect on fat-free mass due to both muscle growth and connective tissue remodeling (increased collagen synthesis). That includes muscle mass gains, although those are not nearly as significant as reported with high-quality protein sources like whey.

Does Collagen Protein Increase Muscle Protein Synthesis?

Muscle protein synthesis (MPS) is the process by which the body incorporates amino acids into muscle proteins. It increases after strength training and protein ingestion, and elevated MPS rates mean more muscle gain in trained individuals.15

The proteins considered the best for boosting MPS are those high in essential amino acids, like meat, eggs, and whey protein.16 Collagen protein is relatively low in essential amino acids, including the branch-chained amino acids like leucine that act as triggers for MPS.

Several recent studies compare collagen protein to other sources, such as whey and pea protein, to see if it can boost MPS despite being low in the critical amino acids.17 18 19 20

Without exception, they find that while so-called high-quality proteins like whey effectively trigger and elevate muscle protein synthesis, with or without exercise, collagen protein does not. Instead, MPS rates remain unchanged after collagen protein ingestion.

In short, collagen protein does not increase muscle protein synthesis, and a complete protein like whey that has a better amino acid profile, including leucine, is more effective.

Does Collagen Improve Athletic Performance?

Several studies examine if collagen peptide supplementation can improve athletic performance.

A recent meta-analysis reviewed existing studies to see whether adding collagen peptides to the diet of healthy, active individuals would boost their musculoskeletal performance (how muscles, bones, tendons, and ligaments work together during exercise).21

It looked at 13 studies that measured how collagen peptides affected performance parameters like muscle strength, endurance, and recovery after exercise. In some studies, participants were given collagen supplements, and their performance was compared to that of a placebo group that did not receive collagen.

Most of the studies (9 out of 13) showed that collagen supplementation did not significantly increase muscle strength. For example, there was no noticeable impact on maximum voluntary isometric contraction or one repetition maximum (1RM) between collagen groups and placebo groups.
In a few specific cases, collagen supplementation seemed to have a slight positive effect on explosive movements like handgrip strength, jump height, or rate of force development during squats. However, these effects were inconsistent and only found across a few studies.
Overall, the studies found no significant evidence that collagen can improve muscle recovery after intense exercise. However, there were a few isolated cases where collagen showed minor benefits. For example, after exercises that cause a lot of muscle damage, like drop jumps, some improvements in recovery (measured by jump height) were noted within 24–48 hours after training.
When it came to endurance performance or aerobic capacity (like how far or how fast someone could run), collagen peptides did not make a noticeable difference.

In short, collagen peptide supplementation does not significantly increase athletic performance in healthy individuals, either in terms of muscle strength or recovery. Studies show that any performance improvements are marginal or statistically insignificant.

Does Collagen Improve Joint Health?

Collagen supplements contain amino acids and peptides that help build joint cartilage and may reduce inflammation and joint pain. Small-scale studies suggest that these supplements may help reduce joint pain and improve function in some people, both those with osteoarthritis and healthy people, including athletes, but their effectiveness remains uncertain.

Collagen might improve joint health through two main mechanisms, depending on its form: native collagen and hydrolyzed collagen.22

Hydrolyzed collagen is broken down into smaller peptides and amino acids, which are absorbed into the bloodstream. These accumulate in joint cartilage and stimulate the production of new cartilage.
Native collagen mainly works by preventing the immune system from attacking the collagen in joints.

Osteoarthritis

Meta-analyses support the use of collagen and collagen peptides in osteoarthritis.23 24 Collagen supplements significantly improve osteoarthritis symptoms by reducing joint stiffness and improving function and pain.

However, the results vary significantly from study to study (which are often of poor quality), with some showing large effects, others minor, and some showing no benefits at all. In addition, several studies reporting the greatest benefits are financed by manufacturers of gelatin and collagen foods and supplements. Indeed, other researchers have highlighted biases and limitations in the available studies that might reduce the reliability of theresults.25

In short, collagen supplements might help people with osteoarthritis, but most studies are small and of low quality, and more research is needed to confirm any benefits and further explore potential mechanisms.

Effect in Athletes

Several studies demonstrate that collagen supplementation helps alleviate joint discomfort in athletes experiencing activity-related joint pain, according to a systematic review and meta-analysis.26

Supplementation with collagen peptides can improve joint mobility and reduce the reliance on alternative therapies for pain management.
Collagen might improve knee extension and ankle stability in athletes. For example, in participants with chronic ankle instability, collagen supplementation decreased the occurrence of the ankle “giving way” during physical activities. It was also helpful in conditions like Achilles tendinopathy.
The combination of collagen supplementation and specific exercise rehabilitation programs after a joint injury resulted in improved recovery and the ability to return to strenuous activities, though not always to pre-injury levels. Collagen peptides seem to support the healing of joint injuries in part by promoting collagen synthesis in cartilage and tendons.

In short, collagen supplements are promising for preventing and recovering from joint pain and injury in athletes. However, the benefits are not huge, and most studies are funded by the supplement industry. Even the one meta-analysis on the topic was written by someone who has previously received research funding froma company that makes collagen-based products.

While promising evidence suggests that collagen supplements can support joint health, particularly in reducing pain, the evidence is not entirely conclusive, with limitations and possible bias in the available studies, and more research is needed.

Does Collagen Improve Skin Health?

Collagen is a major component of the dermis (the middle layer of the skin), and damage from UV radiation, pollution, and cigarette smoke can reduce skin elasticity and accelerate skin aging. Collagen supplementation might counteract this damage through collagen synthesis from within.

There are several proposed mechanisms for how collagen supplements help the skin:27

Collagen fragments can act as precursors that contribute to the synthesis of new collagen in the skin, although they do not directly participate in protein synthesis.
They stimulate the production of collagen and proteoglycans in the skin.
Collagen supplements activate immune cells that reduce inflammation and rejuvenate tissue by increasing skin turnover.

More than a dozen studies, a 2020 systematic review, and a 2023 meta-analysis demonstrate that collagen supplements improve skin moisture and elasticity and reduce wrinkles, dryness, and signs of skin aging.27 28 29 The studies used many different doses and treatment durations, but all showed improvements in skin health without adverse effects.

Different types of collagen and peptides may have specific effects on skin health. In particular, collagen peptides called PRO-HYP and HYP-GLY have been linked to increased collagen production for re-building skin structure and reducing signs of aging like wrinkles.

Fish-derived collagen might have extra beneficial effects on skin health, including wrinkle reduction, elasticity, hydration, and skin radiance. For example, a study using fish collagen reported a 35% reduction in wrinkles after 12 weeks. However, the 2023 meta-analysis found that all collagen supplements, regardless of the collagen source (fish or non-fish), reduced visible signs of aging like dryness and loss of skin firmness.

Some studies noted that the benefits of collagen continued even after people stopped taking the supplements.

In short, research supports collagen supplementation for improving skin health. It has a meaningful impact on improving skin hydration and elasticity and a smaller but still positive effect on reducing wrinkles. The effectiveness may vary based on the source of collagen and the peptides involved, but more research is needed to determine optimal sources and dosages.

Is Collagen Beneficial In Osteoporosis and Bone Health?

Osteoporosis is a condition where bones become weak and brittle from the loss of bone mass. Over time, they become more prone to fractures. Low levels of estrogen after menopause increases the risk of osteoporosis, but other factors like age, diet, and some medical condition can also accelerate bone loss.

Collagen makes up a significant portion of the body’s bone structure, providing a framework for bone minerals like calcium to build upon. As we age, collagen and minerals like calcium diminish, weakening the bones.

Supplementing with collagen hydrolysate might slow down this deterioration by increasing the activity of cells that build bone (osteoblasts) while reducing the activity of cells that break down bone (osteoclasts).

There are only a few studies looking at the effects of collagen supplementation on osteoporosis markers and symptoms, but those are generally positive and without adverse effects.30 31 32

Collagen supplementation has also been shown to improve bone mineral density (BMD) in people without osteoporosis.

One study showed a bone mineral density increase of up to 7% in postmenopausal women with age-related reduced BMD (but no osteoporosis) after taking collagen peptides for a year.33 In another study, collagen supplementation improved bone health at the hip region in elite road-race cyclists.34

In short, collagen supplementation could be a helpful addition to managing osteoporosis by preventing further bone loss, increasing bone stability and mineral density, and providing relief from the pain many people with osteoporosis experience. A few studies also show improvements in bone mineral density in people without osteoporosis. However, current research is limited in both study number and size.

Does Collagen Help with Weight Loss?

High-protein diets are considered effective for weight loss.35 Some animal studies have suggested that collagen peptides may help improve lipid metabolism and regulate appetite-related hormones, but human trials have not provided clear or consistent results.36 37 38

One study on overweight adults using fish collagen peptides showed some improvements in body fat after 12 weeks. However, it had few participants, and factors like exercise and diet, not the collagen, might have been the main contributing factors.
Another study found that collagen supplementation did not improve weight loss in women compared to whey protein, which was more effective for body composition.
Lastly, a 2023 study found that collagen peptides reduced body fat in older adults, but the study had several limitations. For example, the participants did not take the supplement as instructed, and the weight loss might simply have been the result of an increased protein intake in general.

In short, while eating more protein is generally beneficial for losing weight, and collagen can be a source of protein, there is no evidence that it offers any particular benefits for weight loss.

Does Collagen Improve Gut Health?

The intestinal microbiota—the community of microorganisms in the digestive tract—contributes to our health in many ways, including regulating the immune system and protecting against pathogens.39 Gut dysbiosis is an imbalance in the gut microbiome, where harmful bacteria outnumber beneficial ones. It can potentially lead to digestive and overall health issues.

Collagen supplements often claim to improve gut dysbiosis by supporting the integrity of the gut lining and reducing inflammation. However, these claims are mostly based on animal models.

One study found that a daily 20-gram collagen peptide supplement reduced bloating and digestive symptoms in women. However, the study was not randomized or blinded and lacked a control group.40

While meta-analyses suggest that collagen peptides can serve as prebiotics to improve gut health, the research is still ongoing, with little concrete evidence based on human studies.41

In short, research suggests that collagen peptides could be beneficial for promoting gut health, but more research is needed.

Safety of Collagen

Collagen supplements are well-tolerated by most people. It is declared safe by both the European Food Safety Authority and the US Food and Drug Administration.42

There are almost no reported side effects in studies. Rare adverse effects are mild and may include digestive issues, such as bloating or stomach discomfort, and resolve on their own.

Those with a known allergy to the source of collagen (e.g., fish or bovine products), should avoid those specific collagen supplements. Other than that, there are no known drug−nutrient interactions.

Collagen products should be checked that they are tested for purity and sourced from animals raised in clean environments. If using marine collagen, the product should be sourced from fish caught in clean, uncontaminated waters to avoid exposure to pollutants like mercury or other heavy metals.

Dosage

The recommended dosage of collagen supplementation varies depending on the form used and the intended purpose. These are the dosages and types used in the studies and reviews mentioned above.

One type of collagen might have different effects and levels of bioavailability and effectiveness in the body than another, meaning the outcomes seen in clinical trials may not apply universally when other forms, brands, or types of collagen are used.

Osteoarthritis : 5−10 g/day of collagen hydrolysate (CH) or 40−300 mg/day of undenatured collagen type II (UC-II).
Rheumatoid Arthritis: 20−100 µg/day of UC-II.
Osteoporosis: 5 g/day of CH or specific collagen peptides (SCPs), often in combination with vitamin D and calcium.
Tendinopathy: 5 g/day of CH in combination with strength training exercises.
Hypertension: 5 g/day of CH or 13 g/day of of CH or hydrolyzed marine collagen peptides (HMCPs).
Type 2 Diabetes: 13 g/day of HMCPs.
Wound Healing: 10−15 g/day of CH for pressure ulcers and 36 g/day of CH for burns.
Skin Aging: 500 µg−10 g/day of CH, with some studies focusing on marine-derived collagen and specific bioactive peptides.
Cellulite: 2.5 g/day of bioactive collagen peptides (BCPs).
Brittle Nails: 2.5 g/day of BCPs.
Post-exercise Recovery, Body Composition, and Strength: 15−30 g/day of collagen peptides (CPs).
Sarcopenia: 15 g/day of CPs in combination with resistance exercise.

There is little evidence that taking a collagen supplement at a certain time of the day makes any difference. However, if used for exercise and strength training purposes, taking it in conjunction with a training session might offer additional benefits.

Vitamin C is essential for collagen synthesis in the body. Taking collagen supplements alongside vitamin C-rich foods or supplements may enhance effectiveness.

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