Collagen is the most abundant protein in the human body, found in the bones, muscles, skin, and tendons.

Collagen forms a scaffold that provides strength and structure within the body. It is an essential component of connective tissue and plays a crucial role in holding the body’s cells together. It also gives strength and elasticity to the skin.

Endogenous collagen is natural collagen that the body synthesizes. Exogenous collagen is synthetic. It comes from an outside source, such as supplements.

Endogenous collagen has a number of important functions. Breakdown and depletion are linked to various health problems, such as scurvy.

People use exogenous collagen for cosmetic purposes, such as improving skin elasticity. Doctors also use it in techniques for wound healing.

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Collagen is a molecule. It is a tough, insoluble, fibrous protein.

It plays a major role in many structures, such as:

  • skin
  • tendons
  • blood vessels
  • cartilage
  • bone
  • connective tissue, which anchors cells to each other

Collagen is a key component of the extracellular matrix, a network of molecules that holds together the body’s tissues.

Healthy collagen levels contribute to:

  • joint health
  • protection of the kidneys and other organs
  • skin elasticity
  • a healthy cardiovascular system

Collagen is plentiful in the human body. According to some older research, one-third of the protein in the human body and three-quarters of the dry weight of skin consist of collagen.

There are around 28 types of collagen, and they all have different structures. Most are formed of fibrils, which are long, thin structures that are strong and flexible.

In the skin, collagen provides strength and elasticity. As people get older, their collagen levels fall, and collagen fibers become thinner and weaker. Some experts believe this may contribute to skin aging. For this reason, many skin care products contain forms of collagen.

Some types of collagen are resorbable. This means they can be broken down, converted, and absorbed back into the body. It can also be formed into structures outside the body, with various medical uses.

Products that aim to boost collagen levels can originate from humans and other species.

Skin fillers

Fillers that combine collagen dermal fillers with hyaluronic acid may increase skin elasticity by boosting collagen production.

This can help enlarge tissues, filling gaps — such as wrinkles — in the skin.

People use them to:

  • reduce wrinkles
  • improve the contours of the skin
  • fill out depressions
  • improve the appearance of scars

Manufacturers source these products from humans and other species. One filler uses cells from salmon and other fish. People should check the origin of their product and test first for any allergic reactions.

Learn about other types of dermal fillers and how they compare with Botox.

Wound dressing

Collagen plays a key role in the natural process of wound healing.

Aspects that applications of collagen can help with include:

  • controlling bleeding
  • reducing inflammation
  • managing blood vessel health and function
  • boosting the strength of scar tissue
  • restoring skin elasticity
  • attracting cells that promote wound healing
  • providing a platform for new tissue growth

Collagen wound dressings contain collagen and other substances that aim to boost healing.

They can take the form of:

  • dressings, for example, of sponge or fleece
  • gels
  • powders

Guided tissue regeneration

Doctors sometimes use collagen to form scaffolds. These provide temporary support while the body produces new cells during the healing process.

Membranes, plugs, or pads containing collagen can help with:

  • bone regeneration
  • wound healing
  • managing extraction sockets after dental surgery
  • promoting blood clotting

Research from 2011 notes that, in oral surgery, collagen barriers can prevent fast-growing cells around the gum from migrating to a wound in a tooth. This preserves a space where tooth cells have the chance to regenerate.

Since these membranes are resorbable, a surgeon does not need to remove them surgically once healing is complete.

Treatment of osteoarthritis

Collagen is essential for healthy cartilage and bones.

Some people say that taking supplements containing collagen hydrolysate may boost collagen levels and help manage symptoms of osteoarthritis.

In 2018, scientists published the results of a trial involving 120 people, half of whom took oral supplements containing collagen and other substances for 90 days, while the others took a placebo. In those who took collagen, joint pain fell by 43%, and joint mobility improved by 39%.

Further studies are needed to confirm that oral collagen can improve joint health.

Find out if diet can help manage osteoarthritis.

Skin revitalization

Boosting collagen production or preventing its decline may help keep skin strong, elastic, and younger-looking.

Possible ways of doing this include:

  • surgical treatments, such as injecting fillers
  • applying creams and other products
  • oral supplements containing hydrolyzed bioactive collagen peptides, vitamins, and antioxidants
  • dietary choices that provide nutrients and antioxidants that prevent oxidative stress

Consuming hydrolyzed collagen and certain nutrients may help boost collagen production or prevent its loss, according to some researchers.

Creams, powders, and other topical cosmetics that contain collagen often claim to revitalize the skin by increasing collagen levels in the body. However, studies have not shown that the skin can absorb the necessary ingredients in a way that will make a significant difference.

Learn how to boost collagen levels to improve skin health.

Factors that may contribute to lead to collagen loss or low collagen levels include:

  • hormonal changes due to pregnancy, menopause, health conditions, and so on
  • oxidative stress, which results from metabolic processes and lifestyle choices, such as smoking and diet
  • the natural process of aging
  • too much sun exposure, as ultraviolet rays can cause collagen to break down in the skin
  • low levels of ascorbic acid, also known as vitamin C, which can lead to scurvy

Some genetic conditions can affect the production of collagen. Osteogenesis imperfecta can lead to weak bones. Ehlers-Danlos syndrome (EDS) can produce a range of symptoms, depending on which type of EDS the person has. Both conditions can be fatal in some cases.

Here are some strategies that may help prevent collagen loss:

  • Eat plenty of fruits and vegetables, as they contain vitamins and antioxidants.
  • Avoid smoking and processed foods, which increase the risk of oxidative stress.
  • Protect the skin from sun exposure.
  • Ask a dermatologist about supplements and other products.

Learn more about collagen supplements.

Here are some questions people often ask about collagen.

What does collagen do for the body?

Collagen is essential for the health of bones, skin, blood vessels, and all the body’s organs. Low collagen levels can lead to joint problems and a lack of elasticity in the skin.

Is collagen worth using?

Studies suggest that supplements can boost collagen production in the body. However, creams that claim to rejuvenate the skin are unlikely to have a significant impact, as the molecules cannot pass through the outer layer of skin in a way that makes a difference.

What are the side effects of collagen supplements?

Possible adverse effects include mild diarrhea, a heaviness in the abdomen, and a rash. There may be interactions with other drugs. However, research has not yet shown which ones.

Collagen is a protein that the body produces. It plays an essential role in the structure and function of skin, cartilage, bones, and connective tissue.

Medical uses of collagen include dressings to promote wound healing.

Many people use products that contain or boost the production of collagen in the body to improve their skin. Some of these may be effective. However, more research is needed.