Collagen: What Is It and How Is It Used?

What is it?

Collagen is a structural protein found throughout the human body, making up approximately 30% of the total protein content. It is a key component of connective tissues such as skin, tendons, ligaments, cartilage, and bones. Collagen provides mechanical strength and structure, helping tissues withstand stretching and pressure. There are at least 28 types of collagen identified, with types I, II, and III being the most common in the body.

Collagen is the body's primary structural protein, essential for the integrity of connective tissues.

Collagen molecules are composed of three polypeptide chains wound together in a triple helix, a structure that gives collagen its unique strength and flexibility. The amino acid composition of collagen is distinct, being especially rich in glycine, proline, and hydroxyproline. These amino acids are less abundant in other dietary proteins, which is why collagen is sometimes considered separately from other protein sources.

Type I collagen is the most prevalent, found in skin, bones, and tendons. Type II is the main collagen in cartilage, while Type III is abundant in skin, muscles, and blood vessels. The distribution of these types varies by tissue, and their physical properties are adapted to the specific mechanical demands of each tissue.

As people age, the body's natural collagen production declines, which is a normal part of the ageing process. This reduction can be influenced by factors such as genetics, sun exposure, smoking, and dietary habits. The visible and structural effects of this decline have led to interest in dietary collagen supplements, which are derived from animal sources and processed into forms that can be consumed orally.

Collagen is not only present in humans but is also a major protein in the connective tissues of all animals, which is why animal tissues are the primary sources for supplemental collagen. The extraction and processing methods used to obtain collagen from animal tissues can affect the final product's properties and its suitability for various uses.

Authorised health claims

Currently, there are no authorised health claims for collagen in the European Union. This means that no specific benefits for skin, hair, nails, joints, or other tissues can be legally claimed for collagen supplements or fortified foods in the EU.

The European Food Safety Authority (EFSA) has evaluated submitted claims regarding collagen and found insufficient evidence to support any health benefits that would justify an authorised claim. This applies to all forms of collagen, regardless of source or processing method.

Any marketing of collagen supplements in the EU must comply with these regulations, and products cannot be promoted as having effects on health, appearance, or physical function unless specifically authorised. This regulatory environment is designed to protect consumers from misleading or unsubstantiated claims.

Key limitations

• No EU-authorised health claims for collagen supplements.
• Collagen supplements are not permitted to be marketed as treatments or preventatives for any disease or medical condition.
• Individual responses to collagen intake may vary, and effects are not guaranteed.
• Collagen from animal sources may not be suitable for vegetarians or vegans.

There are currently no EU-authorised health claims for collagen supplements.

It is important to note that the lack of authorised claims does not necessarily mean that collagen is ineffective, but rather that current evidence is insufficient or inconclusive according to regulatory standards. Consumers should be cautious of anecdotal reports or marketing that suggests otherwise.

Another limitation is that collagen supplements are derived from animal tissues, which may raise ethical, religious, or dietary concerns for some consumers. Additionally, the environmental impact of sourcing collagen from livestock or marine sources may be a consideration for those seeking sustainable supplement options.

Product quality and composition can also vary widely between brands and batches. There is no universal standard for collagen supplement potency or purity, and contamination with heavy metals or other unwanted substances is a potential risk if manufacturing standards are not rigorously maintained.

Forms and alternatives

Collagen supplements are available in several forms, each with unique characteristics. The source and processing method can affect the product's composition and suitability for different dietary preferences.

Form	Source	Common Types	Typical Use	Suitability
Hydrolysed collagen (collagen peptides)	Bovine, marine, porcine, chicken	I, II, III	Powders, capsules, tablets, drinks	Not suitable for vegetarians/vegans
Gelatin	Bovine, porcine	I, III	Cooking, desserts, capsules	Not suitable for vegetarians/vegans
Marine collagen	Fish (skin, scales)	I	Powders, drinks	Not suitable for vegetarians/vegans; may be preferred by pescatarians
Vegan "collagen boosters"	Plant-based ingredients	—	Powders, capsules	Suitable for vegetarians/vegans; do not contain collagen

Hydrolysed collagen, also known as collagen peptides, is produced by breaking down whole collagen into smaller fragments using enzymatic or chemical processes. This increases solubility and allows the powder to dissolve easily in liquids, making it popular for mixing into drinks or foods. Gelatin is a partially hydrolysed form of collagen that gels when cooled, and is commonly used in cooking or as a gelling agent in foods and supplements.

Marine collagen is extracted from fish skin or scales and is often marketed as a more sustainable or hypoallergenic alternative to bovine or porcine collagen, though it is still not suitable for vegetarians or vegans. The amino acid profile of marine collagen is similar to that of other animal sources, but it may be preferred by those who avoid mammalian products for religious or personal reasons.

Vegan "collagen boosters" do not contain collagen but may include nutrients such as vitamin C, zinc, copper, or specific amino acids that play a role in the body's natural collagen synthesis. These products are suitable for those who avoid animal products but do not provide collagen itself.

Some supplements combine collagen with other ingredients, such as hyaluronic acid, biotin, or herbal extracts, though the evidence for combined effects is not established and such combinations do not have authorised health claims in the EU.

Collagen is also present in certain traditional foods, such as bone broth, oxtail soup, and aspic, where long cooking of animal bones and connective tissues releases gelatin and collagen into the broth. The amount and bioavailability of collagen from these foods can vary depending on preparation methods.

How to choose

When selecting a collagen supplement, consider the following factors:

• Source: Bovine, marine, porcine, or chicken. Choose according to dietary preferences, religious considerations, and potential allergies. Some consumers may prefer marine collagen due to concerns about bovine spongiform encephalopathy (BSE) or other zoonotic diseases, though regulated products are tested for safety.
• Form: Hydrolysed collagen is generally more soluble and easier to mix into foods and drinks than gelatin. Gelatin may be preferred for culinary uses where gelling properties are desired.
• Type: Type I is most common in skin and bone, Type II in cartilage, Type III in skin and blood vessels. Some products specify the collagen type, which may be relevant for those seeking a particular source.
• Purity and additives: Check for added sugars, flavours, sweeteners, preservatives, or other ingredients if you have sensitivities or wish to avoid unnecessary additives. Unflavoured products may be more versatile for mixing into different foods and drinks.
• Certification: Look for products tested for contaminants such as heavy metals, pesticides, or pathogens. Third-party testing or certification (e. g. , ISO, GMP) may provide additional assurance of quality.

For those comparing products, consider the amount of collagen per serving, the presence of supporting nutrients (such as vitamin C), and whether the product fits your dietary restrictions. Some products are formulated to be allergen-free or are produced in facilities that avoid cross-contamination with common allergens.

Packaging and shelf life may also be relevant. Collagen powders should be stored in a cool, dry place and used within the expiry date to maintain quality. Some products are individually packaged for convenience, while others are sold in bulk containers.

Price per serving can vary significantly depending on source, processing, and branding. Higher price does not always guarantee higher quality, so consumers should review ingredient lists and certifications rather than relying solely on marketing.

Dosage and use

There is no EU-established recommended daily intake for collagen. Supplement manufacturers typically suggest daily servings ranging from 2. 5 to 15 grams of hydrolysed collagen peptides, depending on the product.

• Collagen powders can be mixed into water, smoothies, coffee, tea, yoghurt, or other beverages and foods. Some users prefer to add collagen to hot drinks, as hydrolysed collagen is heat-stable and dissolves readily.
• Capsules and tablets offer a convenient alternative for those who prefer not to mix powders or who want a pre-measured dose. The number of capsules required to reach a typical dose may be higher than with powders.

Collagen is also present in certain foods, such as bone broth and gelatin-based dishes, though the amount and bioavailability may differ from supplements. Cooking methods, temperature, and duration can influence how much collagen is extracted into food.

There is no established best time of day to take collagen, and it can be consumed with or without food according to personal preference. Some products recommend taking collagen together with vitamin C, as vitamin C is necessary for normal collagen synthesis in the body.

It is important to follow the manufacturer's instructions regarding dosage and preparation. Exceeding the recommended dose does not guarantee improved results and may increase the risk of side effects. Supplements should not be used as a substitute for a varied and balanced diet.

Safety, interactions and risk groups

Collagen supplements are generally considered safe for most healthy adults when used as directed. However, individuals with allergies to the source material (e. g. , fish, beef, pork, chicken) should avoid collagen derived from those animals. Allergic reactions, though rare, can occur in sensitive individuals.

There is limited data on the safety of collagen supplements during pregnancy, breastfeeding, or in children, so these groups should consult a healthcare professional before use. The safety of long-term collagen supplementation has not been established in these populations.

Those taking medication or with chronic health conditions should also seek medical advice prior to starting any supplement. Collagen supplements may interact with certain medications or medical conditions, though specific interactions are not well documented.

Possible side effects may include mild digestive discomfort, such as bloating, feelings of fullness, or a bad taste in the mouth. These effects are generally mild and temporary, but anyone experiencing severe or persistent symptoms should discontinue use and consult a healthcare professional.

Supplements should be sourced from reputable manufacturers who test for contaminants such as heavy metals, as animal-derived products can be at risk for contamination if not properly processed.

Collagen supplements are not suitable for individuals following a vegetarian or vegan diet, unless the product is a plant-based "collagen booster" that does not contain collagen itself.