Beginner's guide to collagen

Guide to collagenCollagen is a structural protein made up of long chains of amino acids. It makes up between 25% to 35% of all your body’s protein and is used as connective tissue in many vital parts, including skin, bones, muscles and ligaments.     

Collagen is continuously produced in and around specialist cells, but once you reach the age of about 25, your body can’t keep up with the demand. After this time, we lose on average 1.5% of our collagen every year, resulting in the fibres breaking and losing elasticity. This can cause reduced bone density, slower post-exercise recovery, and dull, wrinkled skin.

In this collagen guide:
1. Dealing with collagen loss
2. Collagen types and sources
3. The benefits of collagen
4. Taking collagen supplements
5. Criteria for high-quality collagen
6. Types of collagen products

1. How to deal with collagen loss

Collagen is constantly being produced and broken down. As you age, the factors that influence collagen breakdown increase, resulting in gradual loss over time. These factors include:

Age - Collagen loss occurs naturally as we age. This is likely because your collagen-producing fibroblasts age and your cells receive less stimulation from biochemical pathways.

Collagen loss

UV light- UV rays from the sun damage DNA that is needed to produce collagen proteins. It also increases the production of oxidising free radicals. This can be harmful to collagen found in the skin.

Free radicals - These are molecules that can take electrons from other molecules causing substances to breakdown and decay. They’re produced naturally in the body, but when they’re present, they can break down collagen chains. Ageing fibroblasts may not be sufficient to repair all the damage.

Sugar – High sugar levels can cause collagen to harden and then break into fragments. It does this by creating crosslinks between protein strands, which reduces their elasticity and flexibility.

Stress – Studies have found that when your body is under stress, collagen production slows.  This is because your cells and body systems are concentrating on responding to the cause of the stress.

Consequently, the best ways to reduce collagen loss is to treat these factors. This could include:

  • Swapping regular skincare for products for those that contain sunscreen
  • Improving your diet
  • Eat more foods that are rich in antioxidants
  • Reduce your intake of sugary foods
  • Making lifestyle changes to reduce stress
  • Regular meditation

2. The types of collagen

We know of at least 28 different types of collagen, but some are more common than others. These six are the most abundant in the human body and are most likely to be found in supplements:

Woman light

Type I – This strong, stretchy, fibrous protein is the most abundant protein type and can be found throughout your body. Particularly in skin, ligaments and bones.

Type II – Essential for joints, this collagen makes up cartilage and keeps your essential connective tissues strong and healthy.

Type III – These proteins form reticular fibres which are made up of crossing strands to create a fine mesh. It’s usually found in areas that need elasticity including the surface of your skin, blood vessels and muscle tissue.

Type IV – This collagen forms a thin membrane of connective tissue called the basal lamina. It’s found in the cells surrounding organs, muscles and fat. They provide extra strength and cushioning for the other cells and tissues.

Type V – Most commonly found in cell membranes and hair, type V collagen also works with other collagens to help them form small fibres called fibrils.

Type X - Collagen type X is a short-chain protein that plays an essential role in the growth of new bone tissue.

Collagen sources

The collagen used in supplements comes from a range of different sources. Where your collagen comes from may influence the benefits it provides and how quickly it takes effect.

The three types are vegan, bovine collagen and marine collagen but which type is best?

Bovine collagen

Grass bovine collagen

Bovine collagen is sourced from the bones and other byproducts of cows. The raw materials are boiled to extract the collagen, which is then dried to form a powder. Products made with bovine collagen are likely to contain collagen types I and III.

Other animals can be used to produce collagen such as chicken and pigs, but cows are the most common source.

Marine collagen


Ocean marine collagen
Marine collagen is sourced from the skins, fins, scales and bones of fish. These parts are collected, dried and crushed, then treated with acids and enzymes to extract the long collagen proteins from the waste material. Most marine collagen supplements contain only type I collagen, but some may have a small amount of type II as well. Type I is the quickest to absorb into your bloodstream making marine collagen supplements the most bioavailable.


Vegan collagen

Yeast vegan collagen

Collagen is predominantly an animal product, so it’s hard to create vegan supplements. However, they do exist. Scientists have been able to find ways of producing high-quality collagen proteins using yeast and bacteria. These types of vegan collagen can be hard to find, but many companies make an alternative by creating collagen-boosting supplements from a blend of vitamins, minerals and plant-sourced amino acids.

How do our bodies produce collagen?

Collagen is built throughout our bodies, mainly in specialised cells called fibroblasts. However, sometimes it’s made in the spaces between them. When this happens, enzymes are involved that can assist the building of the new structures.

To make a new collagen protein, amino acids are treated as building blocks and placed in the correct sequence as written in your DNA. They’re set-in specific orders to produce the necessary shapes and structures. In most cases, the production of collagen happens close to where it’s needed, so it’s useful if lots of amino acids or peptides are present in the area.

Collagen producing food
Supplements that contain collagen peptides are one way to top up the materials used to build collagen, but more commonly, we get them from food. Foods rich in protein such as meat, beans, eggs, and dairy are an excellent source of amino acids that can be used in collagen production. The amino acids proline, lysine and glycine, are particularly useful and can be found in high levels in bone broth, fish, shellfish and egg whites.

Besides amino acids, other nutrients are also needed for normal collagen production. For example, the enzymes that build collagen into folded protein structures will only work when vitamin C is present. This means that citrus fruits, berries and other vitamin C rich foods are also a great way to stimulate collagen levels.

What are hydrolysed collagen peptides?

Collagen proteins of all types are made up of chains of amino acids arranged into different forms. Hydrolysed collagen has been treated to break it down into short sections of two or three amino acids known as peptides. When you consume these short collagen pieces, it’s easier for your body to use them to create, maintain and repair your own collagen.

3. Benefits of collagen

Because collagen is such an essential component of most parts of your body, the potential benefits of taking a supplement are extensive. However, the studies that have been conducted so far have highlighted some results of particular interest:

Collagen for skin


Types I and III are the most beneficial for your skin as they can promote elasticity and hydration. This is the most researched benefit of collagen and several studies reported that regular supplementation with collagen peptides resulted in fuller skin with fewer wrinkles and dryness.

A review conducted in 2019 and published in the Journal of Drugs in Dermatology looked at the results of 11 studies and concluded “preliminary results are promising for the short-term and long-term use of oral collagen supplements for wound healing and skin ageing. Oral collagen supplements also increase skin elasticity, hydration, and dermal collagen density.”

Collagen for hair


In 2012, a small study looked at the effect of oral collagen supplements on the hair of women with self-perceived thinning hair. It concluded that “the oral supplement assessed in this study safely and effectively promotes significant hair growth in women with temporary hair thinning.”

How collagen supplements may be able to support hair growth is not yet understood, but there are plenty of theories. Some suggest that the collagen peptides can be broken down into amino acids and used in the production of keratin which makes up about 95% of hair structure.

Others believe that collagen’s antioxidant properties protect hair from the damage caused by free radicals. Another argument is that collagen creates a healthy dermal skin layer in which hair follicles can thrive.

Collagen for nails


Brittle nails can break easily and be unpleasant to look at, but collagen could support their structure by providing a supply of amino acids and keeping the nail bed healthy. To measure these effects, scientists conducted a study with 25 people who took 2.5g of peptides daily for 24 weeks. 80% of the participants felt that the peptides improved their nails, 12% showed an increase in nail growth rate, and the frequency of broken nails fell by 42%.

Collagen for joints


Collagen, particularly type II, is essential for the healthy maintenance of the cartilage and tissues found in joints. Throughout several studies, collagen supplements have been found to reduce joint pain and, in some cases, improve movement following an injury or arthritis.

A study focusing on joint pain in people with osteoarthritis found that 2g of collagen daily produced a significant reduction in pain over 70 days. The collagen supplement used was described as “effective in managing OA-associated symptoms over the study period, thereby improving patient's activities of daily living.”

Collagen for bones


As we age our bones slowly lose density leaving us at risk of fracture and long-term health complaints. It’s likely that if excess type I collagen peptides are present the bone may be able to rebuild its structure and density. Of the few studies have that have been conducted so far, the results indicate that over a long period collagen supplements may lower the levels of proteins that promote bone loss, raise the density of bone minerals and improve bone health.

In 2018, a study looked at the effect of specific collagen peptides in bone density. The results showed “the intake of specific collagen peptides increased bone mineral density in postmenopausal women”. During the investigation, bone markers also indicated “increased bone formation and reduced bone degradation”.

Collagen for muscles


When taken alongside strength training, collagen has been found to significantly increase muscle mass compared to the training alone. Studies indicate that this is particularly effective for those who’ve lost muscle mass due to age or poor health.

 In 2015, scientists conducted a study with 27 older men and combined collagen supplementation with regular resistance training.  The results demonstrated that “compared with placebo, collagen peptide supplementation in combination with resistance training further improved body composition”.

4. Taking collagen supplements

Do collagen supplements work?

The aim of collagen supplements is to provide your body with an abundance of the raw materials it needs to make new collagen. If these parts are available, it should be more convenient for your cells to synthesise new collagen proteins, rejuvenate tired-looking skin and maintain healthy bones and muscles.

However, there are not yet enough extensive studies to say conclusively if this works, although early indications look very promising. The small-scale studies that have been conducted and the anecdotal evidence from customers and reviewers report several beneficial effects.

How long do collagen supplements take to work?

Man running

Despite still needing more evidence to be sure of the effects of collagen supplements, what is clear is that most of them take place over a more extended period. Some changes in skin health have been noticed after a month, but differences in bone density can take place across a year or two. Whatever results you’re looking for it’s worth sticking with your supplement routine to achieve them.

How much should I take?

Different amounts of collagen work best for different reasons. Between 2.5g and 15g is an appropriate daily amount for most people.

  • 5g to reduce fine lines and small wrinkles.
  • 5g to boost your bone density.
  • 10g to support your joints and to improve the elasticity of your skin.
  • 15g for improving your muscle mass, recovery and strength.

Are there any side effects?

Currently, very few side effects have been reported from collagen supplements. Some people have mentioned a bad taste in their mouth and others have reported bloating and heartburn. As with any supplement should you experience any side effects, stop taking it and contact your doctor.

If you suffer from shellfish or fish allergy, you should avoid marine collagen supplements. Also, it’s vital that if you have any allergies, you familiarise yourself with the ingredients before taking any collagen supplement. Different companies will add their own range of components so may include something that may cause an allergic reaction.

On the whole, collagen is considered to be a safe supplement with few known associated risks.

5. Is high-quality collagen important?

Not all collagen supplements are the same and paying to get a high-quality, effective supplement will likely produce better results and save you money in the long run. To ensure that you’re buying the best, here are some things to look out for:

Collagen Quality Logos

Hydrolysed collagen – Collagen that’s been hydrolysed to produce small peptides doesn’t need to be broken down as much as full protein chains before your body can use it. This means they’re more bioavailable and will take effect quicker.

Organic certification – Items that have been certified organic have been thoroughly inspected and meet a strict set of standards. This means that they’re less likely to be contaminated with artificial fertilisers or chemicals.

Grass-fed / wild-caught – animals or fish that have greater freedom or better food are likely to be in better health and offer improved nutritional value. Cattle or fish fed on pellet food and treated with hormones or antibiotics aren’t likely to produce the same quality of collagen.

Lab-tested – Companies that conduct comprehensive lab testing are able to prove exactly what their products contain. Without this, it’s hard to be sure that the supplement contains what it says on the label. Ideally, look for products that have been tested by a third-party lab and the results are available for customers to view. Although this is still rare for collagen, it’s becoming more common.

Additional natural ingredients – Although you may prefer to get a collagen-only supplement, those that provide additional ingredients, such as vitamin C can be more effective or provide a broader range of benefits.

Collagen Peptides

6. Types of collagen products

When collagen is produced, it’s made into a powder that can be used to create a range of different products. The most common are:


Capsules are best suited if you’re in a hurry or want to take collagen when you’re out and about. They contain a precisely measured amount of the active ingredient and can be quickly swallowed with a sip of water. Some come in a brittle shell, but others are encapsulated in a softgel. Many people choose capsules because they don’t leak or have a strong flavour.


Collagen powder

Powder is the most versatile way to take collagen because it can be added to your food and drink. Because it’s finely ground it’s also considered to be the quickest product to absorb in your gut.

The only downsides are that it takes a little longer to prepare and it may have a slightly odd savoury flavour. Most collagen powder, particularly marine-sourced, is quick to dissolve and may come with added flavouring. Some brands have ranges of hot drinks that are not just delicious but come with additional benefits alongside that of the collagen.


Collagen in liquid form requires no preparation and comes either in a bottle or in pre-measured sachets. These are a popular way to take collagen because they can be thrown in a bag and taken quickly whenever they’re needed.

They often include flavouring to make them more enjoyable and because they’re premixed, they’re unlikely to have any grainy residue. However, the convenience comes with a price as these are often more expensive than other product types.


Tablets offer many of the same benefits as capsules, but they’re not as popular. This is usually because tablets are notoriously hard to dissolve and don’t break open as quickly as capsules do. However, not all tablets are the same; and some manufacturers promise that their tablets will dissolve quickly and thoroughly.


Walk by sea

Although there is lots still to learn about collagen, the early indications are promising. Small-scale studies and anecdotal evidence show that collagen supplements have several useful effects on skin, nails, hair, joints, bones and muscles.

To get the best from collagen, look out for hydrolysed collagen peptides that have organic certifications, have been tested regularly and are sourced from grass-fed cows or wild-caught fish. You may also like to choose those that have additional vitamins and minerals included to enhance the effects or boost your body’s collagen production.

Last updated: 1 March 2021. Fact-checked.


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