For skin, hair, and nails: Russian scientists reveal everything you need to know about collagen.

What is collagen and why is it necessary?

Collagen is a fibrous protein composed of 17 amino acids. It serves as the primary building material for connective tissue in the body, specifically in the skin, tendons, cartilage, ligaments, cornea, teeth, nails, and hair. Additionally, it forms a significant part of the fiber network within tissues.

“In fact, it is more accurate to refer to collagens, as there are at least 28 types. Chemically, they differ in composition, amino acid sequence, and the level and type of modifications of individual amino acids. In the body, molecules of collagens are constantly synthesized with the involvement of various enzymes, forming correct and quite complex supramolecular structures. They perform several important functions, including support and regulation,” explains Olga Krasnykh, Associate Professor at the Department of Chemical Technologies at PNIPU and Candidate of Chemical Sciences.

“The main function of collagen is to maintain the elasticity, density, and structural integrity of tissues. This fibrous protein improves skin condition, making it more elastic, hydrated, and youthful in appearance, as well as promoting rapid tissue regeneration after burns, abrasions, and scratches,” adds Yulia Rozhkova, cosmetic chemist, Associate Professor at the Department of Chemical Technologies at PNIPU and Candidate of Technical Sciences.

Thanks to collagen, the nail plate becomes even, smooth, without cracks and peeling, while hair grows thick and shiny. It also strengthens bone tissue, reducing the risk of fractures, bruises, and dislocations. The protein enhances heart function and forms the walls of arteries, which are responsible for blood transport to internal organs.

How does collagen production change with age?

Collagen is produced by fibroblasts in connective tissue throughout our lives; however, its volume naturally decreases with age. It is synthesized most actively until the age of 25, while the human body is still developing and tissues are growing.

“The processes of breaking down worn-out collagen fibers and forming new ones occur in parallel. In youth, the synthesis and breakdown of the protein are balanced, but as aging progresses, this balance is disrupted. Therefore, the older a person becomes, the slower the process of restoring natural tissues,” says Yulia Rozhkova.

It is important to note that factors such as smoking, alcohol consumption, poor nutrition (simple carbohydrates), mineral deficiencies, stress, UV exposure, and adverse environmental conditions can affect collagen synthesis.

Do women and men equally need collagen?

Indeed, there is a connection between collagen production and a person's gender. Due to the influence of sex hormones, particularly estrogens, women experience a more pronounced decrease in collagen synthesis than men.

“The reason is that sex hormones stimulate the formation of collagen fibers and inhibit their degradation, preventing oxidative stress. Consequently, from the age of 45, women begin to undergo hormonal changes, leading to estrogen deficiency. The peak decline in collagen production in women occurs during premenopause and several years after menopause,” explains Yulia Rozhkova.

From which animals is collagen derived?

The raw materials for collagen in dietary supplements come from the connective tissues of animals and fish. According to scientists, bovine collagen is produced from cow hides and contains collagen types I and III. The latter is particularly suitable for restoring the musculoskeletal system (bones, joints, tendons, ligaments, and muscles).

“Marine collagen is extracted from the skin, scales, and bones of fish. It is especially beneficial for the skin, hair, joints, bones, and blood vessels. It is worth noting that it has a smaller molecular mass compared to bovine collagen, making it easier to absorb. There are also plant-based dietary supplements derived from algae and wheat, but such substances are not collagen; they are merely plant proteins,” emphasizes Yulia Rozhkova, Associate Professor at the Department of Chemical Technologies at PNIPU.

How to maintain the required level of collagen in the body through nutrition?

Experts at PNIPU believe that with a balanced and varied diet, a healthy body can produce the necessary amount of collagen independently, thus making additional supplements unnecessary. Many foods, including bone broth, chicken, fish, cashews, pumpkin seeds, avocados, fruits, berries, bell peppers, garlic, and greens, contain vitamins, minerals, and both plant and animal-based proteins that stimulate the production of this natural substance.

What happens after a dietary supplement enters the body?

After taking the supplements, chemical and biological transformations (including those influenced by our microbiome) occur in the human gastrointestinal tract, and what is absorbed undergoes metabolism.

Collagen is a glycoprotein whose primary component is a protein polymer, with amino acids serving as monomers. Upon ingestion, hydrolysis of peptide bonds begins in the body, resulting in the breakdown of the protein into shorter chains—peptides—and further into individual amino acids.

The composition of collagen is characterized by the absence of a complete set of essential amino acids in necessary quantities, thus it does not hold significant nutritional value. However, if the diet is balanced and of high quality, individuals receive enough protein from food sources such as fish, poultry, and meat.

“Collagen will undergo transformation regardless of its source. Thus, the body must synthesize the protein, meaning that the resulting fragments must be reassembled into a protein molecule and organized correctly in space to perform its functions,” explains Olga Krasnykh, Associate Professor at the Department of Chemical Technologies at PNIPU.

Since collagen molecules are not absorbed (not bioavailable) unless broken down into smaller fragments (tri- and dipeptides, individual amino acids), dietary supplements based on collagen are subjected to enzymatic hydrolysis to improve absorption. Therefore, commercially successful products are often based on partially hydrolyzed collagen, meaning they are no longer pure collagen.

Who should avoid collagen?

“According to medical sources, the use of dietary supplements is not recommended even at a balanced dose for individuals with allergies to proteins, a heightened tendency for thrombosis, liver and kidney diseases, or a predisposition to hypercalcemia—elevated calcium levels in the blood plasma. Anyone with chronic conditions should consult a specialist before starting a course,” explains Olga Krasnykh.

Currently, there is no data on systematic and comprehensive clinical trials of collagen-based dietary supplements either in Russia or abroad. It is assumed that components of collagen that eventually enter the bloodstream will be delivered to the most problematic organs and tissues to address crucial bodily tasks. However, there is no way to monitor this externally, so one cannot draw definitive conclusions about the effectiveness of such supplements for addressing specific issues.

“Collagen is not listed among the mandatory and recommended supplements for pregnant women. It cannot be said that its intake is completely safe. It is, to some extent, an experiment on oneself and the fetus, which is not entirely reasonable during pregnancy. Even if a woman took supplements without negative effects before pregnancy. If there are concerns regarding skin condition, it is better to use external cosmetic products based on collagen, as this method of application will not allow it to be absorbed into the bloodstream,” warns the expert from PNIPU.

What can result from incorrect collagen dosages?

Both domestic and foreign scientific literature reports that supplements based on hydrolyzed collagen can be beneficial for improving skin condition as a component of joint disease therapy, particularly in osteoarthritis. However, achieving the desired effect often requires a relatively high dosage and/or prolonged use, which can negatively impact the functioning of the gastrointestinal tract, including the liver and kidneys.

“Excessive collagen production and accumulation of collagen fibers can lead to the growth of dense connective tissue in specific organs and deformities, ultimately resulting in impaired function. An imbalance between collagen synthesis and breakdown leading to its accumulation can result in collagenoses—diseases of connective tissue,” notes Olga Krasnykh, Associate Professor at the Department of Chemical Technologies at PNIPU.

Excessive collagen intake can lead to liver fibrosis and digestive issues such as diarrhea, constipation, heartburn, bloating, and reduced appetite. Another negative consequence is an excess of hydroxyproline, a primary amino acid that is excreted through the kidneys and can lead to the formation of kidney stones.

What should consumers pay attention to when purchasing dietary supplements?

Actual quality control of dietary supplements by consumers is challenging. It is difficult to assess how well the manufacturer maintains quality, but one can request a quality certificate from the seller and apply common sense.

“It is important to pay attention to the completeness of information provided by the company, specifically regarding the source of collagen, the region, and the specifics of animal husbandry (pasture-raised or factory-farmed). The manufacturer must specify the type of collagen, amino acid composition, all additional ingredients added to the product, and the presence of micro- and macroelements. Consumers should avoid artificial colorings and sweeteners, chemical preservatives, GMO products, soy, and other potential allergens,” explains Olga Krasnykh.

Concerns regarding quality may relate to animal health, microbiological control of the dietary supplement, and the presence of any foreign components (heavy metals, organic compounds, etc.), which