What the science says


The surge in collagen's popularity has transcended the boundaries of beauty trends, anchoring itself within the lexicons of health and nutrition. But beyond the marketing, let’s dive into what science reveals about this critical protein.

As producers of Marine collagen supplements, we are deeply committed to enlightening our customers—who are on a quest for health and beauty enhancements—with the most comprehensive and up-to-date information. Our dedication to this mission is reflected in the meticulous curation of scientific evidence, which underpins the efficacy of our products. We take pride in maintaining an expansive home database that boasts over 500 scientific articles, ensuring that our customers are well-informed and confident in their journey towards wellness with our supplements.

This article aimed to present the empirical evidence, available so far on the efficacy of collagen and its peptides in skin health, supported by clinical findings and nutritional science.

The collagen and its function:

Collagen is the most important protein generated by the human body, forming the scaffolding for numerous tissues. Its primary structure is predominantly composed of glycine, making up 33%, with proline and hydroxyproline contributing another 22%. These amino acids intertwine to create a triple helix, comprised of three α-chains.

Each alpha chain, approximately made up of 1014 amino acids and has a molecular weight near 100 kDa, coils into a left-handed helix with a trio of amino acids per turn, shaping the secondary structure.

The chains are twisted around each other into a triple helix to form a rigid structure (tertiary structure). The super helix represents the basic collagen structure (quaternary structure). This molecular conformation has superior stability due to intramolecular hydrogen bonds bridging glycine residues across neighboring chains. The complete collagen molecule showcases a triple helical region flanked by two non-helical ends, each molecule weighing roughly 300 kDa, stretching 280 nm long, and about 1.4 nm in diameter.

Amongst the nearly 28 identified collagen types, type I is most prevalent, found in skin, bones, teeth, tendons, ligaments, vascular ligature, and various organs. Type II collagen predominates in cartilage. Type III collagen abounds in skin, muscles, and blood vessels. Type IV is discovered within the epithelial-secreted layer of the basement membrane and the basal lamina, while type V collagen is integral to cell surfaces and the placenta. The distinct nature of collagens is informed by their alpha-chain composition, the pattern, and length of the Gly-X-Y amino acid sequence, and the particular amino acids residing in the X and Y positions, typically proline and its hydroxylated companion, hydroxyproline.

Collagens are categorized into various families, including fibrillar and network-forming collagens; the FACITs, or fibril-associated collagens with interrupted triple helices; the MACITs, or membrane-associated collagens with interrupted triple helices; and MULTIPLEXINs, featuring multiple triple-helix domains and interruptions. Fibrillar collagen, as the predominant type in vertebrates, plays a crucial structural role, contributing to the molecular architecture, form, and mechanical traits of tissues. This includes providing tensile strength to the skin and resistance to traction in ligaments, a function served by collagens type I, II, III, V, XI, XXIV, and XXVII. (León-López A, 2019)

What are collagen peptides?

Peptides are short chains of amino acids linked by peptide bonds and are the building blocks of proteins. Typically, they are composed of 2 to 50 amino acids. They are smaller than proteins, which allows them to be more easily absorbed by the body. Peptides play various roles in the body, functioning as neurotransmitters, hormones, or growth factors, and they influence many physiological processes. For example, some peptides regulate hormonal activity, others have antimicrobial properties, or act as signaling molecules that can trigger or inhibit various biological pathways. They can also be synthesized artificially and used in medications, dietary supplements, and cosmetics for their various biological activities.

Bioactive peptides, comprised of 2 to 20 amino acid residues, are inactive within the sequences of their parent proteins and become activated through enzymatic hydrolysis. This activation can occur internally during the digestive process in the body, or externally during food processing methods such as cheese maturation and milk fermentation. Once released, these peptides can function as regulatory agents, exhibiting hormone-like effects within the body. Additionally, bioactive peptides can be produced via in vitro hydrolysis of proteins with specific proteolytic enzymes. The characteristics of the original protein, the particular enzymes employed for proteolysis, along with the hydrolysis conditions—like duration and temperature—and the proportion of enzyme to substrate, are all critical factors. These elements substantially dictate the molecular weight and amino acid profile of the bioactive peptides, consequently influencing their biological effects (Van der Ven et al., 2002).

Marine collagen peptides are sourced from the original collagen found in fish skins, which is then extracted and hydrolyzed into peptides through either a direct or a two-step process. In the direct hydrolysis process, fish skins are immediately hydrolyzed without an intermediate stage. The alternative method is more intricate, beginning with the extraction of fish gelatin, followed by a gentler and more precise hydrolysis to convert the collagen into peptides from the gelatin base.

Reaction time, enzyme type, temperature, and pH play vital role in what degree of hydrolysis will be obtained by the end of the process. The degree of hydrolysis measures the extent to which protein's peptide bonds are broken down into smaller peptides or amino acids, expressed as a percentage of cleaved bonds. This metric influences the hydrolyzed protein's properties, such as solubility, taste, nutritional value, and bioactivity. A higher degree of hydrolysis usually results in smaller peptides, enhancing solubility and digestibility but may introduce bitterness. Controlling the degree of hydrolysis is crucial for tailoring hydrolyzed proteins for specific uses, including dietary supplements and cosmetics.

A general principle is that a more controlled and extensive degree of hydrolysis typically results in a higher proportion of bioactive peptides in the final product.

Bioactive peptides working principles

The pivotal focus on low-molecular weight bioactive collagen peptides in discussions about collagen supplementation, especially prevalent in medical and cosmetological forums, addresses the critical question of whether these peptides can bypass the digestive system intact, without being degraded into individual amino acids.

Indeed, as mentioned earlier, the human digestive system breaks all consumed proteins into amino acids, each having its own critical function, which should not be underestimated. However, the topic we are addressing is whether bioactive peptides might have a direct impact on our own collagen synthesis production.

Bioactive peptides can exert their beneficial effects through 1) their uptake at the apical side of the polarized epithelial cell layer of the upper small intestine, or 2) by activation of different metabolic and sensory signaling pathways (Duca et al., 2021, Xu et al., 2019).

The first step is that the bioactive peptides consumed resist the digestion process and therefore must be resistant to gastrointestinal enzymes (Lu et al., 2021). Such as pepsin, and gastricin which are found in the stomach and are activated by hydrochloric acid, or to trypsin and chymotrypsin located in the small intestine and secreted in the duodenum (Sauer & Merchant, 2018).

When absorbed, they are subsequently transported through the epithelial cell monolayer into the blood vessels. For this, they use one or more of the following routes: carrier-mediated permeation, paracellular transport, transcytosis, and passive transcellular diffusion. (Xu et al., 2019).

The most recent research of bioactive collagen peptides suggests following mechanisms of impact on human body:

Mimicking Collagen Breakdown: When collagen breaks down, specific peptides are formed as natural byproducts. When we apply peptides (or skincare products containing them) topically, our skin believes it's a result of collagen breakdown. In response, the skin is tricked into producing more collagen to compensate for this perceived loss.

Sending Signals: Some peptides can send signals to skin cells, promoting the synthesis of collagen and other proteins. By sending this signal, these peptides can encourage the skin to produce more collagen. For instance, palmitoyl pentapeptide-4 (commercially known as Matrixyl) is one such peptide known to stimulate collagen production in the skin.

Stimulating Fibroblasts: Numerous studies suggest that the ingestion of collagen peptides can stimulate fibroblast cells' activity. Fibroblasts are the primary cells responsible for producing collagen in the skin. By stimulating these cells, there's an increase in collagen synthesis.

Hence, when comparing regular collagen powder to those containing a high proportion of bioactive collagen peptides, we can draw two main conclusions. The first is that the roughly hydrolyzed collagen powder is likely to be broken down into free amino acids by the digestive system. In contrast, powder containing bioactive peptides may exert a direct impact on the body’s own collagen production.

While empirical evidence and some studies suggest benefits to skin health from collagen supplementation, the detailed biochemical and physiological pathways are a topic of ongoing research.


Col Du Marine products are based on Naticol® range of bioactive and bioavailable marine collagen peptides of natural origin. Produced in France, Naticol® collagen peptides are created through a patented, gentle hydrolysis process that yields the market's highest proportion of low molecular weight bioactive peptides.

Much of the collagen research is funded by the manufacturers, who often include disclaimers indicating that 'specific peptides' may vary by source and manufacturing process. However, our emphasis is on the scientific evidence supporting Naticol® use, bolstered by extensive research from the industry leader covering a range of product applications, such as:

  1. Naticol® and collagen synthesis
  2. Skin beauty
  3. Joint health
  4. Sports nutrition
  5. Lean body mass and physical function
  6. Musculoskeletal condition
  7. Weight management
  8. Intestinal inflammation

We are pleased to present the original research papers on the aforementioned topics for our most demanding users below.

1. Naticol® and collagen synthesis (in-vitro)


2. Skin beauty – Clinical study CSR 3453 – 5.0 g per day intake
3. Skin beauty – Clinical study CSR 3453 – 10.0 g per day intake
4. Joint health – Clinical study AFCRO076 – Methods and results
5. Fish collagen peptides – A new key ingredient in sports nutrition
6. Lean body mass and physical function
7. Musculoskeletal condition
8. Effective weight management
9. Intestinal inflammation


While the effects of collagen are not yet officially recognized by medical authorities due to the absence of extensive clinical trials, the numerous reports of positive outcomes from thousands of users are compelling. Research into collagen peptides remains a highly active field, particularly in relation to anti-aging and health challenges posed by our modern environment. SIA Baltic Biotechnologies remains dedicated to the scientific exploration of the benefits of collagen and is committed to its mission of allowing everyone to personally discover the advantages of marine collagen.


León-López A, Morales-Peñaloza A, Martínez-Juárez VM, Vargas-Torres A, Zeugolis DI, Aguirre-Álvarez G. Hydrolyzed Collagen-Sources and Applications. Molecules. 2019 Nov 7;24(22):4031.

Van der Ven, C., Gruppen, H., de Bont, D. B. A., & Voragen, A. G. J. (2002). Optimization of the angiotensin converting enzyme inhibition by whey protein hydrolysates using response surface methodology. International Dairy Journal, 12, 813–820.

Xu, Q., Hong, H., Wu, J., & Yan, X. (2019). Bioavailability of bioactive peptides derived from food proteins across the intestinal epithelial membrane: A review. Trends in Food Science & Technology.

Sauer, J. M., & Merchant, H. A. (2018). Physiology of the Gastrointestinal System. In Comprehensive Toxicology: Third Edition (Third Edit, Vols. 3–15, Issue July 2017). Elsevier. 10.1016/B978-0-12-801238-3.99195-5.

Lu Y., Wang J., Soladoye O.P., Aluko R.E., Fu Y., Zhang Y. Preparation, receptors, bioactivity and bioavailability of γ-glutamyl peptides: A comprehensive review. Trends in Food Science and Technology. 2021;113(May):301–314. doi: 10.1016/j.tifs.2021.04.051.