Collagen is the most abundant structural protein in the human body, an essential component of the extracellular matrix of skin, cartilage, tendons, bones, and blood vessels. With age, its endogenous synthesis progressively declines, and dietary supplementation represents one of the most studied nutritional strategies to compensate for this decline. Three studies published between 2025 and 2026—a narrative review on collagen and metabolic syndrome (Pueyo-Arias et al., 2025), a systematic review on regenerative applications (Ivaskiene et al., 2025), and a randomized, controlled clinical trial on native type II collagen and joint health (Möller et al., 2026)—provide an updated overview. The findings overall indicate biologically plausible and clinically relevant benefits, although, as always in science, further validation and larger studies are warranted.
What is collagen and why should you supplement with it?
Il collagen constitutes approximately 30% of the total proteins in the human body, playing a structural and functional role in the extracellular matrix of almost all connective tissues. At least twenty-eight types are known, but those of greatest clinical and nutritional relevance are type I (skin, tendons, bones), type II (articular cartilage), and type III (blood vessels, skin). Starting around age twenty-five, the synthesis endogenous collagen decreases with age gradually but progressively: a process associated with a reduction in skin elasticity, deterioration in joint function, and increased vulnerability of tendons to overload injuries.
– collagen supplements available on the market are mainly divided into two categories with distinct mechanisms of action:
the peptides of hydrolyzed collagen, obtained by enzymatic hydrolysis of the native protein, have a low molecular weight which facilitates intestinal absorption and systemic distribution as biochemical signals capable of stimulating the synthesis of endogenous collagen in fibroblasts and chondroblasts;
il native collagen Undenatured type II, on the other hand, retains its original three-dimensional structure and acts primarily through an oral immunological tolerance mechanism, modulating the inflammatory response in the joints. Distinguishing between these forms is essential to correctly interpret the results of individual studies (Ivaskiene et al., 2025).
Skin, tissue repair, and horizons of translational research
The systematic review by Ivaskiene et al. (2025), published in Frontiers in Nutrition and based on over sixty clinical studies updated to October 2025, documents the benefits of collagen supplementation on skin, joints and connective tissues. Available data indicate that hydrolyzed collagen peptides improve theskin elasticity, support the joint function and promote the post-exercise recovery, especially if co-administered with vitamin C, silica or resveratrol, which enhance their biological efficacy. Athletes and seniors show a more marked response than the general population, probably due to a basal deficit in the turnover and repair mechanisms of endogenous collagen.
On the translational research level, the study introduces a cutting-edge perspective: the convergence between nutritional supplementation, advanced biosensors and smart materials. Electrochemical and optical platforms – including molecularly imprinted polymer (MIP)-based sensors, surface plasmon resonance (SPR) systems, and fluorescent assays with collagen-binding peptides – enable real-time monitoring of key biomarkers such as CTX-I, matrix metalloproteinases (MMPs), and hydroxyproline. These tools open concrete avenues towards a precision medicine where the individual response to collagen supplementation can be monitored and modulated in a personalized way (Ivaskiene et al., 2025).
Healthier Joints: A Study on Native Type II Collagen
One of the most relevant contributions of recent literature concerns the potential of collagen in preventing or slowing joint decline before the onset of full-blown pathology. The study by Möller et al. (2026), randomized, double-blind, placebo-controlled, enrolled seventy-four healthy subjects who felt joint discomfort during physical activity – a condition considered an early sign of cartilage degeneration, prior to any diagnosis of osteoarthritis.
Participants were randomly assigned to treatment with undenatured native type II collagen (CN2) at a dose of 40 mg/day or placebo for 180 days. Both groups showed improvements in joint function as measured by the KOOS score at the end of the period, but the CN2 group achieved significant benefits ahead of the placebo for the subscores pain, symptoms and quality of life. In the subgroup with more marked joint discomfort at baseline (VAS > 40 mm), collagen induced a significant reduction of CTX-II levels – blood biomarker of cartilage degradation – while in the placebo group these levels increased: a finding that suggests a protective effect on the tissue itself, not merely symptomatic. Recovery time after a standardized exercise test was also significantly shorter in the treated group (Möller et al., 2026).
Collagen and metabolic syndrome: a multilevel approach to risk factors
The narrative review by Pueyo-Arias et al. (2025), published in Nutrition Research Reviews from the University of Navarra, addresses a topic of great relevance for public health: the role of collagen in metabolic syndrome (MetS), that is the cluster of alterations – abdominal obesity, hyperglycemia, arterial hypertension, reduction of HDL cholesterol and hypertriglyceridemia – which significantly increases the risk of 2 type diabetes e cardiovascular diseases.
The picture that emerges is one of biologically plausible action at multiple levels:
on the front of the body weight, collagen peptides would promote the feeling of satiety, the stimulation of GLP-1 secretion and the oxidation of fatty acids through the activation of PPAR-α and the AMPK signaling pathway;
on the front of the glycemia, collagen would improve insulin sensitivity, the expression of the GLUT-4 transporter and the inhibition of the DPP-IV enzyme – a target of a consolidated class of antidiabetic drugs – thus prolonging the activity of the incretin hormones GLP-1 and GIP and supporting the function of pancreatic β cells;
the effect on the blood pressure it is mainly attributed to the inhibition of the ACE enzyme, with reduction of angiotensin II and promotion of vasodilation mediated by bradykinin and nitric oxide;
on the profile of the blood lipids, collagen peptides show the ability to increase HDL cholesterol and reduce LDL and triglycerides through modulation of PPAR-γ and AMPK;
finally, a role for collagen in supporting the composition of the intestinal microbiota, with increased production of short-chain fatty acids and reduction of pro-inflammatory and oxidative mechanisms (Pueyo-Arias et al., 2025).
The review, however, emphasizes the need for larger and longer-term clinical trials to define optimal dosages and long-term effects.
What to consider when choosing a collagen supplement
In light of the available evidence, some practical considerations can guide those evaluating collagen supplementation. source and form of the supplement are crucial:
hydrolyzed collagen finds wider application in skin, tendons and metabolism;
Native type II collagen is more specific for joint health.
Dosage affects results: the study by Möller et al. (2026) obtained significant effects with 40 mg/day of CN2 in the joint context, while for metabolic benefits the literature generally uses doses of 10–15 g/day of hydrolyzed collagen.
La duration of integration It is an often underestimated factor: most of the positive effects emerge in studies of at least three to six months, and intervention periods that are too short risk not detecting real benefits even in the presence of a genuine biological action.
Co-administration with Vitamin C It is recommended by several researchers, as this micronutrient is essential for the endogenous synthesis of collagen as a cofactor of prolyl- and lysyl-hydroxylase.
As with any dietary supplement, it’s a good idea to consult your doctor or nutritionist about product quality, source traceability, and your individual health conditions.
Collagen in the circular economy: valorizing by-products
An aspect of fundamental importance, consistent with the vision of GIFT For a sustainable food system, it’s about the origin of the raw material. Collagen isn’t ‘produced’ scratch, but extracted through processes of upcycling from by-products of the meat and fishing industries (skins, bones, scales, cartilage).
This circular economy strategy allows us to:
reduce food waste, transforming protein fractions otherwise destined for disposal into ingredients with high added value for human health;
improve sustainability: the use of advanced extraction technologies (enzymatic or with green solvents) minimizes the environmental impact compared to the production of other protein sources;
ensure traceabilityThe safety and efficacy of dietary collagen depend strictly on the control of the livestock or fishery supply chain of origin.
Food supplementation thus becomes not only an act of self-care, but a part of a regenerative bioeconomy which optimizes existing natural resources.
Conclusions
The most recent research presents a picture of dietary collagen as a nutritional tool with solid biological bases and a favorable safety profile. The study by Möller et al. (2026) documents that native type II collagen improves joint function and reduces cartilage degradation markers in healthy subjects with exercise-induced discomfort. The review by Pueyo-Arias et al. (2025) outlines the plausible biological mechanisms through which collagen may act on components of the metabolic syndrome, from body weight to blood glucose, from blood pressure to blood lipids and microbiota. Ivaskiene et al. (2025) finally foresee a future where collagen supplementation fits into a framework of precision regenerative health, combining nutrition, biosensing, and personalized biological monitoring. Research continues, and the scientific basis for a conscious use of dietary collagen is solidifying.
Bibliography
Ivaskiene, T., Viskelis, J., Streimikyte, P., Savickaitė, M., Mobasheri, A., & Kaspute, G. (2025). Collagen supplementation and regenerative health: advances in biomarker detection and smart material integration. Frontiers in Nutrition, 12, 1716166. https://doi.org/10.3389/fnut.2025.1716166
Möller, I., Martínez, K., Terradillos-Guillén, A., Costa-Larrión, E., Martínez-Puig, D., & Velasco-Álvarez, J. (2026). Efficacy and tolerability of native (undenatured) type II collagen supplementation for joint health in healthy volunteers: a randomized double-blind placebo-controlled study. Nutrition Journal. Advance online publication. https://doi.org/10.1186/s12937-026-01302-0
Pueyo-Arias, M., López-Yoldi, M., Navas-Carretero, S., González-Navarro, C. J., Zulet, M. L. Á., & Milagro, F. I. (2025). Collagen supplementation in metabolic syndrome: a narrative review unraveling the biological mechanisms and effects. Nutrition Research Reviews, 39, e10. https://doi.org/10.1017/S0954422425100309
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE – GIFT – Food Times) and Égalité.