Collagen is a fibrous protein abundant in the human body, accounting for about 25% of the proteins found in the organism. This polysaccharide, notably present in the connective tissues of the skin, tendons, and hair, plays an important structural role and helps maintain their structure. Collagen is also included in the formulation of cosmetic products intended to be applied to the skin or hair. It primarily provides moisturizing benefits but also has interesting antioxidant properties to protect cells from oxidative stress. However, despite its hair benefits, collagen in topical application does not seem capable of stimulating hair growth.
When taken orally, this active ingredient could have an effect. Studies in vitro have shown that collagen could prolong the anagen phase, which corresponds to the growth phase of the hair follicle, by stimulating the expression of IGF-1, VEGF, krt27, Gprc5d, and Ki67, which are growth factors for hair fibers. Additionally, this molecule could counteract the activity of the growth inhibitor factor TGF-β1. Finally, collagen appears capable of upregulating the Wnt/β-catenin signaling pathway, which is involved in the activation and differentiation of epidermal stem cells. These various properties of collagen make it a good candidate for use as a dietary supplement or nutraceutical to prevent hair loss or promote hair regrowth, in cases of alopecia, for example.
Studies in vitro and clinical trials, conducted with different forms of collagen, have addressed the issue and seem to confirm the potential of this active ingredient to stimulate hair growth. It has been particularly observed that incubating human hair follicle cells for 4 hours with collagen peptides increases their proliferation rate by an average of 31%. As a reminder, hair follicles are the skin appendages where hair originates.
It is also interesting to mention the study conducted in 2023 by FIORUCCI and his team. This study demonstrated that collagen supplementation combined with an appropriate treatment could enhance the effects of the treatment in cases of androgenetic alopecia or telogen effluvium. 72 individuals suffering from one of these conditions participated in the study and were divided into 2 groups. The volunteers in the first group, totaling 44, received a standard medication along with a dietary supplement containing 300 mg of hydrolyzed marine collagen, amino acids, iron, and selenium, while those in the second group, totaling 28, received only the medication. The effectiveness of the treatments was evaluated after 3 months by both the participants and the researchers, and better results were observed in the individuals who received both the medication and the collagen.
According to this study, it appears that collagen may have a real effectiveness in stimulating hair growth. However, it is important to keep in mind that the dietary supplement did not contain only collagen: the effect on hair growth cannot therefore be attributed solely to this active ingredient. Additionally, the scientists note two limitations to their study: the two groups were slightly unbalanced and the trial was not conducted in a double-blind manner.
Collagen is a promising active ingredient for stimulating hair growth, but it still requires further study.