COL1A1: Can This Gene Predict Regrowth From Collagen Support?

Article Summary

The COL1A1 gene, responsible for producing a key component of type 1 collagen, has been associated with hair growth and structure. Certain genetic variations in COL1A1 might affect the balance of collagen chains, potentially influencing hair loss and the response to treatments. However, the current evidence is limited, and while there is some indication that these variants could play a role in treatment outcomes, more research is needed before COL1A1 can be used to guide personalized hair loss therapies.

Full Article

COL1A1 is a gene within the collagen superfamily, a large network that comprises at least 44 genes and 28 proteins. The collagen proteins have a variety of roles, with perhaps their most crucial being to support the structure of tissues throughout the body. COL1A1 and COL1A2 produce the protein chains that combine to form type 1 collagen, the most abundant type of collagen in the body, which has also been linked to regulating hair growth. Moreover, some studies have suggested that genetic variation in COL1A1 may cause differential responses to hair loss treatment.

This article will explore how relevant COL1A1 is to hair treatment effectiveness and how to interpret your genetic results to make the correct treatment choice.

What Is COL1A1?

Collagen Type I Alpha 1 Chain, or COL1A1, is part of the collagen superfamily. There are 44 genes encoding the proteins that make up the 28 different types of collagen, with some collagen types consisting of more than one protein (α chain).^[1]Ricard-Blum, S. (2011). The collagen family. Cold Spring Harbor perspectives in biology, 3(1), a004978. Available at: https://doi.org/10.1101/cshperspect.a004978 Collagens have a variety of key roles throughout the body, foremost of which is the promotion of cell growth and supporting the structure and organization of tissues.^[2]Sun, H., Wang, Y., Wang, S., Xie, Y., Sun, K., Li, S., Cui, W. and Wang, K. (2023). The involvement of collagen family genes in tumor enlargement of gastric cancer. Scientific Reports, 13(1), 100. … Continue reading

Type 1 collagen (COL1) is the most abundant of all collagen types within the body, representing over a quarter of the total protein content in mammals. It consists of two α1 chains, produced by COL1A1, and one α2 chain, produced by Collagen Type I Alpha 2 Chain (COL1A2). The three α chains assemble into a single procollagen and undergo multiple rounds of modification, with several molecules eventually assembling into a longer collagen fibril and, finally, a type 1 collagen fiber (Figure 1).^[3]Kruger, T. E., Miller, A. H., & Wang, J. (2013). Collagen scaffolds in bone sialoprotein‐mediated bone regeneration. The Scientific World Journal, 2013(1), 812718. Available at: … Continue reading

Given its abundance within the body, it is hardly surprising that COL1 has been detected in the scalp. Specifically, the connective tissue sheath surrounding the hair follicle was found to be a major source of type 1 procollagen, expressing greater amounts than other parts of the follicle. Moreover, they showed that the expression of type 1 collagen changes throughout the hair cycle, collectively indicating that type 1 collagen may play a key role in the growth and structure of hair follicles.^[5]Oh, J.K., Kwon, O.S., Kim, M.H., Jo, S.J., Han, J.H., Kim, K.H., Eun, H.C. and Chung, J.H. (2012). Connective tissue sheath of hair follicle is a major source of dermal type I procollagen in human … Continue reading

These results support an earlier study that found that Col1 levels in mice also changed based on the stage of the hair cycle. They found that levels of Col1 were approximately two-fold higher in the dermis of the skin in the anagen (growing) phase than skin in the telogen (resting) phase. Furthermore, they found that Col1 molecules underwent more modifications during the anagen phase. This indicates that the remodeling of collagen is more active in anagen skin, which may support the growth and migration of hair follicles.^[6]Yamamoto, & Yamauchi. (1999). Characterization of dermal type I collagen of C3H mouse at different stages of the hair cycle. British Journal of Dermatology, 141(4), 667-675. Available at: … Continue reading

What is the Evidence for Targeting COL1A1 For Hair Loss?

Although only a few studies have investigated COL1 in relation to hair health, the evidence they have provided is robust and certainly suggests that COL1 may well be an important factor in regulating hair growth. Owing to this, it is feasible that genetic variation in COL1A1 could influence hair loss treatments.

Research into the rs1800012 polymorphism of Col1 revealed that people with the GT genotype had a higher ratio of COL1A1:COL1A2 gene expression and α1:α2 chains than the GG genotype. Generally existing in a 2:1 ratio, due to the structure of COL1, any increase in this ratio would lead to an imbalance between the two types of α chain.^[7]Mann, V., Hobson, E.E., Li, B., Stewart, T.L., Grant, S.F., Robins, S.P., Aspden, R.M. and Ralston, S.H. (2001). A COL1A1 Sp1 binding site polymorphism predisposes to osteoporotic fracture by … Continue reading

This could lead to instability of the collagen molecules, indicating that it may be useful for people who exhibit this genotype to take supplements that might support collagen synthesis, such as silicon, cysteine, or collagen.

Furthermore, in an analysis of over 26,000 people, it was found that the rs1800012 polymorphism is associated with AGA. Unfortunately, the study does not state which specific genotypes are associated with AGA, but this does suggest that the rs1800012 polymorphism and COL1A1 play a role in hair loss. ^[9]Francès, M. P., Vila-Vecilla, L., Russo, V., Caetano Polonini, H., & de Souza, G. T. (2024). Utilising SNP Association Analysis as a Prospective Approach for Personalising Androgenetic Alopecia … Continue reading

It has also been found that COL1A1 expression is upregulated in people with AGA. However, the upregulation of COL1A1 was not linked to the rs1800012 polymorphism. Moreover, the same study also showed that the expression of COL1A2 is upregulated in people with AGA, which may cause the α1:α2 chain ratio to remain unchanged.^[10]Michel, L., Reygagne, P., Benech, P., Jean‐Louis, F., Scalvino, S., Ly Ka So, S., Hamidou, Z., Bianovici, S., Pouch, J., Ducos, B. and Bonnet, M., 2017. Study of gene expression alteration in male … Continue reading

Together, although these studies do suggest that COL1A1 and the rs1800012 polymorphism may be involved in hair loss, they also indicate that the underlying mechanism is not understood. Further studies are required to understand how the expression of COL1A1 and COL1A2, the rs1800012 polymorphism, and the α1:α2 chain ratio link to hair loss and AGA.

What Do Your Genetic Results Mean?

Your Result	COL1A1 (rs1800012)
	Variant 1 – GG genotype	Variant 2 – GT genotype
What it means	Normal α1 chain synthesis	Increased α1 chain synthesis
The Implication	May not benefit from supplementation that supports collagen formation	May benefit from supplementation that supports collagen formation, such as adenosine or cysteine

What Relevance Does COL1A1 Have for Hair Loss Treatment?

We have also created a rubric that helps to determine the relevance of a specific gene to hair loss based on the quality of the evidence in the above studies.

On a scale of 1-5, how important are these genetic results? (1 is the lowest, 5 is the highest)

This score is a rating based on evidence quality.

• Does this gene have any potential relevance for hair loss? (1 point)

Yes, COL1A1 and COL1A2 have been found to be overexpressed in patients with androgenetic alopecia (score=1)

• Does the totality of evidence implicate COL1A1 as a causal agent for hair loss? (1 point)

No, there is no published evidence to suggest that COL1A1 polymorphisms can cause hair loss (score = 0)

• Does the totality of evidence implicate COL1A1 as a predictive factor for hair loss treatment responsiveness? (2 points)

No, there is no data to suggest that COL1A1 polymorphisms can be used as a predictor for hair loss treatment responsiveness (score = 0)

• Is this quality of evidence on (3) strong enough to influence treatment recommendations? (1 point)

Since COL1A1 fails question #3, it cannot be awarded points for question #4 (score = 0)

Total Score = 1

Final Thoughts

While there is some evidence to suggest that genetic variation in COL1A1 may influence your response to treatment with collagen supplements, there is not yet strong enough evidence to make definitive treatment recommendations based solely on genotype. Furthermore, it is evident that the association(s) between COL1A1, rs1800012, and hair loss are not yet understood. Larger and more robust studies are needed to confirm the true predictive value of genetic testing for COL1A1 variants to personalize hair loss treatments.