Talk:Collagen

Plagiarism in associated disorders section

The entire section is just copied from this article, which i dont think is the right way to add information to wikipedia. This needs to be fixed. SandHanitizr (talk) 11:24, 7 October 2024 (UTC)

Be careful about jumping to conclusions about who is copying who. It looks like the table in wikipedia (here it is in 2007: https://en.wikipedia.org/w/index.php?title=Collagen&oldid=113578136) predates that external article (first appears on the wayback machine in 2011) Pabnau (talk) 21:12, 21 June 2026 (UTC)

Collagen vs. Keratin

So my understanding is that: Collagen is the primary structural protein in cartilage, bone, and connective tissue, while keratin is the primary structural protein in hair and nails, and skin has a bit of both. However, the current article has a line where it says:

“Collagen is a protein in skin, hair, nails, and other tissues.” Citing: health.harvard.edu

Maybe I’m losing my mind, but it seems like there are multiple dermatologists out there making inaccurate claims about the composition of hair and/or nails. That source says: “(Collagen) also helps make up proteins such as keratin that form skin, hair, and nails,“ unless I’m missing something, this seems directly inaccurate: collagen is from the COL family of genes, Keratin is from the KRT family of genes. Maybe they meant to say that collagen has a lot of the amino acid proline which can help build Keratin?

Similarly, on the cleaveland clinic website, I found another dermatologist claiming that “Collagen is the primary structural protein that we find in cartilage, skin and hair” (emphasis mine) (https://health.clevelandclinic.org/collagen-for-hair-growth). Which, I think is also just unequivocally wrong? Keratin is the primary structural protein in hair, right? I can’t even find mention of collagen in papers discussing the structural composition of hair.

Honestly I’m not sure how to handle this kind of thing. Maybe I’ll send an email to the two sources to ask for clarification or correction. Pabnau (talk) 20:24, 21 June 2026 (UTC)

This 2025 review provides some clarity and skepticism about the fate of collagen after consumption as a dietary supplement: it is hydrolyzed into fragments which may then be substrates in skin regeneration (after burns or wounds, for example). If there's any benefit from a consumed collagen product, it comes from its components (which could be obtained through normal foods) rather than the intact protein.

This Medscape summary for keratin and collagen may help. Keratin is part of the intracellular cytoskeleton of epidermal keratinocytes, while collagen is the main protein of the dermis. A hair shaft is based on keratin, not collagen, which is in the root sheath and provides tensile support, but is not core material of hair fiber.

I'll look for other sources - it's a complex topic. Zefr (talk) 22:53, 21 June 2026 (UTC)

Yeah, from looking around some more and chatting with a biologist, I think you’re right. I think the source probably just wasn’t being too careful in some of their offhand comments. Collagen may be involved in supporting the hair root, but doesn’t appear to be part of the hair shaft itself Pabnau (talk) 00:09, 22 June 2026 (UTC)

Ok, I made the minimal change to make sure that sentence is accurate/clear by specifying that it’s in the skin around the hair follicle and nails. Personally, I don’t really want to delve into the morass of controversial treatments/supplements. As long as the article doesn’t increase public confusion of keratin vs. collagen, I’m satisfied Pabnau (talk) 00:36, 22 June 2026 (UTC)

As a supplement

this large review was recently added not sure if it is worth mentioning as we hardly mention supplement use in the article Carrot juice (talk) 22:20, 1 July 2026 (UTC)

The Aesthetic Surgery Journal is not MEDLINE-indexed, i.e., (unestablished reliability) and not an acceptable MEDRS source.

For use of collagen as a dietary supplement, this is a more skeptical assessment. Something can be stated in the article - will review and edit. Zefr (talk) 22:44, 1 July 2026 (UTC)

Added a section on use in foods, supplements, and topical products with Special:Diff/1362236695. Feel free to critique/edit. Zefr (talk) 18:06, 2 July 2026 (UTC)

Are you sure this isn't MEDLINE indexed. The Aesthetic Surgery Journal has two journals both are indexed with MEDLINE/PubMed according to the official The Aesthetic Society website. It says "ASJ Open Forum is indexed with MEDLINE/PubMed and covered by the Clarivate Journal Citation Report. ASJ Open Forum’s current (2024) Impact Factor is 1.9 and it is ranked 119 of 312 among all journals in the category Surgery. ASJ Open Forum ranks among the top third of all surgery journals". . I find it doubtful they would lie about this.

Also it says here in this press release ASJ and ASJ Open Forum are both indexed in MEDLINE/PubMed and included in Clarivate's Journal Citation Reports

The paper can be found here Carrot juice (talk) 20:14, 2 July 2026 (UTC)

Click on the highlighted journal title shown on the PubMed page, then click on "View in NLM Catalog". That is the result I used.

I find the conclusions warrant caution: "collagen supplementation demonstrates consistent and clinically meaningful benefits for dermal, bone, and muscular health", which seems outside of the clinical mainstream. I was unable to find a medical organization guideline that endorses supplemental collagen for any organ disease or preventive health effect, WP:MEDASSESS, top of left pyramid.

If including the 2026 review is justified, it could be added with a caveat per WP:BALANCE. Zefr (talk) 20:29, 2 July 2026 (UTC)

Sketchy Statistics?

There are a couple claims in the article that, from what I can gather, have a high likelihood of being false. Unfortunately, they are stated all over the place (often without citation), including off-hand comments in otherwise reliable sources.

• ”(Collagen) is the most abundant protein in mammals, making up 25% to 35% of protein content”
• “Over 90% of the collagen in humans is Type I and Type III collagen.”

I was trying to trace them back to their origins sometime earlier, and I failed, and then today I stumbled on this article: https://pmc.ncbi.nlm.nih.gov/articles/PMC10024738/ which directly calls out the first claim and this wikipedia page. They also tried to trace back that original claim, and found that it was based on some old, shaky evidence, and some other attempts (including their own) found about half as much.

Similarly, when I was investigating the second claim, it seemed like some paper up the chain had misquoted the fact that 90% of *bone* collagen is type I (while other tissues have less). The reported numbers in the above paper also seem to suggest that it isn’t correct, with Type VI + Type II together being about 1/3 as much prevalence of type I. This is from mice, but it appears that most of these statistics are coming from mice or other non-human animals.

We probably can’t cite the primary research from that article, and I haven’t been able to find a good review article of the question yet, but I feel like we need to be particularly careful with these two claims. The former claim doesn’t seem to have a reference, while the second claim cites what appears to be a book of review problems “Sabiston textbook of surgery board review, 7th edition. Chapter 5 wound healing, question 14,” which doesn’t seem like an ideal reference. I don’t have access to it, but other sources cite it as saying 90% is just type I collagen, so I’m also not sure where the type III part came from. Pabnau (talk) 02:43, 24 July 2026 (UTC)