For the first one, I assume you mean a systematic review, not a peer review? I guess you're talking about this one:
https://pmc.ncbi.nlm.nih.gov/articles/PMC10180699/
It has a Mechanism section which explains that when collagen is digested, one of the products of that is Gly-Pro-Hyp, which is what has the effects. I don't think that conflicts anything in this post?
I assume they're referring to the brief bit in the post that indicates that oral ingestion leads to a breakdown that makes oral supplements of amino acids pointless. They say it very briefly and they don't really outright assert it, it's just a sort of implied aside.
Here is the exact quote:
Every single YouTube video and blog post I have read about peptites is exclusively about injectable supplements.That's not the exact quote lol you cut out the exact part I was referring to.
> because unless a really substantial amount of engineering has gone into it, any given peptide is going get the same treatment from your digestive system as a chicken breast does, i.e. a complete teardown
> Every single YouTube video and blog post I have read about peptites is exclusively about injectable supplements.
Collagen peptides, ghk-cu, and many other peptide supplements are often taken orally.
Sweeping statements in biochemistry must be made with caution. It is well known that there are some small peptides that are absorbed following oral administration.
...BPC-157 itself is said to be among this class. As are certain milk tripeptides: https://en.wikipedia.org/wiki/Lactotripeptides
Interestingly enough, those two, as well as Gly-Pro-Hyp, are proline/hydroxyproline-rich, which might suggest that proline-rich small peptides are resistant to degradation in the gut.
Anyway, in general oral proteins and peptides are broken down prior to systemic absorption, but not always...
> It is well known that there are some small peptides that are absorbed following oral administration. ...BPC-157 itself is said to be among this class
Do you know of any studies that suggest BPC-157 absorption from gut?
https://onlinelibrary.wiley.com/doi/abs/10.1002/jor.21107
Among others. If you read the paper, it's actually apparent that there's little difference between i.p. and oral administration in terms of efficacy -- both were roughly equally effective in improving MCL ligament healing.
Admittedly the paper's in rats -- as are 99% of the others -- as there's no incentive for anybody to run human trials.
I'm in agreement. It's the article that made the sweeping statement.