pslfinalboss
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I’ve seen a few people say glucosamine can lower IGF-1 or make you “less sensitive” to it, this isn’t true because that theory comes from cell studies using crazy-high doses of glucosamine. Not actual humans taking 1500mg a day for their joints.
The idea behind why people claim glucosamine hinders IGF-1
This study used HepG2 liver cancer cells and dumped like 20mM glucosamine on them for 18 hours. That’s not even remotely close to what you get from a supplement. They saw reduced IGF-1 receptor phosphorylation:
[https://pubmed.ncbi.nlm.nih.gov/12746299/](https://pubmed.ncbi.nlm.nih.gov/12746299/)
Another study in lung cancer cells showed glucosamine reducing IGF-1R/Akt signaling:
[https://www.ncbi.nlm.nih.gov/pmc/ar...ww.ncbi.nlm.nih.gov/pmc/articles/PMC3901559/)
People saw these and jumped straight to “glucosamine will kill your gains and lower IGF-1.”
What’s actually true:
Human clinical data doesn’t really show meaningful changes in serum IGF-1 from normal glucosamine doses. This joint trial showed about a 5% increase in IGF-1 that wasn’t even statistically significant:
[https://bmccomplementmedtherapies.b...dcentral.com/articles/10.1186/1472-6882-7-34)
There’s just no strong evidence that glucosamine reduces systemic IGF-1 in healthy people.
Why the cell studies are unreliable
* The doses are insanely high compared to what supplements give you
* Cancer cells don’t equal normal human physiology
* Inhibiting receptor signaling in a petri dish isn’t the same as lowering your IGF-1 hormone levels in real life
Tldr
Glucosamine = fine for joints, basically no impact on IGF-1 in regular humans. The scare comes from petri dish data on cancer cells using doses you’ll never reach. If you’re taking 1500mg/day, you’re fine.
The idea behind why people claim glucosamine hinders IGF-1
This study used HepG2 liver cancer cells and dumped like 20mM glucosamine on them for 18 hours. That’s not even remotely close to what you get from a supplement. They saw reduced IGF-1 receptor phosphorylation:
[https://pubmed.ncbi.nlm.nih.gov/12746299/](https://pubmed.ncbi.nlm.nih.gov/12746299/)
Another study in lung cancer cells showed glucosamine reducing IGF-1R/Akt signaling:
[https://www.ncbi.nlm.nih.gov/pmc/ar...ww.ncbi.nlm.nih.gov/pmc/articles/PMC3901559/)
People saw these and jumped straight to “glucosamine will kill your gains and lower IGF-1.”
What’s actually true:
Human clinical data doesn’t really show meaningful changes in serum IGF-1 from normal glucosamine doses. This joint trial showed about a 5% increase in IGF-1 that wasn’t even statistically significant:
[https://bmccomplementmedtherapies.b...dcentral.com/articles/10.1186/1472-6882-7-34)
There’s just no strong evidence that glucosamine reduces systemic IGF-1 in healthy people.
Why the cell studies are unreliable
* The doses are insanely high compared to what supplements give you
* Cancer cells don’t equal normal human physiology
* Inhibiting receptor signaling in a petri dish isn’t the same as lowering your IGF-1 hormone levels in real life
Tldr
Glucosamine = fine for joints, basically no impact on IGF-1 in regular humans. The scare comes from petri dish data on cancer cells using doses you’ll never reach. If you’re taking 1500mg/day, you’re fine.
