bananablack said:
Shittersfull said:
Your meaning comes across loud and clear. Early in my own education (not long ago at all) I watched that guy's reta video. Much the same pitch - "it's way better than just wight loss" - and it opened my eyes. So I began researching, and everywhere people say the same: "helps with all kinds of great things"
Which probably explains why few people have replied to this thread - the information is already sitting here. A search will find it.
What I question, though, is whether tirz is responsible for all these great things, or the weight loss is - with tirz merely being the tool that makes the weight loss possible?
Proving it realistically, I do not think, is possible. Two options occur to me:
1. A group of people would have to eat as if on tirz, but without it. Cheating would have to be impossible, which means an inpatient study is the only route. Then compare against the tirz group.
2. Take a group on tirz and have them eat as though they were not on it. Compare them with people not on tirz who eat identically. Who would sign up for that? It sounds nearly impossible.
And what of all the non- responders? Where tirz does not curb their appetite, do the other benefits still arrive?
There's some tirz non responders here. Perhaps they can chime in? I think I know the answer, but I hope I'm wrong...
That's a solid question, and it's the one worth asking. The brief version: both are almost certainly at play, and the data keeps tilting toward genuine effects that don't depend on weight, rather than "losing fat just repairs everything."
The heart failure evidence is where the case is strongest. In the SUMMIT trial (NEJM), obese HFpEF patients were randomized to tirz or placebo, and over roughly 2 years there were actual reductions in the composite of CV death/worsening HF. What's relevant to your question, though, is this: multiple GLP-1/GIP mechanistic reviews note that tirzepatide lowers pericardial and epicardial fat, reduces cardiac inflammation, and improves chamber compliance in ways exceeding what body weight alone would predict. GLP-1 receptors are also expressed directly in heart tissue, brain, kidney, and gut, so a plausible direct-signaling route exists that doesn't need the scale to budge at all.
As for your non-responder question, that is in fact the cleanest natural experiment available to us. Should people who don't drop meaningful weight on tirz still demonstrate improvements in blood pressure, lipids, or inflammatory markers, that would be strong support for a weight-independent mechanism. In these communities, anecdotal reports from low/non-responders do include some blood pressure and triglyceride improvement, yet at a clearly smaller magnitude, consistent with a model in which weight loss carries much of the load but isn't the entire story.
The study design you propose (matched caloric restriction without the drug vs. drug-driven weight loss) is essentially what some rodent pair-feeding studies have used, and even in those, drug groups continue to show benefits beyond what pair-fed calorie-matched controls receive. So this isn't merely theoretical, actual pair-feeding literature exists suggesting a genuine independent drug effect, at least in animal models. Human RCTs that isolate the two variables are as difficult as you described, which is precisely why the field relies on these indirect approaches instead.
