Tuesday Turbulence
My stomach has been churning since last night's dinner, and it's not the first Tuesday that's happened. The timing turns out to make a surprising amount of sense once you look at how long tirzepatide actually sticks around.
Today is Tuesday, and that means turbulence. My stomach’s been churning since last night’s dinner, and I woke up to more of the same, with a bit of discomfort on top. This seems to be the way of Tuesdays now.
It’s not a one-off. Friday’s injection, a relatively manageable weekend, and then, like clockwork, the churning turns up on Tuesday. Roughly four days after the jab. Close enough to the middle of the seven-day cycle that I started wondering if that’s actually significant, or just a coincidence I’ve talked myself into.
Tirzepatide has a half-life of around five days, which is the whole reason Mounjaro gets to be a once-a-week injection instead of something more frequent. So the middle of my dosing week did feel like it should mean something.
Except the middle of the interval isn’t the same as the point where the drug is doing the most. According to the prescribing information, peak concentration after a dose is typically reached somewhere between 8 and 72 hours, with 24 hours being the median. So by Friday evening into Saturday, I’m probably near the peak, not on Tuesday. By Tuesday the concentration is already on its way down. There’s just still a lot of it left, because a five-day half-life doesn’t let go of anything quickly.
So “Tuesday is the middle of the cycle” turns out to be true, but it’s not actually the reason for the turbulence. If there’s a reason, it’s somewhere else.
A few more plausible explanations than “peak drug day”:
Delayed gastric emptying. Mounjaro slows down how fast food leaves the stomach, especially in the earlier months of treatment, so dinner can still feel like it’s being dealt with long after I’ve gone to bed.
A cumulative effect. On a weekly injection, the drug never fully clears before the next dose arrives. Whatever it’s doing to my gut doesn’t get a clean week off in between.
Plain individual quirkiness. My gut might just have its own schedule that doesn’t map neatly onto a concentration graph at all.
I’m still on 2.5 mg, several months in, which is a world away from the 5 mg dose that caused a genuinely bad reaction earlier on. This isn’t that. It’s trapped wind, churning, a nagging discomfort that’s there all morning and then isn’t. Manageable. A nuisance rather than an event. Tuesday turbulence, not Tuesday catastrophe.
That distinction matters, because it’s the bit worth actually paying attention to. Trapped wind and churning are unpleasant but ordinary. Persistent or worsening abdominal pain, especially if it radiates to the back, or comes with repeated vomiting, is a different category entirely and gets assessed properly, not written up as a diary entry.
What I don’t know yet is whether it’s really the jab’s timing driving this, or just what I happen to eat on Monday evenings. Those are two different culprits, and the only way to tell them apart is paying attention over a few more weeks rather than one.
For now, though, the Mounjaro diary has acquired a dependable weekly entry. Tuesday: stomach grumbling, trapped wind, mild discomfort. Usual service resumed. Scales said 14 st 4 lb this week, so whatever my gut’s doing, it hasn’t managed to get in the way of that.