Quick number for context: scale down 2.1 lbs last month, but my waist measurement dropped 0.8 inches. I’ve seen this pattern before and I think the half-life math explains some of it. Tirz has roughly a 5-day half-life. Peak GIP/GLP-1 activity lands somewhere in the 24-72 hour post-injection window - that’s also when appetite suppression is strongest for most people, including me. I started logging my protein grams vs injection day about four months ago and found something I didn’t expect: my protein intake reliably drops 15-20g on injection day and the day after. Not because I’m trying to, just because I’m not hungry. Hypothesis: if you’re losing fat but also shortchanging protein in the highest-activity window, you’re leaving muscle preservation on the table. The scale won’t always show the difference, but body composition will over time. What I changed: I now front-load an extra 20-25g protein the day before injection - usually cottage cheese or eggs, nothing fancy. Five weeks in, CGM lines are identical, but the tape measure is moving faster than before. Not a recommendation, just what I’m running. Anyone else tracking protein intake relative to injection day?
week 18 on semaglutide so the half-life and peak window are different from your tirz math, but that injection day protein dip you’re naming is so real. food noise drops hardest around day 1-2 post-injection, and my protein intake just tanks 15-20g w/o even trying. front-loading before injection makes total sense - you’d be catching that window before the suppression hits. scale stayed flat this week but the tape moved, so body comp is definitely happening. have you noticed if the protein timing effect stays consistent as you increase dose, or does the window shift?
that protein dip is real - week 18 on sema so the timing window is different, but same pattern holds. days 5-6 post-injection i’m definitely not hitting my protein target without planning ahead… pattern wouldn’t even be visible without tracking week-to-week. front-loading before peak suppression beats white-knuckling it after the fact. ngl even a few grams of muscle preserved per week compounds over 16-20 wks. tape measure moving matters way more than scale numbers on this, and that’s honestly the whole point of actual body recomp.
mechanics check out. suppression peaks days 2-3 for me too, protein intake just doesn’t happen. front-loading before that window means you’re not fighting a 15g deficit when appetite suppression hits hardest. tape measure moving faster is honestly the signal that matters. n=1 but i track the same way, pattern holds.
The sema half-life being longer (~7 days vs tirz’s 5) is actually interesting for your question, because it might mean your suppression trough is shallower but the tail is longer. My day 1-2 window is pretty sharp and then I get a clearer rebound by day 4-5. If your curve is flatter, the protein dip might be more spread across the week rather than concentrated, which could actually make front-loading harder to time precisely. On your dose question: I went from 2.5mg to 5mg about eight months ago. The window didn’t shift much for me, roughly the same 24-48 hour appetite floor, but the depth got worse. Meaning, at 2.5mg I could still push through and hit my protein targets on injection day with effort. At 5mg, front-loading the day before became basically required rather than optional, bc trying to eat 140g protein while nauseous is a losing game. What I don’t have is data past 5mg since that’s where I’ve stayed. If you’re still increasing dose, I’d track the dip window specifically over the first two weeks after each adjustment, not just the average. That’s where I found the most signal in my own spreadsheet. The window length stayed stable for me but the floor dropped. Scale flat, tape moving is exactly the right outcome to be chasing right now, fwiw.
that tracking-window-specifically insight is gold. i’m stable at my current dose (compounded sema, no adjustments planned) so i can’t speak to what the depth change feels like, but yeah, the spreading-across-the-week thing tracks with what i’m seeing. my dip is softer and longer than you’re describing, days 5-6 are the real hunger rebound for me. the “scale flat, tape moving” framing is exactly it though. week 18 and my knees don’t hurt on stairs anymore - that’s the win i actually notice. scale will do what it does, but the waistband tells the real story. are you tracking your dip window on a spreadsheet or just mental notes?
the “front-load the day before” approach is what I landed on too, but I got there from a different direction. my CGM showed a reliable glucose dip starting around hour 18 post-injection, which meant my appetite was already tanked by the time I needed to hit protein targets. so I moved my higher-protein meals to injection eve intentionally. lean mass loss on DEXA at month 9 was ~2.1 lb, which my endo and I both think would’ve been worse without that adjustment. the pre-injection window is genuinely underused.
your appetite pattern is solid, but the day-before pre-load is probably hedging rather than optimizing - that protein’s already absorbed by the time peak suppression hits, so you’re not actually eating during the 24-72 window. the behavioral win is real though. harder question: is the faster tape movement from the pre-load specifically, or from being more deliberate about protein logging overall?
five weeks isn’t long enough to separate those. might be worth a control week in a month to see