Five months on Mounjaro: an ops manager's debrief

I’m 45 in two days. Older dad. Two kids under three, partner ten years younger than me, and the last two years have been the most tired I’ve ever been. Going to work tired. Eating tired. Fast sugars, vending machines at three o’clock, the usual.

In the first week of January 2026 I started Mounjaro. New year, new me. I’d been turning the idea over for months and ran out of reasons not to. Five months in, I’ve gone from 106kg to 86-87kg. I’m on 10mg, third week of it, and I’ll either stay on 10 or step back to 7.5 next month. Final number will be wherever the mirror tells me.

This piece is a debrief, written the way I’d write up a Lean project at work. Baseline. Dose progression. Side-effect register. What I’d do differently. What I’d tell the next person.

The decision: why now

I’d been at this weight before, in my early thirties, and got down to mid-80s through walking, the gym, and calorie restriction. It worked. I felt great. The dopamine hit of seeing the scale drop because I’d put the graft in was massive.

This time was different. Two young kids, broken sleep for the best part of two years, partner ten years younger and tired in her own way, a long working week. The gym-and-graft route had been on the cards for eighteen months and hadn’t started, because there was no time and no slack in the system to start it. Every Sunday night I’d plan the week and every Tuesday it was on its arse.

What changed was a shift in how I thought about the tool. Mounjaro isn’t a way out of doing the work. It’s a way to take the food noise out of your head for long enough that you can do the rest of the work. The food noise (the constant low-level “what shall I eat next” running in the background) is what was burning the daily willpower I needed for the kids, the job, everything else.

I started 2.5mg in the first week of January. The plan was to step up on the standard cadence, get to 10mg by month five, then review.

The dose progression and what each one felt like

The protocol is straightforward. Four doses, four weeks each as a minimum, step up when your body is ready.

• 2.5mg (month one). Surprisingly easy. The first injection itself: painless, took five minutes, came in the post the next day. The first 24 hours after the first jab were the hardest of the whole five months. Couldn’t eat. Chewing food felt strange. Hoped the food aversion would repeat every dose; it didn’t. Just the first month. Slept well. Lost 6kg in four weeks because the body was suddenly absorbing a fraction of what it had been.

• 5mg (months two and three). This was the hard step. Dose doubles. Nausea came back hard. Fatigue. The kind of background-tired where you’d happily skip dinner because you can’t be bothered. I stayed on 5mg for two months instead of one because the side effects were enough to keep me there. By the end of month three I’d dropped another 8kg.

• 7.5mg (month four). Easier transition. Smaller proportional jump. Body had got used to the mechanism. Side effects still there (constipation in particular, which I’ll come back to), but the nausea was largely gone. 4kg in the month.

• 10mg (month five, three weeks in). Currently here. Side effects mild. Hunger almost entirely absent. The challenge now isn’t appetite. It’s making sure I eat enough on a schedule. Another 2kg so far.

Total: 20kg in five months. Numerically clean. Felt nothing like clean from the inside.

What I wish I’d known before the first jab

Four things I’d put on the noticeboard if I were briefing my past self.

1. The 2.5 to 5mg jump hits like a truck. The dose doubles. The next jumps aren’t really doubling, but that one is. Plan for it. Move it to a weekend if you can. Don’t try to power through a big work week on the first ten days of 5mg.

2. Water and electrolytes are a second monthly subscription. You’ll get headaches if you don’t hydrate. You’ll get bored of plain water within two weeks. Electrolyte drinks aren’t cheap and the cheap ones are gritty. Find one you’ll actually drink. Stock up. The medication isn’t the only line on the budget. (Plan for the electrolyte cost when you plan for the prescription cost. It’s not optional.)

3. You will get hangry without knowing it. The appetite tool dulls the hunger signal so well that you can skip eating for hours without noticing. Then somebody asks you something at work and you bite their head off. Only way I knew was that I got feedback from a colleague that I was sharper and snappier than usual. Stick to routines. Breakfast at the same time. Lunch at the same time. Mid-afternoon snack at the same time. Fuel the body even when the body isn’t asking.

4. The psychological dopamine hit isn’t there. This is the one that surprised me most. Last time I was this weight, the confidence was through the roof, because every kilogram off was the result of work I could see. This time, the kilograms come off and I don’t feel different about myself in the same way. The scale moves; the reward circuit doesn’t fire. It’s not cheating, but it isn’t the same psychological win, and you should know that going in.

The side effects nobody warns you about

In rough order of how much they affected my week:

• Constipation. This was the worst of the lot. Not painful, just persistent. Feel like you need to go, sit down, nothing much happens. Drink more water than you think you need, eat fibre even when you’re not hungry, and accept that this one doesn’t entirely go away.
• Hangry without knowing it. Covered above. The hidden one.
• Fatigue on the 2.5-to-5 jump. The kind that makes you want to lie on the sofa at 7pm.
• Food aversion to specific things. Coffee tasted weird for the first month. Rich foods tasted off. Most of this settled by month three.
• Sleep, weirdly, was better in the first month. Not sure if this was the medication or the weight coming off, but I slept harder and woke less in month one than I had for a year. Cannot overstate the compound effect of one decent month of sleep when you’ve been running on broken sleep for two years.

What I’d do differently if I started again

Start sooner. Six months sooner would have meant I’d be at the final number by my 45th. I waited longer than I should have because the medication was new-ish, the side effects had a reputation, and I half-believed the “easy way out” voice in my own head. None of that was a good enough reason to wait.

Pre-stack electrolytes and a fibre source. Order them at the same time as the first month’s prescription. Don’t try to find them on day three of side effects.

Tell my partner before the first injection what to expect. I didn’t, properly. Astrid bore the brunt of the mood dip in the first two weeks of 5mg. If I’d briefed her (“I might be sharper than normal for ten days, please tell me if I am”) we’d have both navigated it better.

Eat to a schedule from day one. Don’t wait until the hangry feedback comes from work.

Plan for the dopamine gap. Don’t expect the psychological lift you got the last time. Treat the scale moving as a clinical signal (same as you would a temperature gauge on a process) not as a daily reward. The reward is the downstream stuff: sleep, knees, energy, what you fit into, how you keep up with the kids. Tracking the downstream stuff weekly was what kept me on it through the second month, when the scale alone wasn’t doing the work.

The lean lens, applied to a personal protocol

I treated the whole thing like a lean project. Not because that’s clever or because it makes a good blog post. Because that’s how my head works after twenty years of doing this for other people’s sites.

• Baseline: 106kg, knees aching, broken sleep, sugar cravings at three.
• Improvement hypothesis: Reduce appetite signal → reduce daily calorie load → reduce weight → improve sleep / knees / energy.
• Standard work: Weekly injection on the same day. Breakfast / lunch / mid-afternoon snack at fixed times. Electrolytes daily. Weigh-in once a week, same morning, same scales.
• Side-effect register: Tracked the bad week of each dose jump so I could anticipate the next.
• Control plan: When the scale moves more than expected in either direction, check the eating schedule first, the hydration second, the dose third.

That’s not the framework someone trained me in. That’s the framework that’s in my head after running it on other people’s problems for two decades. The Lean lens works on yourself if you let it. It doesn’t make the work easier. It just stops you skipping the steps that matter.

To a 40-year-old man on the fence

Start sooner.

The side effects are real but manageable. The cost is real but quantifiable. You can budget for it. You can plan for it. You can absorb the worst of it in a weekend.

The benefits compound. Twenty kilograms in five months changes how your knees feel walking up the stairs. It changes how long you can play in the garden with a toddler. It changes the readings on the next blood test. It changes whether the air conditioning at work bothers you. It changes how you look in the mirror on a Sunday morning, even if the dopamine hit isn’t the same as the last time you did it the hard way.

The medication’s been around long enough now that the worst-case scenarios have largely been ruled out. Talk to your GP. Find a reputable supplier. Read the protocol. Plan for the first dose jump.

Then start. Don’t wait for a perfect month. There isn’t going to be one.

What this has to do with Cadence Standard

Most things I write here are about operations work: Lean, SMED, 5S, the rhythm of running a site or a department. This one isn’t, on the surface.

It is, underneath. The bit that makes a real difference, in operations or in your own life, isn’t the framework. It’s having the discipline to run the framework when it gets boring, when the side effects bite, when the dopamine hit isn’t there to keep you doing it.

Pick your battle. Fix the right thing first. Measure baseline. Run the protocol. Track the side effects. Keep the cadence. Don’t break in month three.

It works on a £40k-a-week changeover. It works on a 20kg weight loss. Same operator, different problem.

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