What Mounjaro Feels Like: A Personal Trainer’s 8-Week GLP-1 Experiment
3/4 of one slice of pizza. Half a bottle of Corona. Done. STUFFED.
Friends had just helped me move apartments, and I did the classic thing. Pizza and beers for everyone.
On a normal day I'm the guy who can throw down a whole pizza by himself. That day I got halfway through a slice, forced down another bite or two because I felt like I had to and threw the crust out.
I was a few weeks into an experiment. I'm a full time personal trainer and nutrition coach, and I had put myself on Mounjaro (Zepbound), Ozempic's stronger cousin.
This is the full story. Why I did it, how easy it was to get, what it actually felt like, what happened to my body, and the thing it taught me that I didn't see coming.
Quick note before we start: this is not medical advice. This is my story. Whether you should or shouldn't take one of these drugs is a decision for you and your doctor.
Why would a personal trainer take a weight-loss drug?
Quick backstory. I started working out at 14. I was a chubby kid. Athletic, but I hated how my body looked. After a few years of trial and error, I changed it. Built a good physique and proved to myself I could do it.
Fast forward to working as a coach. Every week, clients ask me what I think about some supplement, some diet, some medication. Over the last few years one question took over all the others. What do you think about Ozempic?
You've probably seen the commercials. If you've watched an NHL or NFL game, you've been bombarded by them. You probably know someone who you saw six months later and they looked like a totally different person.
Honestly, I used to be very against these drugs. I thought they were a quick fix. A silver bullet for people who didn't want to do the work. I thought lazy people took them. My whole take was: "Just do it the right way. Don't be a bitch."
I'm not proud of that. But it's the truth, and it's where this story starts.
What changed my mind before I ever took it
The more I dug in, the shakier my opinion got. I read books on it. I spent well over 100 hours listening to podcasts and audiobooks about it. A few things kept coming up.
Genetics plays a big role. If you grow up with parents who have obesity, your own odds go up a lot. Some of that is genes. Some of it is the household you grew up in, the habits, the portions, the way food was used. Either way, you didn't pick it.
Money and access matter. Eating fresh, filling, nutritious, lower-calorie food is a lot harder when you can't easily get it or afford it. Cheap, highly processed food is convenient. There's a reason busy families, single parents and people on tight budgets lean on it.
None of that means people are helpless. It does mean the starting line isn't the same for everyone. And I started to wonder if I'd been judging a fight I'd never actually been in.
So I decided to find out.
How I got Mounjaro (it was easier than you'd think)
I went on an online pharmacy website and applied. That's it.
I'm 5'10". At the time I weighed about 199.5 lbs (after a big meal, at night time). By BMI alone, that puts me in the very overweight, nearly obese category. BMI doesn't know I'm 12-14% body fat and a very trained athlete. It just sees height and weight.
This was my physique at the time (May 2025)
Here's the night I weighed in (May 12, 2026) + a free shot of my feet... you're welcome
I filled out the forms and recorded a quick video of myself in a form-fitting shirt. About 30 minutes later, I was approved. A few days after that, the pen showed up at my door.
I'll be honest, that part surprised me. A healthy personal trainer training for a marathon got approved in half an hour. Take from that what you will.
How it works
Mounjaro (tirzepatide) comes in a small injection pen. When I did it, each pen held four doses. You inject yourself once a week. It works on the hormones that tell your brain you're full, so it turns your appetite way down.
They started me at 2.5 mg a week. After four weeks, I moved up to 5 mg a week. I stayed on it for 8 weeks total.
Why "Ozempic's stronger cousin"?
Ozempic is semaglutide. Mounjaro is tirzepatide. In a head-to-head trial, people on tirzepatide lost more weight than people on semaglutide.
Here's the simple version. When you eat, your gut releases hormones that tell your brain and body you've had enough. GLP-1 is one of those hormones. GIP is another.
An "agonist" is just a drug that copies a hormone and switches its signal on. Ozempic is a single agonist. It copies one hormone, GLP-1. Mounjaro is a dual agonist. It copies two, GLP-1 and GIP.
Think of it like having one friend tell you to put the fork down versus two. Two signals instead of one is likely a big part of why Mounjaro came out ahead in that trial.
What does Mounjaro actually feel like?
For the first week or two, I could barely eat. Here's how I describe it to clients.
Imagine you just ate two or three plates of turkey dinner at Thanksgiving. Your aunt walks up and says, "Want another plate? Just plain turkey and some vegetables. No sauce or gravy."
If you're a normal person like the rest of us, the answer is no thanks. Smothered in gravy with potatoes? Maybe. Dessert? Maybe there's room for apple pie with ice cream. But plain lean meat and vegetables? You're good. You're content.
That's what the drug felt like. All day. Every day.
The pizza night after the move is the moment I'll never forget. I shit you not, me, a guy who could eat a whole pizza if you dared him to...ate three quarters of a slice and half a beer, and genuinely did not want another bite. It NUKED my desire to overeat. For a while, it nuked my desire to eat at all.
Greasy, fatty food was the worst. Pizza, burgers, anything fried. It wasn't just that I didn't want it. It was physically hard to get down.
That also made it hard in a way I didn't expect. I was training for a marathon. I needed fuel and couldn't stomach food. I ended up drinking multiple cans of Fanta a day.
Each one packs close to 50 g of sugar, and it was the easiest way I could find to keep my calories up. Trying to eat enough while training that hard on this drug was very, very difficult.
Food noise: the part nobody talks about
Here's the thing about me. I've been incredibly food motivated my whole life. If I were a golden retriever, you could train me with treats. I'd be the easiest dog in the world. Give me a snack, tell me to sit, done.
The way I explain food noise is a radio. At 10 out of 10, it's blaring. You think about food constantly. At 1 out of 10, you can barely hear it.
My whole life, my radio has played at a 7 or 8. I was the kid who always cleaned his plate. That's a big part of why I was chubby. Most of my family has struggled with obesity their whole lives too.
On the drug, early on, my food noise dropped to a 1.
For the first time in my life, the radio was basically off. Bad day and want comfort food? Didn't care. Night out for drinks with friends? Not appealing. It was weird. I'd never felt anything like it.
As my body got used to the drug, which it does, the radio crept back up to a 2, maybe a 3. Still way quieter than my normal.
And that's when it hit me. Some people walk around with that radio at a 2 their whole lives. Some people hear it at a 10, every single day. Most of us assume everyone hears it at the same volume we do.
My results: almost 30 lbs in 8 weeks, then what happened after
I started at about 198 lbs. At my lowest, I got down to 170 to 172 lbs. Almost 30 lbs in 8 weeks, while training for a marathon.
After I came off it, I ran the marathon and set a personal best: 2 hours and 53 minutes.
The funny part? Leading up to it, my clients kept telling me I looked gaunt and unhealthy. A few of them wanted to buy me a burger. Not exactly the look a trainer is going for.
Over the next three to six months, I stopped tracking my food. I got back into heavier lifting. My body drifted back to the weight it likes to be, around 190 to 195 lbs.
I'm sharing that part on purpose. When I stopped, the weight came back. My body has a set point it likes, and it went right back to it. (If keeping weight off is your fight, I wrote about that here: Why Most People Regain the Weight.)
What I took from it
I'm not telling you to take a drug. I'm not telling you not to. That's between you and your doctor.
So where do I land now? I'm not exactly pro or anti GLP-1 drugs. They can be a positive, powerful tool that can quite literally save someone's life. They can just as easily be abused and lead to bad outcomes. Like a lot of things in life, it depends.
Here's what I am telling you. Curiosity is my superpower. Before I passed final judgement on these drugs, I wanted to know what they were actually like. Now when a client asks me about them, I can show up to that conversation with something real. Books, research, and eight weeks of living it.
And the biggest lesson had nothing to do with weight.
The way you experience the world is not the way everyone else does. Just because it's easy for you to stop eating when you're full, or not buy the food, or skip the second drink, doesn't mean it's easy for the person next to you. Everyone's wiring is different under the surface.
Same goes for the people in your life. Your spouse. Your friend. The guy on your team who can't seem to get it together. You don't know how loud their radio is.
This experiment made me more compassionate. It made me a better coach. And it reminded me to stay curious before I dig in on a belief.
I think the world would be a better place if more of us questioned our own beliefs and were willing to be wrong.
I was. And I'm better for it.
FAQ
What is Mounjaro?
Mounjaro is the brand name for tirzepatide, a once-weekly injection in the same family as Ozempic. It turns down appetite by acting on the hormones that tell your brain you're full.
Is Mounjaro stronger than Ozempic?
In a head-to-head trial, people on tirzepatide (Mounjaro) lost more weight than people on semaglutide (Ozempic). Mounjaro acts on two gut hormones, GLP-1 and GIP. Ozempic acts on one, GLP-1.
What does food noise mean?
Food noise is the constant background chatter in your head about food. Wanting it, planning it, thinking about it. Some people barely hear it. Others hear it all day.
How much weight did you lose on Mounjaro?
Almost 30 lbs in 8 weeks, from about 198 to 170 to 172 lbs. I was also training for a marathon at the time.
Did the weight come back after stopping Mounjaro?
For me, yes. Within three to six months of stopping, I was back around 190 to 195 lbs.
Are you for or against GLP-1 drugs?
Neither, really. They can be a powerful tool that saves lives, and they can be abused. It depends on the person and the situation.
Should I take Mounjaro or Ozempic?
That's a decision for you and your doctor. This is my story, not medical advice.
Is Mounjaro the same as Zepbound?
Yes. Both are tirzepatide. Zepbound is the brand name used for weight loss in the US. In Canada, it’s sold as Mounjaro.
Is Ozempic the same as Wegovy?
Yes. Both are semaglutide. Wegovy is the higher-dose version approved for weight loss.
Resources
The books and podcasts I went through before and during this experiment.
On GLP-1 drugs:
Magic Pill by Johann Hari
Diet, Drugs, and Dopamine by David A. Kessler
Related:
Ultra-Processed People by Chris van Tulleken. This one helped me understand how systemic the ultra-processed food we've gotten hooked on really is. How powerless some people are against it, and how much money and sinister intent can be behind it.
Podcasts (for audio learners):
GLP1 Podcasts, my Spotify playlist. About 20 hours of episodes on these drugs. It runs from the story of Novo Nordisk, the company behind Ozempic (great if you're into business), to critical takes from The Tucker Carlson Show and Rich Roll, to more positive ones from Johann Hari and Dr. Tina Moore. Listen to both sides and make up your own mind.
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