Zepbound is the obesity-specific brand name for tirzepatide — the same molecule sold as Mounjaro for type 2 diabetes. It is a once-weekly injection that activates two gut hormones (GIP and GLP-1) instead of one, which is why it has produced the largest weight-loss numbers of any approved drug to date.
As of 2026 it is approved and available in Canada for weight management. In the head-to-head SURMOUNT-5 trial it beat Wegovy (semaglutide), with about 20% average weight loss versus roughly 14%. Below: what Zepbound is, how to actually get it in Canada, how it stacks up against Wegovy and Mounjaro, and where the research-peptide version fits (and does not).
What Zepbound is
Zepbound is tirzepatide, made by Eli Lilly. The confusing part for most people is the branding: the exact same molecule is sold under two names. As Mounjaro it is approved for type 2 diabetes; as Zepbound it is approved for weight management in people with obesity or overweight with a weight-related condition. Same drug, same pen, different label and different approved use.
What makes tirzepatide different from Ozempic and Wegovy is that it is a dual agonist. Semaglutide (the molecule in Ozempic and Wegovy) activates one receptor, GLP-1. Tirzepatide activates two — GLP-1 and GIP — and that second lever appears to translate into more appetite suppression and more weight loss for most people. We break the mechanism down further in tirzepatide vs semaglutide.
Is Zepbound approved in Canada?
Yes. Tirzepatide has been available in Canada as Mounjaro for some time, and Zepbound — the obesity brand, including the multi-dose KwikPen — became approved and available in Canada in 2025. In practice that means a Canadian doctor can prescribe tirzepatide for weight management, and it is dispensed through pharmacies like any other prescription drug.
Two practical notes. First, coverage is the usual Canadian story: public plans rarely cover weight-loss drugs, and private coverage varies, so many people pay out of pocket. Second, supply of these drugs has been tight worldwide, which is part of why a grey market of compounded and “research” tirzepatide exists — more on that below. For the regulated route, Zepbound is a prescription, full stop. For the landscape around generics and cheaper access, see generic Ozempic in Canada.
Mounjaro and Zepbound are the same molecule wearing two different name tags — one for diabetes, one for obesity. Knowing that saves a lot of confusion at the pharmacy counter.The single most useful fact about tirzepatide branding
How well it works
Tirzepatide holds the current record among approved weight-loss drugs. In the pivotal SURMOUNT-1 trial, adults with obesity lost an average of up to about 20.9% of their body weight over 72 weeks at the highest dose — numbers that used to be associated only with bariatric surgery.
The question everyone actually asks is “is it better than Wegovy?” For the first time, there is a direct answer. The SURMOUNT-5 head-to-head trial pitted tirzepatide against semaglutide and reported roughly 20.2% average weight loss for tirzepatide versus 13.7% for semaglutide over 72 weeks. Tirzepatide won, clearly.
| Trial | Drug | Avg weight loss | Duration |
|---|---|---|---|
| SURMOUNT-1 | Tirzepatide (highest dose) | ~20.9% | 72 weeks |
| SURMOUNT-5 (head-to-head) | Tirzepatide | ~20.2% | 72 weeks |
| SURMOUNT-5 (head-to-head) | Semaglutide | ~13.7% | 72 weeks |
| STEP-1 | Semaglutide | ~14.9% | 68 weeks |
Averages hide a lot of individual variation — some people lose far more, some far less — but the pattern is consistent: on average, tirzepatide out-loses semaglutide.
Zepbound vs Wegovy vs Mounjaro
| Zepbound | Mounjaro | Wegovy | |
|---|---|---|---|
| Molecule | Tirzepatide | Tirzepatide | Semaglutide |
| Receptors | GIP + GLP-1 | GIP + GLP-1 | GLP-1 |
| Approved for | Weight management | Type 2 diabetes | Weight management |
| Dosing | Once weekly | Once weekly | Once weekly |
| Avg weight loss | ~20% | ~20% | ~14-15% |
In short: Zepbound and Mounjaro are the same drug, and both out-perform Wegovy on weight. If you want the branded head-to-head in plain English, that is Mounjaro vs Ozempic.
What to know before asking your doctor
The most common side effects are gastrointestinal — nausea, diarrhoea, constipation, reflux — especially while the dose is being increased. They tend to ease over time. Less common but serious concerns, including pancreatitis and gallbladder issues, are why this is a prescription drug with medical supervision, not something to self-source.
Zepbound is a prescription medicine. Dose selection, titration and monitoring are decisions for your doctor — this article does not provide dosing guidance. If you are considering a weight-management drug, that conversation is the right first step.
Zepbound vs research tirzepatide
Because Zepbound is expensive and sometimes hard to get, people searching for tirzepatide inevitably run into “research” tirzepatide sold by peptide suppliers — TrueLabs included, where it is listed as TZ-2. It is worth being completely clear about the difference.
Zepbound is a finished, regulated pharmaceutical: a known dose in a sterile auto-injector, manufactured to pharmaceutical standards, prescribed and monitored by a clinician. Research tirzepatide is a raw compound sold for laboratory study, not a medicine, not dose-formulated for people, and not something a researcher should treat as interchangeable with the drug. The molecule may be the same on paper, but the regulatory status, the formulation and the oversight are not. For the honest trade-offs around sourcing, read Canadian vs imported peptides and how to spot fake peptides.
Zepbound myths
“Myth: Zepbound and Mounjaro are different drugs.”
They are the identical molecule, tirzepatide. Only the brand name and the approved use differ.
“Myth: Zepbound is not available in Canada.”
It is. Tirzepatide has been available as Mounjaro, and Zepbound became approved and available for weight management in Canada in 2025.
“Myth: You keep the weight off automatically after stopping.”
Trials show much of the lost weight tends to return after stopping, as with other GLP-1 drugs. These are treatments for a chronic condition, not a one-time course.
“Myth: Research tirzepatide is just a cheaper Zepbound.”
No. It is an unapproved raw compound for lab use, without the dose, formulation or oversight of the prescription drug. Treating the two as the same is a mistake.
For researchers
TrueLabs supplies tirzepatide as TZ-2 from $73, retatrutide as RT3 from $90, and Cagrilintide from $40, all in CAD for in vitro and laboratory research only. If your work involves incretin biology, these are the current frontier compounds. Before ordering, see how to read a peptide COA and the COA library.
FAQ
Tap a question to reveal the answer.
Is Zepbound available in Canada?
Yes. Tirzepatide is available in Canada, and Zepbound — the brand approved for weight management — became available in 2025. A Canadian doctor can prescribe it and it is dispensed through pharmacies.
What is the difference between Zepbound and Mounjaro?
They are the same molecule, tirzepatide. Mounjaro is approved for type 2 diabetes; Zepbound is approved for weight management. Same drug, different brand and indication.
Is Zepbound better than Wegovy?
On weight loss, yes, on average. The head-to-head SURMOUNT-5 trial reported about 20.2% loss for tirzepatide versus 13.7% for semaglutide over 72 weeks.
How much weight can you lose on Zepbound?
In the SURMOUNT-1 trial, average loss at the highest dose was up to about 20.9% over 72 weeks. Individual results vary widely above and below that average.
Is Zepbound covered by insurance in Canada?
Often not. Public plans rarely cover weight-loss drugs, and private coverage varies, so many Canadians pay out of pocket. Check your specific plan.
What are the main side effects?
Mostly gastrointestinal — nausea, diarrhoea, constipation and reflux — particularly during dose increases. They usually ease over time. Serious effects are why it requires medical supervision.
Is research tirzepatide the same as Zepbound?
No. Research tirzepatide (such as TrueLabs’ TZ-2) is a raw compound for laboratory use, not a dose-formulated, regulated medicine. The molecule may match, but the status, formulation and oversight do not.
Do you regain weight after stopping Zepbound?
Trials show much of the lost weight tends to return after stopping, as with other GLP-1 drugs. It is managed as a chronic treatment rather than a short course.
Related reading
- Mounjaro vs Ozempic
- Tirzepatide vs semaglutide
- Generic Ozempic in Canada
- Weight-loss injections in Canada
- Canadian vs imported peptides
References
- Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). N Engl J Med. 2022;387:205-216. NEJM
- Aronne LJ, et al. Tirzepatide versus Semaglutide for the Treatment of Obesity (SURMOUNT-5). N Engl J Med. 2025. NEJM
- Eli Lilly. Zepbound (tirzepatide) approved and available in Canada, 2025. Lilly
- Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP-1). N Engl J Med. 2021;384:989-1002. NEJM
This article summarizes published research and regulatory information for information only and is not medical advice. TrueLabs research compounds are sold for in vitro and laboratory research use only and are not intended for human or veterinary use.