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Guide 2 of 9 · Stage: Understand

What do GLP-1 medicines do?

How semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) work in your body, what they can and can't do, the risks, and what Health Canada has approved.

GLP Guidebook teamUpdated 12 Oct 202613 min read36 sourcesWritten from published sources
The short answer

GLP-1 stands for glucagon-like peptide-1, a hormone your gut makes after you eat. GLP-1 medicines copy it. They help you feel full sooner, slow your stomach and help control blood sugar. Most weight loss comes from eating less. Common side effects are feeling sick and diarrhea, and weight usually returns after stopping. Talk to a doctor before starting, stopping or changing one.

Key facts

What they are
Medicines that copy GLP-1, a gut hormone1
Main ones in Canada
  • Semaglutide: Ozempic, Wegovy, Rybelsus, and generic versions of Ozempic since May 20262,3
  • Tirzepatide: Mounjaro, Zepbound4,5
  • Liraglutide: Saxenda, Victoza2
  • Dulaglutide: Trulicity2
Approved in Canada for
  • Type 2 diabetes: Ozempic and its generics, Rybelsus, Mounjaro, Victoza, Trulicity
  • Weight management: Wegovy, Zepbound, Saxenda, and Sevmia (a generic of Wegovy, approved but not yet on sale as of 12 Oct 2026)2,6
How weight loss happens
Mostly by eating less. They don't speed up the calories you burn at rest.9
Main risks
Feeling sick, diarrhea and vomiting are common. Rarer serious risks include pancreatitis and gallbladder problems. See the risks, in brief10,7
Prescription
Yes, all of them are prescription drugs in Canada. A family doctor or nurse practitioner can prescribe them; you don't need a specialist.2,8
On this page
  1. What does GLP-1 mean?
  2. What do the medicines do in your body?
  3. Why do people lose weight on them?
  4. Do the results hold for people of different ethnic backgrounds?
  5. How is this different from metformin and other diabetes pills?
  6. Who these are for, and who they're not for
  7. Which GLP-1 medicines are approved in Canada?
  8. Is Ozempic the same as Wegovy?
  9. How long do they take to work, and how long do they last?
  10. Do they do anything besides weight and sugar?
  11. What these medicines do not do
  12. Are these medicines new?
  13. Questions people ask

What does GLP-1 mean?

GLP-1 is short for glucagon-like peptide-1. It's a hormone your gut releases after you eat, telling your body that food has arrived.

It's made mostly in the lower part of your small intestine and in your large intestine.1 It sends signals to your brain, stomach and pancreas (an organ behind your stomach that makes hormones).

Your body's own GLP-1 doesn't last long. An enzyme (a protein that breaks other things down) clears it in about 1 to 2 minutes.1 So its natural effect is small and short.

What do GLP-1 medicines do in your body?

A GLP-1 medicine is a lab-made version of GLP-1, changed so your body can't break it down quickly. Your own GLP-1 is gone in 1 to 2 minutes. Semaglutide, the medicine in Ozempic and Wegovy, keeps working for about a week.1,10

So the "food has arrived" message that your gut normally sends for a few minutes after a meal is sent all day, every day, and more strongly.

Your own GLP-1Made by your gut after you eatGone in 1 to 2 minutes
A GLP-1 medicineA weekly injection or a daily tabletKeeps sending the message all week

The message reaches four parts of your body

BrainYou feel less hungryThe part of your brain that controls appetite is told you've eaten, so you want less food and feel full sooner.Helps with weight
StomachYou stay full for longerYour stomach empties more slowly, so a meal stays with you longer before you feel hungry again.Helps with weight
PancreasSugar leaves your blood fasterYour pancreas releases more insulin, the hormone that moves sugar out of your blood. It does this only when your sugar is high.Helps with blood sugar
LiverLess extra sugar is addedYour liver stores sugar and releases it when a hormone called glucagon tells it to. The medicine lowers glucagon when your sugar is high, so the liver adds less.Helps with blood sugar

Simplified. Based on a scientific review of GLP-1 and the US Wegovy label.1,10

In short: the brain and stomach effects are why people eat less and lose weight. The pancreas and liver effects are why these medicines lower blood sugar in type 2 diabetes.

Because the pancreas and liver effects only switch on when sugar is high, the medicine mostly leaves normal sugar levels alone. Sugar can still drop too low if it's taken with insulin or certain other diabetes medicines.10

Why do people lose weight on them?

Mainly because they eat less. In a small study, semaglutide did not change the calories people burned at rest.9

That study gave 30 people semaglutide 1 mg or a dummy injection (one with no medicine in it) for 12 weeks each. On semaglutide, they ate 24% less across a full day of eat-as-much-as-you-like meals.9 They also reported less hunger and fewer food cravings.9

The two biggest weight trials are called STEP 1 (semaglutide, made by Novo Nordisk) and SURMOUNT-1 (tirzepatide, made by Eli Lilly). Each one worked the same way:

  • People were split at random into two groups. One group got the medicine. The other got a dummy injection.
  • Both groups got the same diet and exercise advice, and nobody knew which injection they were on.
  • So the gap between the two groups is what the medicine itself added.14,15

Average weight lost. Kilograms are for someone who starts at 90 kg (198 lb).

STEP 1Semaglutide 2.4 mg (Wegovy), weekly

1,961 adults with obesity or overweight, without diabetes. 68 weeks.14

Semaglutide14.9%about 13 kg
Dummy injection2.4%about 2 kg
SURMOUNT-1Tirzepatide 15 mg (the Zepbound dose), weekly

2,539 adults with obesity or overweight, without diabetes. 72 weeks.15

Tirzepatide20.9%about 19 kg
Dummy injection3.1%about 3 kg

Which works better? You can't tell by comparing the two cards above, because they were different trials with different people. One trial, SURMOUNT-5, tested the two medicines against each other in the same group of people. Each person took the highest dose they could manage. It was paid for by Eli Lilly, the maker of tirzepatide.16 Tirzepatide also acts on a second gut hormone, called GIP (glucose-dependent insulinotropic polypeptide), which may help explain the difference.5

SURMOUNT-5Tirzepatide vs semaglutide, head to head

751 adults with obesity, without diabetes. 72 weeks.16

Tirzepatide20.2%about 18 kg
Semaglutide13.7%about 12 kg

People with type 2 diabetes usually lose less. STEP 2 ran the same test in people with diabetes: about 9 kg lost instead of 13 kg, on the same dose.14,17

STEP 2Semaglutide 2.4 mg, people with diabetes

1,210 adults with overweight or obesity and type 2 diabetes. 68 weeks.17

Semaglutide9.6%about 9 kg
Dummy injection3.4%about 3 kg

All of these are averages. Some people lose much more, and some lose very little.14 Ozempic's doses for diabetes (up to 2 mg) are lower than Wegovy's 2.4 mg, so these weight figures aren't Ozempic's.3,6

RisksThe risks, in brief
44 in 100felt sick on Wegovy, against 16 in 100 on a dummy injection (US label)10
24 in 100vomited on Wegovy, against 6 in 100 on a dummy injection (US label)10
  • Pancreatitis (a swollen, painful pancreas) has been seen. Severe stomach pain that may spread to the back is a warning sign.10,7
  • Gallbladder problems, such as gallstones, are more common.10,7
  • Dehydration from vomiting or diarrhea can hurt the kidneys.10
  • Thyroid warning. Semaglutide and tirzepatide caused thyroid tumours in rodents. The Canadian guideline lists a personal or family history of medullary thyroid cancer, or MEN 2 (a rare inherited condition that causes gland tumours), as a reason not to use them.7,10
  • Not in pregnancy. The makers recommend stopping semaglutide at least 2 months, and tirzepatide at least 1 month, before a planned pregnancy.7
  • Before surgery or sedation: because they slow the stomach, rare reports raise concern about food entering the lungs under general anaesthesia. Tell your care team you take one.7
  • Report side effects to Health Canada's Canada Vigilance Program, online through MedEffect Canada or by phone at 1-866-234-2345.18
Full detail in Guide 5: Side effects and risks →
Weight usually comes back when you stop. In a STEP 1 follow-up, people had lost 17.3% on semaglutide. A year after stopping, they had regained about two-thirds of it, on average.19 The Canadian guideline says stopping can lead to weight regain and the loss of health benefits.7 More in Guide 9: Stopping

Not all the weight lost is fat. A scan study inside STEP 1 looked at 140 people. On semaglutide, fat fell by about 19% and lean mass by about 10%.20 In other words, people lost about a fifth of their fat and about a tenth of their lean mass. Lean mass means everything that isn't fat. It includes muscle, but also organs, bone and water.21 Guide 8 covers eating and exercise on these medicines.

Do the results hold for people of different ethnic backgrounds?

Trials in East Asian people show similar weight loss. None of the trials on this page was run specifically in South Asian or Black people.

  • Japan and South Korea (401 people, STEP 6): 13.2% of body weight lost on semaglutide 2.4 mg over 68 weeks, against 2.1% on a dummy injection.22
  • China (210 people, SURMOUNT-CN): 13.6% of body weight lost on tirzepatide 10 mg and 17.5% on 15 mg over 52 weeks, against 2.3% on a dummy injection.23
  • Japan (225 people analysed, SURMOUNT-J): people on tirzepatide lost about 16% (10 mg) and 21% (15 mg) more of their body weight than people on a dummy injection, over 72 weeks.24

The Canadian guideline notes that people from non-white backgrounds were under-represented in the trials, and that the trials used BMI cut-offs that weren't ethnicity-specific. It asks doctors to use ethnicity-specific BMI and waist measures when deciding whether to start a medicine.7 Guide 1 explains the lower thresholds for South, Southeast and East Asian adults.

How is this different from metformin and other diabetes pills?

GLP-1 medicines lower blood sugar and also reduce appetite. In Canada they are usually added to metformin, not used first.25

Metformin mainly stops your liver releasing too much sugar and helps your body use insulin better. It doesn't make your pancreas release more insulin.26 Diabetes Canada says metformin should usually be chosen before other medicines, because of its low risk of low blood sugar and weight gain. For people with heart or blood-vessel disease, it recommends a GLP-1 medicine or an SGLT2 inhibitor (a tablet that makes you pass extra sugar in your urine) with proven heart or kidney benefit.25 Public drug plans follow the same order: Ontario's plan, for example, covers semaglutide for type 2 diabetes when metformin hasn't controlled blood sugar enough.27

HbA1c (often written A1C in Canada) is a blood test showing your average sugar over the past few months. In a 30-week trial of Ozempic on its own, A1C started around 8.1%. It fell by 1.4 to 1.6 percentage points, against 0.1 on a dummy injection.28 That means from about 8.1% to about 6.5–6.7%.

Watch for low blood sugar if you take other diabetes medicines. The risk goes up when GLP-1s are combined with insulin or sulfonylureas.10,28 Sulfonylureas, such as gliclazide, carry a higher risk of low sugar on their own than GLP-1 medicines do.25 Doctors may lower the dose of these when starting a GLP-1.10

The type 2 diabetes path covers this in more detail: I have type 2 diabetes.

Who these are for, and who they're not for

In Canada, each brand is approved by Health Canada for set uses: type 2 diabetes, weight management, or other conditions. Whether one suits you is a decision for you and a doctor.

  • Type 2 diabetes: Ozempic and its generic versions, Rybelsus, Mounjaro, Victoza and Trulicity.2,3,4
  • Weight management: Wegovy, Zepbound and Saxenda. Sevmia, a generic version of Wegovy, was approved in June 2026 but was not yet on sale as of 12 Oct 2026.6,5,2,11
  • Teenagers: Wegovy and Saxenda are approved from age 12 for young people with obesity. For Wegovy they must weigh over 60 kg (132 lb).6,2
  • Heart protection: Wegovy is approved to lower the risk of a non-fatal heart attack in adults with established heart or blood-vessel disease and a BMI of 27 or more.6
  • Sleep apnoea: since June 2026, Zepbound is approved for moderate to severe obstructive sleep apnoea (breathing that stops and starts during sleep) in adults with obesity.5
  • Fatty liver with scarring (MASH): Wegovy's Canadian label added this in October 2026, under a conditional approval that depends on further studies confirming the benefit.6

The label rules for weight are a BMI of 30 or more, or 27 to 30 with at least one weight-related condition such as high blood pressure. Saxenda's label adds that a previous weight-management attempt has not worked.6,5,2 The Canadian guideline asks doctors to adjust these numbers with ethnicity-specific BMI and waist measures.7 These are points to start a conversation with a doctor, not a sign that you qualify.

Not tested in type 1 diabetes. The US Wegovy label says its use in people with type 1 diabetes has not been studied.10 (A label is the official prescribing document for a medicine. In Canada it's called the product monograph.)

Tirzepatide and the contraceptive pill. Tirzepatide (Mounjaro, Zepbound) can make the pill work less well. The Canadian guideline says to switch to a non-pill method, or add a barrier method such as condoms, for 4 weeks after starting and for 4 weeks after each dose increase.7

They're not for losing a few kilos before a holiday or event. The Canadian guideline is clear that these are long-term treatments for obesity, a chronic disease, and weight tends to come back after stopping.7,19 If that's you, read I want to lose a few kilos.

Who shouldn't take them, and what to ask, is in Guide 4: Should I consider a GLP-1?

Which GLP-1 medicines are approved in Canada?

Every GLP-1 medicine has two kinds of name: the name of the medicine itself, and the brand names it's sold under. Knowing the difference stops a lot of confusion.

The medicineWhat actually works in your bodyThe same chemical, whoever makes it. Doctors and labels use this name.
e.g. Acetaminophen (called paracetamol in many countries)
The brandThe name on the boxChosen by the company selling it. One medicine can have many brands.
e.g. Tylenol, Tempra

GLP-1 medicines work the same way. Semaglutide is the medicine, and Ozempic, Wegovy and Rybelsus are brands of it. Two brands of the same medicine can still differ in dose, in whether they're an injection or a tablet, and in what they're approved for.

A generic is a copy made by another company once patents and data protection end. In April 2026, Canada became the first G7 country to approve a generic semaglutide.12 Every product sold in Canada has an 8-digit Drug Identification Number (DIN) on the label, which you can look up in Health Canada's Drug Product Database.13

The GLP-1 medicines approved in Canada, and their brands (as of 12 Oct 2026)

MedicineSemaglutide →Weekly injection, or a daily tablet
  • OzempicNovo Nordisk · weekly injectionFor type 2 diabetes, including heart and kidney protection3
  • WegovyNovo Nordisk · weekly injectionFor weight, heart attack risk and MASH6
  • RybelsusNovo Nordisk · daily tabletFor type 2 diabetes2
  • Generic versions of OzempicOn sale since May 2026: Dr. Reddy's Semaglutide Injection and Apo-Semaglutide (Apotex). Approved, not yet on sale: Aspen and Sandoz versions.For type 2 diabetes2,11
  • SevmiaApotex · weekly injection, 1 mg pen only. Approved June 2026, not yet on sale.Generic of Wegovy: for weight11
MedicineTirzepatide →Weekly injection
  • MounjaroEli Lilly · weekly injection (KwikPen)For type 2 diabetes only4
  • ZepboundEli Lilly · weekly injection (4-dose KwikPen)For weight, and sleep apnoea in adults with obesity5
MedicineDulaglutide →Weekly injection
  • TrulicityEli Lilly · weekly injectionFor type 2 diabetes2
MedicineLiraglutide →Daily injection
  • SaxendaNovo Nordisk · daily injectionFor weight management2
  • VictozaNovo Nordisk · daily injectionFor type 2 diabetes2

Names only, not a recommendation. Not approved in Canada as of 12 Oct 2026: orforglipron, retatrutide, CagriSema and the higher-dose Wegovy tablet.2 Doses, prices and how to get them are in Guide 6.

Canada note: fakes and "research peptides". Health Canada warns about fake and unauthorized Ozempic and Mounjaro sold in stores and online, some misusing official logos. It says to buy prescription drugs only from a licensed pharmacy and to check the DIN.13 In August 2025 it warned that injectable "peptides", including tirzepatide and retatrutide, sold online by one company were illegal in Canada.29 Health Canada also does not allow routine compounding (mixing up your own version) of semaglutide.30 Guide 6 covers safe ways to get them.

Is Ozempic the same as Wegovy?

Same medicine, different brand. Both are semaglutide, made by Novo Nordisk. They are approved for different uses and go up to different doses.

  • Ozempic is approved in Canada for type 2 diabetes, including lowering heart and kidney risk in some people with diabetes. Its highest dose is 2 mg a week.3
  • Wegovy is approved for weight management. Its usual full dose is 2.4 mg a week.6

Using a medicine for something it isn't approved for is called "off-label". Using Ozempic for weight loss is off-label in Canada, and so is using Mounjaro for weight loss.3,4 A doctor may still prescribe a medicine off-label on their own judgment, and the Canadian obesity guideline says off-label prescribing can be in line with medical ethics.7 Drug makers can't advertise a prescription medicine to the public in Canada beyond its name, price and quantity.36 Plans that cover Ozempic for diabetes won't usually cover it for weight.27

Mounjaro and Zepbound are a different medicine: tirzepatide, made by Eli Lilly. Mounjaro is the diabetes brand and Zepbound the weight brand. The Zepbound label says not to use it together with Mounjaro or any GLP-1 medicine.4,5

How long do they take to work, and how long do they last?

You start on a low dose and go up slowly, usually every 4 weeks. Weight loss builds over many months.6,14

In trials, stomach side effects happened mostly while the dose was still going up.15,16

Your prescriber sets your dose. This is the usual Wegovy schedule, shown so you know what to expect.6,14
  1. Weeks 1–40.25 mg once a week
  2. Weeks 5–80.5 mg
  3. Weeks 9–121 mg
  4. Weeks 13–161.7 mg
  5. Week 17 on2.4 mg, the usual full dose

In STEP 1, average weight kept falling until about week 60, then levelled off.14 The Canadian guideline notes that regulators have traditionally advised stopping if you haven't lost 5% after three months on a full dose, but says real health gains can come whatever the amount of weight lost.7 Guide 9 covers when to review.

Why once a week, and how long it stays in your body

Your body clears semaglutide slowly. About half of each dose is gone after a week, so one injection a week keeps enough in your blood.1,10

The same slow clearing means the medicine doesn't leave your body the day you stop taking it. After your last dose, it takes about 5 weeks to leave your blood.28

This matters most if you're planning a pregnancy. The maker recommends stopping semaglutide at least 2 months before a planned pregnancy, to give it time to leave your body.7

Do they do anything besides weight and sugar?

In one large trial, semaglutide lowered the combined risk of heart attack, stroke and heart-related death. Most of that came from fewer heart attacks.

The SELECT trial followed 17,604 people for about 3 years.31 All were 45 or older, had overweight or obesity, and no diabetes. All already had heart or blood-vessel disease: a past heart attack, a past stroke, or narrowed leg arteries.10

6.5 in 100had a heart attack, stroke or heart-related death on semaglutide31
8.0 in 100did on a dummy injection31

That's about 1 fewer event for every 67 people treated. Heart attacks fell from 3.8 to 2.8 in 100. Strokes went from 2.0 to 1.8 in 100, a difference too small to be sure of.10

In Canada, Wegovy's label covers lowering the risk of a non-fatal heart attack in adults with established heart or blood-vessel disease and a BMI of 27 or more.6 In July 2025, Canada's Drug Agency recommended that public plans pay for Wegovy for this group, with conditions. Price talks then ended without agreement in December 2025, so no public plan covers it.32,33 It applies to people who already have that disease, not to everyone.

Other approvals in Canada: Ozempic for lowering kidney and heart risk in people with type 2 diabetes and kidney disease, Zepbound for sleep apnoea in adults with obesity, and Wegovy for fatty liver with scarring (MASH).3,5,6

What these medicines do not do

  • They're not a cure. On average, people regained two-thirds of the lost weight within a year of stopping.19
  • They don't burn fat. They work by cutting how much you eat, not by speeding up your body.9
  • They're not a short course. The Canadian guideline says to use them long term, when they work.7
  • They don't replace food and activity changes. Every recommendation in the Canadian guideline pairs the medicine with health behaviour changes.7
  • Compounded or "research" versions aren't the same thing. The Canadian guideline recommends against compounded medicines and any not approved in Canada for weight loss.7

Are these medicines new?

No. The first GLP-1 medicine was approved in the US in 2005, and Victoza has been sold in Canada since 2010. What's new is how strong and long-lasting they've become.34,2

The first one, exenatide, came from a substance found in the saliva of a lizard, the Gila monster.1 Later versions were changed to last longer in the body. Half of each semaglutide dose is cleared in about a week.1,10

  1. 2005Exenatide (Byetta) approved in the US34
  2. 2010Victoza (liraglutide) on sale in Canada for diabetes2
  3. 2015Saxenda on sale in Canada for weight2
  4. Jan 2018Ozempic approved by Health Canada35
  5. Nov 2021Wegovy approved for weight (pens on sale from 2024)32,2
  6. Nov 2022Mounjaro approved for type 2 diabetes35
  7. May 2025Zepbound approved for weight5
  8. Apr 2026First generic semaglutide approved, a first in the G712
  9. Jun 2026Zepbound approved for sleep apnoea; Sevmia (generic Wegovy) approved5,11
  10. Oct 2026Wegovy label adds MASH (conditional approval)6

Questions people ask

What does GLP-1 stand for?

Glucagon-like peptide-1. It's a hormone your gut makes after you eat.1

Is Ozempic approved for weight loss in Canada?

No. Health Canada approved Ozempic for type 2 diabetes.3 Wegovy is the same medicine, semaglutide, approved for weight management.6 Using Ozempic for weight is off-label. See Ozempic vs Wegovy.

Is Zepbound the same as Mounjaro?

Same medicine, tirzepatide, made by Eli Lilly. In Canada, Mounjaro is approved for type 2 diabetes and Zepbound for weight management and sleep apnoea in adults with obesity.4,5 More in Zepbound vs Mounjaro in Canada.

Is a GLP-1 medicine the same as insulin?

No. Insulin lowers blood sugar directly. GLP-1 medicines help your body release its own insulin when sugar is high, and they also reduce appetite.1

Why is it an injection once a week?

Half of each semaglutide dose is cleared in about a week, which is why it's taken once a week.1,10 Your own GLP-1 lasts 1 to 2 minutes.1 Rybelsus is a daily semaglutide tablet for type 2 diabetes.2

Can food, supplements or 'research peptides' do the same thing?

Eating does release your own GLP-1, but your body clears it within minutes.1 Health Canada warns that "research peptide" tirzepatide and retatrutide sold online are illegal in Canada, and says to buy prescription drugs only from a licensed pharmacy.29,13

Do I need a prescription in Canada?

Yes. All GLP-1 medicines are prescription drugs in Canada.2 A family doctor or nurse practitioner can prescribe them; you don't need a specialist.8 Guide 6 explains the routes and who pays.

Before you move on

  • GLP-1 medicines mostly work by making you eat less.
  • Ozempic and Wegovy are both semaglutide; Mounjaro and Zepbound are both tirzepatide.
  • In Canada, only Wegovy, Zepbound, Saxenda and Sevmia are approved for weight.
  • Stomach side effects are common, and there are rarer serious risks.
  • They're long-term. Weight usually returns after stopping.
Side effects and risksShould I consider a GLP-1?I have type 2 diabetes
Was this guide easy to understand?

Sources

  1. Müller TD et al. Glucagon-like peptide 1 (GLP-1). Molecular Metabolism, 2019;30:72–130. doi:10.1016/j.molmet.2019.09.010 · PMID 31767182
  2. Health Canada. Drug Product Database: product records, status and schedule for semaglutide, tirzepatide, liraglutide and dulaglutide products (including Rybelsus, Saxenda, Victoza, Trulicity, generic semaglutide; "Prescription" schedule; first-marketed dates). Searched 12 October 2026. health-products.canada.ca
  3. Novo Nordisk Canada. Ozempic (semaglutide injection) Product Monograph, 13 July 2026 (indications, doses). Health Canada Drug Product Database
  4. Eli Lilly Canada. Mounjaro (tirzepatide injection) Product Monograph, 23 June 2026 (indications: adults and children 10 to under 18 with type 2 diabetes). Health Canada Drug Product Database
  5. Eli Lilly Canada. Zepbound (tirzepatide injection) Product Monograph, 11 June 2026 (weight management; obstructive sleep apnoea; first authorized 13 May 2025; not to be used with Mounjaro or other GLP-1 medicines). Health Canada Drug Product Database
  6. Novo Nordisk Canada. Wegovy (semaglutide injection) Product Monograph, revised 2 October 2026 (weight management, adolescents over 60 kg, non-fatal heart attack risk, MASH under the NOC/c policy, dose schedule). Health Canada Drug Product Database
  7. Pedersen SD, Manjoo P, Dash S, Jain A, Pearce N, Poddar M. Canadian Adult Obesity Clinical Practice Guideline: Pharmacotherapy for Obesity Management in Adults, 2025 update. Obesity Canada, Version 3, 11 August 2025 (recommendations 1–13; side-effect table; pregnancy, contraception and anaesthesia notes; off-label prescribing). obesitycanada.ca (PDF)
  8. Canada's Drug Agency (CDA-AMC). Semaglutide (Wegovy) reimbursement review SR0841, clinician input: "any health care provider with experience managing obesity could prescribe semaglutide … not … restricted to specialists alone". canjhealthtechnol.ca
  9. Blundell J et al. Effects of once-weekly semaglutide on appetite, energy intake, control of eating, food preference and body weight in subjects with obesity. Diabetes, Obesity and Metabolism, 2017;19:1242–51. doi:10.1111/dom.12932
  10. Novo Nordisk. Wegovy (semaglutide) prescribing information, US label (FDA), revised June 2026. Not the Canadian label. DailyMed
  11. Generic semaglutide in Canada: Health Canada Drug Product Database records and product monographs (Dr. Reddy's authorized 28 Apr 2026, marketed 6 May 2026; Apo-Semaglutide authorized 1 May 2026, marketed 14 May 2026; Sevmia authorized 29 Jun 2026, status "Approved"; Aspen 17 Jul and 25 Aug 2026; Sandoz 16 Sep 2026, "Approved"); Apotex press release on Sevmia, 30 June 2026. Checked 12 October 2026. health-products.canada.ca
  12. Health Canada. Canada becomes the first G7 country to approve a generic version of semaglutide. News release, 28 April 2026. canada.ca
  13. Health Canada. Thinking about buying GLP-1 drugs like Ozempic or Mounjaro? Beware of fake or unauthorized products (advisory RA-81518), updated 21 January 2026. recalls-rappels.canada.ca
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  15. Jastreboff AM et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). NEJM, 2022;387:205–16. doi:10.1056/NEJMoa2206038
  16. Aronne LJ et al. Tirzepatide as compared with semaglutide for the treatment of obesity (SURMOUNT-5). NEJM, 2025;393:26–36. Paid for by Eli Lilly, the maker of tirzepatide. doi:10.1056/NEJMoa2416394
  17. Davies M et al. Semaglutide 2·4 mg once a week in adults with overweight or obesity, and type 2 diabetes (STEP 2). Lancet, 2021;397:971–84. doi:10.1016/S0140-6736(21)00213-0
  18. Health Canada. Adverse reaction and medical device problem reporting (Canada Vigilance Program, MedEffect Canada; phone 1-866-234-2345). canada.ca
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  20. Wilding JPH et al. Impact of semaglutide on body composition in adults with overweight or obesity: exploratory analysis of the STEP 1 study. Conference abstract, 2021. 140 people in a body-scan substudy of STEP 1. Abstract PDF
  21. Neeland IJ, Linge J, Birkenfeld AL. Changes in lean body mass with GLP-1-based therapies and mitigation strategies. Diabetes, Obesity and Metabolism, 2024;26 Suppl 4:16–27. doi:10.1111/dom.15728
  22. Kadowaki T et al. Semaglutide once a week in adults with overweight or obesity, with or without type 2 diabetes, in an east Asian population (STEP 6). Lancet Diabetes & Endocrinology, 2022;10:193–206. doi:10.1016/S2213-8587(22)00008-0
  23. Zhao L et al. Tirzepatide for weight reduction in Chinese adults with obesity (SURMOUNT-CN). JAMA, 2024;332:551–60. doi:10.1001/jama.2024.9217
  24. Kadowaki T et al. Efficacy and safety of once-weekly tirzepatide in Japanese patients with obesity disease (SURMOUNT-J). Lancet Diabetes & Endocrinology, 2025;13:384–96. doi:10.1016/S2213-8587(24)00377-2
  25. Lipscombe L et al.; Diabetes Canada Clinical Practice Guidelines Expert Committee. Pharmacologic glycemic management of type 2 diabetes in adults: 2020 update. Can J Diabetes 2020;44:575–91 ("Metformin should usually be selected before other agents"; GLP-1 RA or SGLT2i with proven benefit in heart and blood-vessel disease; lower hypoglycemia risk than sulfonylureas and insulin). diabetes.ca
  26. Metformin hydrochloride prescribing information, US label (FDA), via DailyMed, September 2026. DailyMed
  27. Ontario Ministry of Health. Ontario Drug Benefit Formulary: semaglutide and Rybelsus listed as Limited Use for type 2 diabetes (criteria: inadequate control on, or intolerance of, metformin). Checked 12 October 2026. formulary.health.gov.on.ca
  28. Novo Nordisk. Ozempic (semaglutide) prescribing information, US label (FDA), June 2026. Not the Canadian label. DailyMed
  29. Health Canada. Unauthorized injectable peptide drugs seized and sold in Canada (advisory), 1 August 2025. recalls-rappels.canada.ca
  30. Alberta College of Pharmacy. Unauthorized compounding of semaglutide-containing products is not permitted (citing Health Canada policy POL-0051). 10 June 2025. abpharmacy.ca
  31. Lincoff AM et al. Semaglutide and cardiovascular outcomes in obesity without diabetes (SELECT). NEJM, 2023;389:2221–32. doi:10.1056/NEJMoa2307563
  32. Canada's Drug Agency (CDA-AMC). Semaglutide (Wegovy) reimbursement recommendation SR0841, July 2025: "Reimburse with conditions" for adults with BMI 27 or more and established cardiovascular disease; lists the NOC date of 23 November 2021. canjhealthtechnol.ca
  33. BC PharmaCare. Drug coverage decision: semaglutide (Wegovy), 18 December 2025 ("Non-benefit"; pCPA negotiations concluded without agreement on 1 December 2025). gov.bc.ca (PDF)
  34. US Food and Drug Administration. Byetta (exenatide) NDA 021773, approved 28 April 2005. 2005 label (FDA)
  35. Health Canada. Register of Innovative Drugs, 24 January 2025 edition (Ozempic notice of compliance 4 January 2018; Mounjaro 24 November 2022). canada.ca (PDF)
  36. Food and Drug Regulations, C.R.C., c. 870, section C.01.044 (advertising prescription drugs to the general public: brand name, proper name, common name, price and quantity only). Current to 21 September 2026. laws-lois.justice.gc.ca

Last checked 12 Oct 2026 · Next review due Jan 2027 · Report an error

How this guide was made. Written by the GLP Guidebook team from the sources above: published trials, Canadian product monographs and US labels, Health Canada records, and Canadian obesity and diabetes guidelines. Where we cite a US label, we say so. It's general information, not medical advice. Talk to your family doctor, nurse practitioner or pharmacist before starting, stopping or changing any medicine. In an emergency, call 911. For health advice that isn't an emergency, call 811 in most provinces and territories (Info-Santé 811 in Quebec). Report suspected side effects to the Canada Vigilance Program. How we write