Zepbound Or Wegovy: Which Is Better?

Wegovy versus Zepbound: Which is right for you?

	Wegovy	Zepbound
Active ingredient	Semaglutide	Tirzepatide
How it works	Mimics GLP-1 hormone to induce satiety, slow digestion and reduce hunger.	Mimics GLP-1 and GIP hormones to increase feelings of fullness, slow digestion and reduce hunger.
Administration	Weekly injections	Weekly injections
Doses	0.25mg, 0.5mg, 1mg, 1.7mg, and 2.4mg.	2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.
Effectiveness	Mean weight loss achieved by month 12: 8.3%.	Mean weight loss achieved by month 12: 15.3%.
Cost per pen (without insurance)	$400 - $500	$400 - $530
Cost over a year	Approximately $4,800 - $6,000	Approximately $4,800 - $6,360
Common side effects	Headache; Nausea; Vomiting; Diarrhea; Constipation; Stomach pain; Feeling weak; Changes in vision, especially for people with diabetes	Hypoglycaemia; Nausea; Vomiting; Diarrhea; Stomach pain; Constipation;

Summary:

Zepbound achieved approximately 15% weight loss by month 12, compared to 8% with Wegovy.
Annual cash costs for both drugs are similar, ranging from approximately $4,800 to over $6,000, depending on the medication and the pharmacy.
Both drugs cause side effects like nausea and vomiting.
Zepbound reduces oral contraceptive effectiveness, while Wegovy is safe with all contraception types.

How do Wegovy and Zepbound work?

Wegovy and Zepbound are two weight loss injections in the category of drugs called GLP-1 receptor agonists. Wegovy contains semaglutide, which targets the GLP-1 receptors, while Zepbound contains tirzepatide, which targets GLP-1 and GIP receptors.

Mode of action

Semaglutide mimics GLP-1, a hormone that's naturally released after meals. It promotes feelings of fullness, slows down digestion and reduces your cravings. This regulates your appetite and curbs feelings of hunger.

Tirzepatide mimics GLP-1 and GIP, two hormones that are released after meals. Like semaglutide, it induces satiety, slows digestion and reduces food cravings. The addition of GIP enhances the weight loss effects, making tirzepatide more effective than semaglutide for some users.

Both treatments target GLP-1 receptors, with Zepbound also targeting GIP receptors. As a result, both increase feelings of fullness, slow digestion and reduce hunger.

How they’re administered

Wegovy and Zepbound are injected weekly under the skin in your stomach, thigh or upper arm, on the same day around the same time. The dose increases every four weeks until you reach the maintenance dose.

Wegovy is available in five doses: 0.25mg, 0.5mg, 1mg, 1.7mg, and 2.4mg (maintenance dose).
Zepbound is available in six doses: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg (maintenance dose).

Some people might choose to remain on a lower dose for longer than four weeks because of the side effects or higher costs that come with higher doses. Staying at the lower dose until the side effects become manageable can make the weight loss journey more comfortable. Additionally, as the dose increases, the cost of one pen also increases, so you might decide to wait until you’re financially stable before moving up. While remaining on a lower dose might slow your weight loss progress, it can still deliver results.

For Zepbound, clinicians might recommend a 10mg maintenance dose instead of the typical 15mg. The difference in weight loss between the two doses is minimal, but the 10mg dose carries a lower risk of side effects and is significantly cheaper.

Wegovy is available in 5 doses and Zepbound is available in 6 doses. Both are injected weekly, with the dose increasing every four weeks until you reach the maintenance dose.

Which is the most effective for weight loss?

Multiple studies have shown the effectiveness of both Wegovy and Zepbound for weight loss. Below is a summary of their results.

Effectiveness of Wegovy

In one study with 1961 patients taking 2.4mg semaglutide, the mean weight loss achieved was 14.1% by week 68, compared to 2.4% in the placebo group. The results found:

86.4% of participants achieved 5% or more weight loss
69.1% of participants achieved 10% or more weight loss
50.5% of participants achieved 15% or more weight loss

These findings were similar to another study with 175 patients with overweight or obesity. The mean weight loss achieved by week 26 was 10.9% (around 12.3kg or 27 lbs). The findings included:

87.3% achieved a weight loss of 5%
54.9% achieved a weight loss of 10%,
23.5% achieved a weight loss of 15%
7.8% achieved a weight loss of 20% or more.

The study also highlighted that higher doses (1.7mg and 2.4mg) resulted in more weight loss than the lower doses (0.25mg, 0.5mg, 1mg). Participants on the higher dose achieved a mean weight loss of 12.1% compared to 9.2% for those receiving lower doses. Other benefits included better cardiovascular health, improvement in blood sugar and reduced risk of kidney disease.

However, stopping treatment with semaglutide often led to weight gain. In a study, 327 patients lost an average of 17.3% of their body weight over 68 weeks, but by week 120, they regained an average of 11.6% of that weight. This shows the importance of continued treatment and adhering to lifestyle changes.

Effectiveness of Zepbound

In a study with 2539 participants, the mean weight loss achieved by week 72 using Zepbound was:

15.0% with 5mg
19.5% with 10mg
20.9% with 15mg
3.1% with placebo

Aside from the weight loss benefits, participants using tirzepatide showed improvements in blood pressure, insulin sensitivity, and cholesterol levels. Additionally, by week 72, most pre-diabetic participants (95%) had normal blood sugar levels.

As previously mentioned, the clinician may recommend staying on a 10mg maintenance dose instead of 15mg due to similar effectiveness and cost benefits. The results prove there’s little difference in weight loss achieved with 10mg compared to 15mg.

Similar to semaglutide, stopping tirzepatide commonly led to weight regain. A study of 670 participants who achieved an average weight reduction of 20.9% by week 36. Half of these individuals continued treatment, while the other half received a placebo. Upon follow-up at week 88, patients who continued taking tirzepatide lost an additional 5.5%, whereas those receiving the placebo experienced a 14% weight gain.

How does Wegovy compare with Zepbound?

A comparative study found tirzepatide (Zepbound) to be more effective than semaglutide (Wegovy) in a trial consisting of 41,222 participants. Of these, 32,029 were treated with semaglutide, while 9,193 received tirzepatide. The mean weight loss achieved with each treatment was as follows:

After 3 months: 5.9% for tirzepatide compared to 3.6% for semaglutide.
After 6 months: 10.1% for tirzepatide compared to 5.8% for semaglutide.
After 12 months: 15.3% for tirzepatide compared to 8.3% for semaglutide.

The differences in weight loss could be because of tirzepatide's ability to target GLP-1 and GIP receptors, compared to semaglutide which only targets GLP-1 receptors.

Both are effective at helping you lose weight, but Zepbound is more effective than Wegovy.

Which has the least side effects?

Wegovy and Zepbound carry the risk of side effects, with gastrointestinal side effects being the most common due to GLP-1 receptor agonists’ effect on stomach digestion. The most common side effects reported include:

Nausea
Vomiting
Diarrhea
Fatigue
Abdominal pain

While you may experience other side effects, these are the most common ones. For the full list of side effects, always check the patient information leaflet.

To reduce the risk of side effects, consider gradually increasing your dose to allow your body to adjust to the treatment. Alternatively, you can remain on a lower dose until the side effects become manageable. It may also help to avoid fatty or greasy foods and stick to simple, bland options to reduce the risk of nausea and vomiting. Eating small meals more frequently can also aid digestion and relieve symptoms like nausea and abdominal pain.

If the side effects become unmanageable, switching to another weight loss treatment might help. Everyone reacts differently to medications, so try finding one that works best for you. If you’re unsure what to choose, our clinicians are available to help.

Both drugs carry the risk of getting side effects with nausea, vomiting, diarrhea and stomach pain being the most common. But there are things you can do to make them manageable.

Which is more cost-effective?

The cost information below represents the cash price without any public or private insurance coverage. Actual out-of-pocket costs will vary significantly based on your insurance plan.

Cost of Wegovy

One Wegovy pen contains four doses, lasting four weeks. Without insurance, the cost in Canada typically ranges from $400 to $500 per pen. This results in an approximate annual cost of $4,800 to $6,000.

Cost of Zepbound

Each Zepbound pen also contains four doses and lasts four weeks. The cash price in Canada is similar to Wegovy, generally ranging from $400 to $530 per pen. The total yearly cost without insurance is approximately $4,800 to $6,360.

Other costs to keep in mind

It’s recommended to exercise at least 150 minutes a week while using Wegovy and Zepbound. This can be as simple as walking, running, or following a home workout. But if you choose to go to the gym, this will add to your monthly expenses.

However, you might save on your grocery bill as it's recommended to follow a calorie deficit diet. This means you're less likely to spend on junk food or weekly takeout.

While both drugs are similarly priced, the most significant cost factor for most Canadians will be the level of coverage provided by their private insurance plan, as public provincial plans don’t cover these medications for weight loss.

How do Wegovy and Zepbound interact with other medicines?

When Wegovy and Zepbound are used alongside diabetes medication, they can increase the risk of hypoglycemia (low blood sugar). This is because these medications stimulate insulin release, lowering blood sugar levels.

Diabetes medications such as insulin or sulfonylureas (e.g. gliclazide) may require dose adjustments, but they don’t need to be avoided entirely. Your clinician will make sure to closely monitor your blood sugar.

Tirzepatide may affect the absorption of Digoxin (used for heart conditions) and Warfarin (a blood thinner), which could require dose adjustments.

Semaglutide can interact with Acenocoumarol (a blood thinner) by reducing its effectiveness and may slightly increase exposure to Levothyroxine (used for thyroid conditions). These interactions are manageable with monitoring and dose adjustments.

It’s important to inform your clinician about any medication you are taking. For the full list of interactions, read the patient information leaflet.

Both drugs share a similar interaction profile, especially concerning increased hypoglycemia risk with other antidiabetic treatments.

Can Wegovy and Zepbound be used alongside contraception?

Wegovy can be used alongside all types of contraceptives including oral hormonal contraception. However, it’s important to know that side effects like vomiting may affect how well oral contraceptives work.

Zepbound can decrease the effectiveness of oral contraceptives. Oral hormonal contraceptives are digested in the stomach and absorbed into the bloodstream, but Zepbound’s effect to delay stomach emptying can reduce the absorption of oral contraceptives by as much as 55-66%. Therefore, you should avoid using oral contraceptives with Zepbound or use an additional barrier method, like condoms, for added protection.

Non-oral and non-hormonal contraceptives aren’t affected by Zepbound like patches, IUS, or injections, as they are absorbed directly into the bloodstream or vaginal tissue and don’t require digestion. Non-hormonal contraceptives like the copper IUD, don’t require absorption and aren’t affected by Zepbound. For more information, check our guide on Zepbound and contraception.

All types of contraceptives can be used with Wegovy, but oral contraceptives should be avoided with Zepbound.

How we source info:

When we present you with stats, data, opinion or a consensus, we’ll tell you where this came from. And we’ll only present data as clinically reliable if it’s come from a reputable source, such as a state or government-funded health body, a peer-reviewed medical journal, or a recognized analytics or data body. Read more in our editorial policy.