If you’ve been considering medical intervention weight management, then there may be a couple of drugs that you’ll have heard of. One is Wegovy, and the other is tirzepatide.
But which is the best for you and your weight management goals?
In this article we’ll cover:
- What Wegovy is
- What tirzepatide is
- The main differences between the two drugs
- Information about Wegovy clinical trials
- Information about tirzepatide clinical trials
- Our guide to choosing which drug is best for you
- Frequently asked questions.
Let’s get started!
What Is Wegovy?
Wegovy is a weight management drug created by Novo Nordisk that contains an active ingredient of semaglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist. Semaglutide can affect your appetite and feelings of fullness, so that you can go without eating food for longer.
Because Wegovy is a GLP-1 receptor agonist, it will imitate the effects of the GLP-1 hormone in the pancreas, which is released after a meal. One of its benefits is that it sends signals to the brain to stop eating, which means you won’t be as hungry, and you’ll feel full for longer.
Wegovy is administered in doses of 0.25 mg to 2.4 mg. It is administered as an injection subcutaneously, usually into the thigh, once a week. It is currently the only semaglutide product approved for weight management and treatment of obesity.
What Is Tirzepatide?
Tirzepatide, sold under the brand name Mounjaro, is an approved glycemic control drug created by Eli Lilly and used by people with type 2 diabetes who need assistance with insulin resistance. It is also used as a weight management drug, and may help some people lose up to 25 lbs — around 11 kg.
Like Wegovy, tirzepatide is a GLP-1 receptor agonist. It is also a glucose-dependent insulinotropic polypeptide (GIP) receptor agonist, and lowers A1C levels. GIP receptors stimulate the secretion of insulin in the body, and are valuable as a treatment for type-2 diabetes.
Additionally, both GIP and GLP-1 receptor hormones work together when it comes to weight management, as they enhance the messages sent to the brain that prevent overeating.
Mounjaro is sold in six different tirzepatide dosages, ranging from 2.5 mg to 15 mg. It comes in a pen and is injected into the thigh once a week, much like Wegovy.
Wegovy vs. Tirzepatide
The main difference between the two medications is that while Wegovy is a semaglutide and mimics the GLP-1 receptor agonist, reviews have shown that tirzepatide is able to mimic both GLP-1 and GIP receptor agonists. This is known as a “twincreatin” medicine.
The active compounds (semaglutide and tirzepatide) are also different, though they have similar biological effects.
Tirzepatide shows more promising results in studies and clinical trials when it comes to weight management and demonstrates greater weight loss. It also has a broader range of use, as it can be used for type-2 diabetes patients as well as those seeking weight management intervention.
However, semaglutide has lower dosage requirements and likely has wider availability in the market, as it’s been available for longer.
Depending on your personal medical circumstances, your medical team may be able to advise you on which drug is recommended for certain patients better. If you’re considering taking either drug for weight management, you should discuss fully with them to make an informed decision.
Neither drug is suitable for the treatment of those with type 1 diabetes. When used as weight loss drugs, another benefit includes reducing the risk of major cardiovascular events. This includes heart disease, stroke, reduction of high cholesterol, lowering high blood pressure, and more.
Both drugs are most effective when combined with lifestyle changes, such as a healthy diet and regular exercise. Doing so is not only strongly recommended, but may also affect your energy levels and metabolism positively.
Clinical Trials for Wegovy
Overview of Clinical Trials
In the brand-led study for Wegovy, the drug was trialled on 1,961 adult participants with obesity over 68 weeks. Around 2/3 of the group took Wegovy weekly for the course of the 68 weeks, and the other 1/3 took a placebo. These groups were completely random.
Efficacy Results from Clinical Trials
Wegovy was estimated to have a mean weight loss of 14.9% in the group that took it. The observed mean weight loss was 15.6%. The placebo mean weight loss was 2.8%, after an estimated mean weight loss of 2.4%.
The data showed that the majority of the patients taking Wegovy had meaningful weight loss, with 1 in 3 patients losing over 20% of their body mass.
Safety Profile from Clinical Trials
6.8% of patients who were treated with Wegovy discontinued the treatment after adverse reactions, and 3.2% of patients given the placebo did the same.
3.2% of patients treated with Wegovy and 0.7% of patients treated with placebo discontinued the treatment due to adverse gastrointestinal reactions.
Side Effects Reported in Clinical Trials
The side effects reported in the clinical trials were nausea, diarrhea, and vomiting. Also high in numbers were constipation and abdominal pain.
Clinical Trials for Tirzepatide
Overview of Clinical Trials
The clinical trials for tirzepatide against the placebo (named SURPASS-1) measured the A1C levels in 478 adults in groups at a 1:1:1:1 ratio of 5 mg, 10 mg, 15 mg, and placebo. These adults all had type-2 diabetes and issues with glucose levels control. The patients were treated with the various doses and the placebo over 40 weeks.
Clinical trials were also held to compare the effects of tirzepatide on adults with type-2 diabetes, with the effects of Ozempic 1 mg (semaglutide), Tresiba, and insulin glargine. The loss of body mass was also observed.
Efficacy Results from Clinical Trials
The patients’ A1C levels dropped a mean of 1.87% (5 mg), 1.89% (10 mg), 2.07% (15 mg), and rose 0.04% in the group who were given the placebo.
In the weight reduction observations, the mean body mass loss was 7.9% (5 mg), 9.3% (10 mg), 11.0% (15 mg), and 0.9% (placebo).
As you can see, this shows that Wegovy has better efficacy than tirzepatide for individuals for weight management, even bearing in mind that the terzepatide clinical trial was only 40 weeks vs. 68 weeks for Wegovy.
Safety Profile from Clinical Trials
The mean discontinuation rate for tirzepatide 5 mg was 3%, followed by 5.4% for the 10 mg, 6.6% for 15 mg, and 0.4% for the placebo. The patients mainly discontinued due to adverse reactions.
While there is a small difference in those who discontinued following adverse reactions, it’s very similar, showing that neither drug has a better safety profile than the other, though Wegovy shows lower rates of discontinuation (albeit very minor and on a lower overall dosage).
Side Effects Reported in Clinical Trials
The most common side effects of tirzepatide in the clinical trials were nausea, diarrhea, and increased appetite. These were followed by vomiting and constipation.
Both trials for Wegovy and tirzepatide showed similar side effects, though it should be noted that tirzepatide likely carries fewer contraindications than semaglutide, which is known to contraindicate with multiple drugs, vitamins, and herbal supplements.
Tirzepatide vs. Wegovy: Choosing the Right Fit for You
How They Work
Tirzepatide and Wegovy are both GLP-1 receptor agonists. Research has shown that they both have potential to assist in weight management. GLP-1 receptor agonists affect the hunger centres in the brain, meaning that your appetite will lessen, and the feeling of fullness (satiety) will last longer.
Because tirzepatide is a dual inhibitor, it is also a GIP receptor agonist. This means it can stimulate the secretion of insulin, and lower the blood sugar levels on someone with type-2 diabetes.
This is its main purpose, although it can be used as a weight management drug, as it works with GLP-1 receptor agonists to affect the signals sent to the brain around fullness.
The Dosage
Wegovy comes in five dosage amounts of 0.25 mg, 0.5 mg, 1 mg, 1.7 mg, and 2.4 mg. Patients will usually start on the 0.25 mg dosage, and gradually increase over four weeks to the 4.2 mg dosage.
Tirzepatide comes in six dosage sizes of 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg. Most patients usually start at 2.5 mg, and graduate towards 5 mg over 4 weeks. Then the patient can slowly work up to 15 mg if they need a higher dosage.
Each patient stays on their current tirzepatide dosage for at least four weeks. Both Wegovy and tirzepatide are injected once weekly subcutaneously into the thigh.
Neither drug is easier to administer than the other or requires less frequent dosing.
Health Canada Approval
Health Canada approved Wegovy as a chronic weight management drug in 2021.
Additionally, Mounjaro (tirzepatide) was approved in 2023 for adult patients with type-2 diabetes when used alongside a healthy diet and exercise.
Average Body Weight Loss
In the clinical trial, the Wegovy patients lost an average weight of 15% of their starting weight (around 232 lb/105 kg).
In the trial for tirzepatide, weight loss ranged from around 12 lbs (5 kg) to 25 lbs (11 kg).
Key Takeaways
Both tirzepatide (Mounjaro) and Wegovy have been shown to help assist in weight management. However, the effects of tirzepatide for weight management in adults without diabetes has not been tested, and the drug is only known for sure to reduce body mass of adults for type-2 diabetes.
Both drugs (semaglutide and tirzepatide) are GLP-1 receptor agonists, which affect the hunger centre in the brain. Tirzepatide is also a GIP receptor agonist, which lowers the glucose levels in the blood, as well as works with GLP-1 receptor agonists to deliver messages to the brain around fullness and satiety.
According to both trials, Wegovy is able to positively affect weight management more than tirzepatide. However, it’s important to remember that these trials are quite different in terms of group size and other factors, so they can’t be 100% accurately compared, nor did they measure if one is better tolerated by patients than the other.
Regardless, if you’re considering weight management intervention, either drug may offer a better quality of life improvement. You should discuss with your medical team so that you’re fully aware of the pros, cons, and suitability for you.
FAQs
What are the unique benefits of Wegovy and tirzepatide?
When it comes to the unique benefits of Wegovy and tirzepatide, both may assist with weight management. However, Wegovy is only used as a weight management tool alongside lifestyle intervention measures, such as a healthy diet and regular exercise. Tirzepatide, on the other hand, is primarily used to control the blood sugars of adults with type-2 diabetes.
As such, if tirzepatide is being used as a weight management tool, your health insurance may not cover this. Wegovy, on the other hand, is more likely to be covered, meaning you’ll pay less out of pocket for the drug.
Can Wegovy and tirzepatide be used in combination for weight loss?
More than one GLP-1 receptor agonist should not be taken at the same time. Therefore, it is not a good idea to take tirzepatide and Wegovy simultaneously.
It’s recommended that neither Wegovy nor tirzepatide should be used solely as a weight management tool, but alongside a healthy diet and exercise regime. Not only is this better for your overall general health, it also provides more sustainable weight loss.
How long does it take to see weight loss results with Wegovy and tirzepatide?
When starting Wegovy, weight loss can begin within 4–12 weeks. However, it may take several months before you see significant results.
On the other hand, tirzepatide took about 16 weeks in clinical trials for the body mass to be lowered by 5%. This shows that tirzpatide potentially offers faster results than Wegovy.
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