Many treatment options now exist for obesity, including injections for weight loss management. Two injectables have shown promising results: Tirzepatide and Wegovy.
In addition to diet and exercise, these two drugs can help you lose weight effectively.
In this article, we will compare tirzepatide and Wegovy, examining their mechanisms of action, efficacy in weight loss, side effects, and eligibility for use.
Key Takeaways
- Tirzepatide and Wegovy are highly effective injectable weight loss medications. Tirzepatide activates GLP-1 and GIP receptors, while Wegovy activates only the GLP-1 receptor.
- In trials, users of tirzepatide experienced up to a 20% reduction in body weight after 72 weeks of use.
- Studies have shown that Wegovy users can experience up to 15% reduction in body weight after 68 weeks.
- Tirzepatide and Wegovy have similar side effect profiles, with gastrointestinal symptoms like nausea and vomiting being the most common.
What is Tirzepatide?
Tirzepatide is a relatively new medication that was originally FDA-approved for treating type 2 diabetes under the brand name Mounjaro.
Subsequently, the drug became approved for weight loss under the brand name Zepbound. This drug is also available as compounded tirzepatide, which helps curb the shortage of branded options.
How Tirzepatide Works
Tirzepatide acts on the glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptors as an agonist. This drug stimulates your pancreas to increase insulin secretion.
At the same time, glucagon secretion is reduced. Tirzepatide also slows gastric emptying (the rate at which your stomach empties its content). Additionally, tirzepatide acts on some brain areas to reduce your appetite and prevent you from overeating.
Clinical Trials and Effectiveness
Many clinical trials have been conducted to assess Tirzepatide's effectiveness in weight loss management. The SURMOUNT-1 trial involving 2539 participants recorded an average of 21% weight loss over 72 weeks. This study also showed that 91% of participants had more than 5% weight loss with 15 mg of tirzepatide.
Common Side Effects
The most commonly reported side effects of tirzepatide are gastrointestinal issues. Here are some of the common adverse effects:
- Nausea
- Vomiting
- Diarrhea
- Constipation
- Fatigue
- Low blood sugar
Fortunately, most of these side effects usually resolve after a few weeks on the drug. Less common side effects include allergic reactions, gallbladder issues, and pancreatitis. Contact your healthcare provider if you have any concerns about the side effects.
What is Wegovy?
Wegovy is an injectable weight loss medication created by Novo Nordisk. Its active ingredient is semaglutide, which is also available under the brands Ozempic and Rybelsus. Of all three semaglutide brands, Wegovy is the only one FDA-approved for weight loss.
How Wegovy Works
Wegovy (semaglutide) is a sole GLP-1 receptor agonist. Like Tirzepatide, Wegovy regulates blood glucose and reduces appetite, helping you lose weight.
Clinical Trials and Effectiveness
In 2021, a study was conducted among 1961 participants with body mass index (BMI) ≥ 30 kg/m² or ≥27 kg/m² with at least one weight-related health condition. This showed that Wegovy resulted in an average of 15% weight loss after 68 weeks of use.
Common Side Effects
Being a GLP-1 receptor agonist, Wegovy has a similar side effect profile as Tirzepatide. The majority of the side effects are also gastrointestinal. However, studies show that more patients experience fewer side effects from Wegovy (semaglutide) than tirzepatide. Some of these side effects are:
- Nausea
- Vomiting
- Diarrhea
- Constipation
- Fatigue
- Low blood sugar
- Stomach pain
Like tirzepatide, some Wegovy users may experience less common side effects such as allergic reactions, pancreatitis, and gallbladder problems. Contact your healthcare provider immediately if you notice any unusual side effects.
What Do GLP-1 and GIP Hormones Do?
GLP-1 Hormone
Glucagon-like peptide-1 (GLP-1) is a naturally occurring hormone in your gut. It belongs to a class of hormones called incretins that stimulate insulin secretion. This hormone has several physiological functions that make it a target for drugs directed at weight loss and type 2 diabetes. Some of these functions are:
- GLP-1 stimulates your pancreas to secrete insulin and regulate blood sugar levels. Glucagon, a hormone that increases blood sugar, is reduced by GLP-1. This makes the drug invaluable for glycemic control in type 2 diabetes.
- This hormone also acts on some areas of your brain to reduce appetite.
- GLP-1 inhibits gastric emptying and the motility of your gut. In addition to a reduced appetite, this gives you a sense of fullness and reduces your calorie intake, facilitating weight loss.
Drugs like tirzepatide and Wegovy (semaglutide) target the GLP-1 receptor to activate it and turn on its weight-loss effect.
GIP Hormone
Glucose-dependent insulinotropic polypeptide (GIP) is also a naturally occurring hormone in your body with actions similar to GLP-1. GIP increases insulin release, reduces appetite, and delays gastric emptying. All these actions result in good glycemic control and weight loss.
Head to Head Comparison
Tirzepatide vs Wegovy: Mechanisms of Action
Tirzepatide and Wegovy have similar mechanisms of action with a slight difference. Both drugs are GLP-1 agonists. However, tirzepatide has dual actions by acting on both GLP-1 and GIP receptors. This dual action of tirzepatide may result in more weight loss than with Wegovy.
Tirzepatide vs Wegovy: Efficacy in Weight Loss
Both tirzepatide and Wegovy are great for weight loss; however, tirzepatide may have an edge here. In 2022, a systematic review comparing both drugs found that tirzepatide resulted in more weight loss than Wegovy.
Tirzepatide vs Wegovy: Clinical Trials
A clinical trial showed that you can lose up to 15% of your starting body weight after 68 weeks of using Wegovy (semaglutide). With tirzepatide, studies have shown that users can potentially experience up to 20% (5% more than with Wegovy) reduction in their initial body weights after 72 weeks of use.
Tirzepatide vs Wegovy: Dosage and Administration
Both tirzepatide and Wegovy are administered as once-weekly injections. Tirzepatide is available in six dosages: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg. Typically, you will start out at 2.5 mg once weekly, which is gradually increased every four weeks until the maximum dose of 15mg.
Wegovy comes in dosages of 0.25 mg, 0.5 mg, 1.0 mg, 1.7 mg, and 2.4 mg. You also start at the lowest dose of 0.25 mg and gradually increase it every four weeks until you reach the maximum dose of 2.4 mg.
Both drugs are injected subcutaneously (under your skin) into your stomach, thighs, or upper arms. There are no significant differences in administering both drugs.
Medical Recommendations and Considerations
Who Should Consider Tirzepatide?
People who want to lose weight can consider tirzepatide if they meet these criteria:
- Adults with BMI ≥ 30 kg/m²
- Adults with BMI ≥ 27 kg/m² with at least one weight-related health complications
Tirzepatide may not be suitable for children and is only recommended for individuals aged 18 or more. Due to a shortage in Zepbound and Mounjaro, your healthcare provider might recommend getting compounded tirzepatide online.
Who Should Consider Wegovy?
Wegovy is recommended for individuals looking to lose weight and meet these criteria:
- Adults with BMI ≥ 30 kg/m²
- Adults with BMI ≥ 27 kg/m² with at least one weight-related health complications
- Children aged 12 years and older with BMI ≥ the 95th percentile
Wegovy (semaglutide) also has cardiovascular benefits; you may prefer it if you have a heart-related condition.
Contraindications and Precautions
Tirzepatide and Wegovy may not be suitable for you if you have some conditions. Some of these are:
- A personal or family history of thyroid cancer, particularly medullary thyroid carcinoma
- A personal or family history of an endocrine tumor called Multiple Endocrine Neoplasia type 2 (MEN-2)
- A history of severe allergic reactions to either tirzepatide or Wegovy.
Also, if you have a history of kidney or pancreas disease or are breastfeeding, inform your doctor before starting tirzepatide or Wegovy.
Conclusion
Tirzepatide and Wegovy are potent weight loss injectables; however, research shows that tirzepatide may be slightly more effective in weight loss than Wegovy. This is because tirzepatide acts on GLP-1 and GIP receptors, while Wegovy only mimics the GLP-1 hormone.
Discuss your weight loss goals with your healthcare provider. They can assess your health and assist you in making an informed decision on the right drug.
Frequently Asked Questions
Should I switch from semaglutide to tirzepatide?
You may consider switching from semaglutide to tirzepatide if you are not achieving your weight loss goals on the former. However, discuss with your healthcare provider to assist you in making an informed decision before switching. It is crucial that you do not use both drugs simultaneously to prevent severe side effects.
Is tirzepatide the same as Wegovy?
No! Tirzepatide has dual actions on GIP and GLP-1, while Wegovy is a semaglutide brand that acts on only GLP-1. Both medications are helpful for weight loss.
Why am I not losing weight on tirzepatide?
There could be several reasons why you are not seeing any progress with tirzepatide. It could be due to not being in a calorie deficit, improper dosing, or underlying health conditions. Discuss with your healthcare provider to identify any issues and adjust your treatment plan.
Is tirzepatide hard on the kidneys?
Tirzepatide has not been shown to cause renal impairment. Studies have shown that tirzepatide may have some protective effects on the kidneys in individuals with type 2 diabetes.
How much weight can you lose in a month with Wegovy?
Studies have shown that using Wegovy can help you lose up to 2% of your body weight in one month.
Sources
- https://edition.cnn.com/2024/02/29/health/obesity-underweight-world-who-study/index.html
- https://www.ncbi.nlm.nih.gov/books/NBK551568/
- https://www.ncbi.nlm.nih.gov/books/NBK546653/
- https://www.nejm.org/doi/full/10.1056/NEJMoa2206038
- https://www.nejm.org/doi/full/10.1056/NEJMoa2032183
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8987449/
- https://www.wegovy.com/#:~:text=Wegovy%C2%AE%20is%20an%20injectable,plan%20and%20increased%20physical%20activity.
Disclaimer
Off-Label Use: When discussing off-label uses, such as using Ozempic for weight loss, make it clear that this is not FDA-approved for that purpose. For example, you can add a disclaimer like: “While Ozempic is primarily approved for treating Type 2 diabetes, some healthcare providers may prescribe it off-label for weight loss. However, this use is not FDA-approved.”
Medical Advice Disclaimer: Clearly state that the article is for informational purposes only and not a substitute for professional medical advice. Encourage readers to consult with their healthcare provider before starting any new medication.