Are you looking for a medication to help you lose weight? If so, you may have heard of two drugs that are making headlines: tirzepatide and semaglutide. Both of them are injections that work by mimicking hormones that reduce appetite and improve blood sugar control. But how do they compare in terms of effectiveness, safety, and cost? In this article, we will answer these questions and more.
What are tirzepatide and semaglutide?
Tirzepatide and semaglutide belong to a class of drugs called GLP-1 receptor agonists. GLP-1 stands for glucagon-like peptide-1, a hormone that your gut releases after eating. It stimulates insulin secretion, lowers blood sugar levels, and makes you feel full. GLP-1 receptor agonists are synthetic molecules that bind to the same receptors as GLP-1 and have similar effects.
However, tirzepatide is not just a GLP-1 receptor agonist. It is also a GIP receptor agonist. GIP stands for glucose-dependent insulinotropic polypeptide, another hormone that your gut releases after eating. GIP also stimulates insulin secretion, lowers blood sugar levels, and makes you feel full. Tirzepatide is a dual GIP and GLP-1 receptor agonist, which means it mimics both hormones at the same time.
Semaglutide, on the other hand, is a selective GLP-1 receptor agonist. It only binds to the GLP-1 receptors and does not affect the GIP receptors.
How effective are tirzepatide and semaglutide for weight loss?
Both tirzepatide and semaglutide are effective for weight loss in clinical trials. However, tirzepatide seems to have an edge over semaglutide in terms of the amount of weight loss achieved.
According to a 2023 study, tirzepatide resulted in greater weight loss than semaglutide in people with type 2 diabetes. The study compared three doses of tirzepatide (5 mg, 10 mg, and 15 mg) with one dose of semaglutide (1 mg), all given once weekly for 40 weeks. The results were as follows:
| Drug | Dose | Average weight loss |
|---|---|---|
| Tirzepatide | 5 mg | 9.5 kg (20.9 lbs) |
| Tirzepatide | 10 mg | 11.3 kg (24.9 lbs) |
| Tirzepatide | 15 mg | 12.4 kg (27.3 lbs) |
| Semaglutide | 1 mg | 7.8 kg (17.2 lbs) |
As you can see, tirzepatide at all doses was superior to semaglutide in terms of weight loss. The difference was statistically significant and clinically meaningful.
Another 2021 study also found that tirzepatide was more effective than semaglutide in people with obesity who did not have diabetes. The study compared four doses of tirzepatide (2.5 mg, 5 mg, 10 mg, and 15 mg) with one dose of semaglutide (2.4 mg), all given once weekly for 68 weeks. The results were as follows:
| Drug | Dose | Average weight loss |
|---|---|---|
| Tirzepatide | 2.5 mg | 13% |
| Tirzepatide | 5 mg | 16% |
| Tirzepatide | 10 mg | 19% |
| Tirzepatide | 15 mg | 23% |
| Semaglutide | 2.4 mg | 15% |
Again, tirzepatide at all doses was superior to semaglutide in terms of weight loss. The difference was statistically significant and clinically meaningful.
These studies suggest that tirzepatide may offer an extra weight loss boost compared to semaglutide, possibly because of its dual action on both GIP and GLP-1 receptors.
How do tirzepatide vs semaglutide compare with other weight loss medications?
Tirzepatide and semaglutide are not the only medications available for weight loss. Other drugs work in different ways to help you shed some pounds. Here is a table that summarizes some of the key features of four medications: tirzepatide, semaglutide, liraglutide, and orlistat.
| Medication | Class | Mechanism | Approved for | Average weight loss | Common side effects | Cost |
|---|---|---|---|---|---|---|
| Tirzepatide | Dual GIP and GLP-1 receptor agonist | Mimics hormones that reduce appetite and improve blood sugar control | Type 2 diabetes (not yet approved for weight loss) | 9.5 to 23% depending on dose | Nausea, vomiting, diarrhea, constipation, abdominal pain, low blood sugar, injection site reactions, headache, fatigue, dizziness, allergic reactions | Unknown (likely similar to semaglutide) |
| Semaglutide | Selective GLP-1 receptor agonist | Mimics a hormone that reduces appetite and improves blood sugar control | Type 2 diabetes and weight loss (Wegovy) | 7.8 to 15% depending on dose | Nausea, vomiting, diarrhea, constipation, abdominal pain, low blood sugar, injection site reactions, headache, fatigue, dizziness, allergic reactions | About $1,500 per month |
| Liraglutide | Selective GLP-1 receptor agonist | Mimics a hormone that reduces appetite and improves blood sugar control | Type 2 diabetes and weight loss (Saxenda) | 5 to 10% depending on the dose | Nausea, vomiting, diarrhea, constipation, abdominal pain, low blood sugar, injection site reactions, headache, fatigue, dizziness, allergic reactions | About $1,300 per month |
| Orlistat | Lipase inhibitor | Blocks the absorption of fat from the foods you eat | Weight loss (Xenical and Alli) | 3 to 6% depending on the dose | Diarrhea, gas, leakage of oily stools, stomach pain | About $200 per month for Xenical or $60 per month for Alli |
As you can see, tirzepatide and semaglutide seem to be more effective than liraglutide and orlistat for weight loss. However, they also have more side effects and are more expensive. Orlistat is the only medication that does not require an injection and does not affect blood sugar levels. You should talk to your doctor about which medication is best for you based on your medical history, goals, preferences, and budget.
What are the side effects?
Like any medication, tirzepatide and semaglutide may cause some side effects. The most common side effects are gastrointestinal, such as nausea, vomiting, diarrhea, constipation, and abdominal pain. These side effects are usually mild to moderate in severity and tend to decrease over time as your body adjusts to the medication.
Other possible side effects include low blood sugar, injection site reactions, headache, fatigue, dizziness, and allergic reactions. In rare cases, tirzepatide and semaglutide may cause serious side effects such as pancreatitis (inflammation of the pancreas), gallbladder problems (such as gallstones or inflammation), kidney problems (such as kidney failure or urinary tract infections), thyroid tumors (benign or malignant), and suicidal thoughts.
Before starting tirzepatide or semaglutide for weight loss you should talk to your doctor about your medical history allergies and other medications you are taking. You should also monitor your blood sugar levels regularly and report any unusual symptoms to your doctor.
How much do these cost?
Tirzepatide and semaglutide are both expensive medications. Tirzepatide is not yet approved by the FDA for weight loss so its price is not known. However, it is likely to be similar to semaglutide which costs about $1 500 per month for the weight loss dose of 2.4 mg. This means that a year of treatment with tirzepatide or semaglutide could cost around $ 18,000.
Unfortunately, most insurance plans do not cover tirzepatide or semaglutide for weight loss. This means that you may have to pay out of pocket for these medications. Some drug manufacturers may offer coupons or assistance programs to help lower the cost but these may have eligibility criteria and limitations.
If you are interested in tirzepatide or semaglutide for weight loss you should talk to your doctor and your insurance company about your options. You should also compare the benefits and risks of these medications with other weight loss strategies, such as diet, exercise, behavioral therapy, surgery, or other drugs.
Conclusion
Tirzepatide and semaglutide are both promising medications for weight loss. They work by mimicking hormones that reduce appetite and improve blood sugar control. However, tirzepatide seems to be more effective than semaglutide in terms of the amount of weight loss achieved. Both medications have similar side effects, mostly gastrointestinal. Both medications are also expensive and may not be covered by insurance.
If you are considering tirzepatide or semaglutide for weight loss, you should consult your doctor and weigh the pros and cons of these medications. You should also explore other weight loss options that may suit your needs and preferences better. Remember that weight loss is a journey that requires commitment and support from yourself and others.
