Introduction
A lot of people are buzzing about two drugs currently out on the market: Semaglutide and Mounjaro. Because of their efficacy in helping shed pounds, doctors prescribe both of them as weight loss drugs.
Because both drugs are popular, some people may be confused between the two. How are they the same and how are they different?
In this article, we provide an in-depth comparison of semaglutide vs Mounjaro. Hopefully, it won’t just shed light on their differences and similarities, but inspire a meaningful discussion with your healthcare provider. As with any medication, it is best to seek an expert’s advice.
What is semaglutide?
Before we put semaglutide head-to-head with Mounjaro, let’s take a look at each of them. What are they made of and how do they work?
How semaglutide works
Semaglutide belongs to a class of drugs, glucagon-like peptide-1 receptor agonists, or GLP-1 Ras. Whenever we finish eating and blood sugar levels are high, the hormone GLP-1, triggers insulin release to reduce blood glucose. GLP-1 receptor agonists like semaglutide mimic GLP-1, prompting the release of insulin.
Another effect of taking semaglutide is that it delays digestion or gastric emptying. It makes a person feel fuller for longer. As a result, that person doesn’t feel like eating as much and ends up losing weight.
In the market
Semaglutide is the active ingredient shared by the anti-diabetic drug Ozempic and the anti-obesity drug Wegovy. Both of these have skyrocketed in popularity, with social media shining the spotlight on them.
Semaglutide also has a third brand, Rybelsus, which, just like Ozempic treats type 2 diabetes. You administer Ozempic and Wegovy subcutaneously (injecting under the skin) while you take Rybelsus orally (tablet format). Danish pharmaceutical company manufactures Novo Nordisk.
Although many doctors prescribe Ozempic off-label for weight loss, only Wegovy has FDA approval for weight loss and obesity.
Dosage of semaglutide
Ozempic comes in 0.5 mg, 1 mg, and 2 mg injectable pens and you should administer it once a week. As a starting dose, patients must take it in 0.25 mg doses once weekly for the first four weeks.
Wegovy also comes in an injectable pen but in five various dose strengths, from 0.25 mg to 2.4 mg. Its starting dose is 0.25 mg once weekly for the first four weeks. As subcutaneous medications, patients should be careful not to inject Ozempic or Wegovy into the muscle or vein.
On the other hand, Rybelsus comes in 30-tablet bottles containing 3 mg, 7 mg, or 14 mg doses of the drug. You take it once daily, at a starting dose of 3 mg for the first 30 days.
Administration
You can inject Ozempic and Wegovy in three different areas: the 1) abdomen, 2) thigh, or 3) upper arm. Administer these with or without meals and at any time of the day. For the best results, Novo Nordisk notes it is best to take semaglutide along with a healthy diet and exercise.
Meanwhile, with Rybelsus, you should take it on an empty stomach the first time you wake up for the day. By an empty stomach, this means no food, no drink, no oral medications, no vitamins, and no supplements.
You should take the drug with a sip of plain water, no more than four ounces. Swallow the tablet whole and do not cut, crush, or chew it. After 30 minutes, you can eat, drink, or take other oral medications, vitamins, or supplements.
What is Mounjaro? What is tirzepatide?
Now that we’ve defined semaglutide, let’s take a closer look at Mounjaro.
Mounjaro is an anti-diabetic drug by American pharmaceutical company Eli Lilly. Its active ingredient, tirzepatide, is a direct competitor of semaglutide. Apart from Mounjaro, tirzepatide also goes by the brand name Zepbound, which treats obesity. Basically, Mounjaro and Zepbound are the Ozempic and Wegovy of Eli Lilly.
Correspondingly, you can directly compare semaglutide to tirzepatide, while you can compare Mounjaro to Ozempic.
How does tirzepatide work?
Similar to semaglutide, tirzepatide is also a GLP-1 Ra. It copies GLP-1 with its insulin-triggering action. However, unlike semaglutide, glucose-dependent insulinotropic polypeptide (GIP) makes up tirzepatide. The small intestine produces the hormone GIP, which plays an important role in lipid metabolism.
With its dual composition of GLP-1 Ra and GIP, tirzepatide may offer an additional boost in the weight loss department.
Dosage and administration
Like Ozempic and Wegovy, Mounjaro and Zepbound are injectable pens and you administer them once weekly any time in the day.
Mounjaro comes in 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg doses. Just like Ozempic and Wegovy, you must administer it subcutaneously in the abdomen, thigh, and upper arm. A key difference between Mounjaro and semaglutide pens, is that Mounjaro comes in single-dose pens that require no mixing.
Zepbound, on the other hand, is also available in single-dose pens, and in the same doses sa Mounjaro. It is also injected under the skin in the abdomen, thigh, and upper arm.
Although only Zepbound has FDA approval for weight management, Mounjaro is often prescribed for its off-label for weight loss.
Semaglutide and Mounjaro: Safety and efficacy
Many clinical studies prove the safety and efficacy of semaglutide and tirzepatide. In a review, scientists evaluated and compared two drugs’ efficacy and safety in patients with type 2 diabetes.
The researchers found that:
- In lower doses of subcutaneous semaglutide, tirzepatide was more effective in reducing the average blood sugar level over and body weight.
- At higher doses, oral semaglutide was more effective in reducing blood sugar levels and body weight than tirzepatide.
In terms of safety, the review also noted that:
- 1 mg and 7 mg doses of subcutaneous semaglutide and 5 mg, 10 mg, and 15 mg of tirzepatide did not increase incidence of GIAEs;
- Subcutaneous semaglutide was more effective than insulin in reducing blood sugar levels and body weight.
Despite high incidence of gastrointestinal adverse events (GIAEs), semaglutide and tirzepatide showed positive anti-diabetic benefits within an acceptable safety profile.
Another study found that tirzepatide was more effective in reducing glycated hemoglobin levels and body weight than semaglutide.
The most common side effects were GIAEs such as nausea, diarrhea, and vomiting, but these were primarily mild to moderate.
Comparing their side effects
It’s clear that a common adverse effect shared by semaglutide and tirzepatide are gastrointestinal and is typically mild to moderate.
The moderate side effects of the two drugs include (in no particular order):
- abdominal pain
- constipation or diarrhea
- upset stomach, nausea, and vomiting
- headaches
- fatigue
- low blood sugar (hypoglycemia)
Semaglutide and tirzepatide’s more severe side effects include:
- Allergic reactions
- Changes in eyesight
- Gallbladder issues
- Pancreatitis
- Kidney failure
Both drugs also have boxed warnings on the risk of developing thyroid C-cell tumors. Boxed warnings are the FDA’s most serious type of warning.
In a lab rats study, researchers found these developed thyroid tumors or medullary thyroid carcinoma on semaglutide. Despite these results, it is still unknown whether semaglutide may also potentially cause the same in humans.
Which one is more affordable?
A key determining factor for patients to choose one drug over the other is its level of affordability.
According to a November 2024 report, semaglutide brands had the following pharmacy retail prices for one month’s supply:
- Ozempic: $830-870 (list price at $968.52)*
- Wegovy: $1,237-$1,340 (list price at $1,349.02)*
- Rybelsus: $848-$917 (list price at $968.52)*
Meanwhile, Zepbound costs over a thousand dollars ($1,060*) for a 28-day supply. On the other hand, Mounjaro typically costs between $1,000* to $1,200* a month.
Although tirzepatide costs more, research shows it is more effective than semaglutide in reducing blood sugar levels and body weight.
Conclusion
Semaglutide and Mounjaro are buzzwords making a wave in the anti-diabetic and weight loss space because of their efficacy. Celebrities have lost a significant amount of weight due to the two drugs.
Studies have proven how effective semaglutide and Mounjaro are in lowering glycemic levels in the blood and promoting weight loss. Despite a high incidence of gastrointestinal adverse effects (nausea, diarrhea, vomiting), both still have an acceptable safety profile.
As they are both popular, some people might be confused between the two of them.
To clarify, semaglutide is the generic name and the active ingredient in Ozempic, Wegovy, and Rybelsus. Meanwhile, tirzepatide is the generic name and active ingredient found in Mounjaro and another medication, Zepbound. The comparison would be more suitable between semaglutide and tirzepatide and between Ozempic and Mounjaro. The two brands are both FDA-approved for treating type 2 diabetes.
Both semaglutide and tirzepatide are GLP-1 Ras. They both mimic how the gut-based hormone GLP-1 triggers the pancreas to release insulin to reduce blood sugar levels. A common effect is delayed gastric emptying, causing patients to feel fuller for longer and lose weight.
To achieve desired results, patients must properly administer semaglutide and tirzepatide, in addition to diet and exercise.
Although semaglutide and tirzepatide share side effects like nausea, diarrhea, constipation, and vomiting, many are mild to moderate in nature.
As of November 2024, a month’s supply of semaglutide costs $830-870 a month without insurance. Meanwhile, tirzepatide costs between $1,000 to $1,200 for a one-month supply. Despite the heftier price tag, studies show that tirzepatide is more effective overall in treating type 2 diabetes and obesity.
As with any medication, patients must consult their healthcare provider before incorporating either semaglutide or tirzepatide in their treatment plan.
