GLP-1 drugs like Ozempic and Mounjaro are widely used, but side effects vary. Experts explain why people respond differently to these medications.
Different Reactions to Popular Weight Loss Drugs
Drugs like Ozempic, Wegovy, Mounjaro, and Zepbound have become popular for weight loss. These medications are all part of the GLP-1 receptor agonist class. However, many people report very different experiences when using them.
Nausea and other stomach-related problems are common with these drugs. In some cases, the side effects are so severe that patients stop using the medication or switch to another.
Switching Medications Is Common
A recent 2024 study by Truveta found that about 11% of users of GLP-1 medications switched to a different drug within five years. This shows that switching is not unusual.
Celebrity Amy Schumer recently talked about her own experience. She said that semaglutide made her very sick. But after switching to tirzepatide, she felt much better. On social media and in interviews, she shared that she had extreme nausea on Ozempic but had a much smoother time with Mounjaro.
Why Do Side Effects Vary?
Doctors say individual reactions to these drugs depend on many factors. These include the medication itself, age, sex, genetics, diet, and even exercise habits.
Common Side Effects of Semaglutide and Tirzepatide
Both semaglutide and tirzepatide work by targeting GLP-1 receptors in the brain, pancreas, and digestive tract. These drugs help lower blood sugar, slow digestion, and reduce appetite.
Typical side effects include:
- Nausea
- Acid reflux or indigestion
- Constipation
- Loss of appetite
- Diarrhea
- Vomiting
- Stomach pain
The weight-loss versions of these drugs may also cause extra side effects. For example:
- Wegovy: Headache, dizziness, gas, bloating, sore throat, runny nose
- Zepbound: Hair loss, allergic reactions, or injection site pain
Most of these symptoms tend to fade as the body gets used to the drug. Also, side effects often increase with higher doses.
The Main Difference Between the Drugs
Semaglutide is a pure GLP-1 receptor agonist. Tirzepatide works on two hormones: GLP-1 and GIP (glucose-dependent insulinotropic polypeptide). GIP also helps lower blood sugar and improves fat levels in the body. This dual-action effect may explain why tirzepatide sometimes results in more or fewer side effects, depending on the person.
Pharmacists and doctors have noticed both patterns. Some patients handle tirzepatide better, while others find semaglutide easier to tolerate.
For example, some patients have fewer side effects when starting tirzepatide slowly. Others may feel better after switching from semaglutide, or vice versa. Every body reacts differently, and lifestyle, other medications, and meal choices also play a role.
Factors That Influence Side Effects
Experts say the following can impact how your body responds to GLP-1 drugs:
- Genetics and age
- Sex and hormone levels
- Starting dose and how fast it increases
- Diet and how much food you eat
- Exercise habits
- Hydration and water intake
If your first dose is too high, side effects like nausea are more likely. Lower doses that increase slowly tend to be easier on the stomach.
How to Reduce Side Effects From GLP-1 Drugs
There are steps you can take to reduce the side effects of semaglutide or tirzepatide:
- Start with a low dose and slowly increase it
- Eat smaller meals more often
- Avoid greasy foods, sweets, and red meats like steak
- Use anti-nausea or constipation medications if needed
- Stay hydrated by drinking enough water every day
Some people forget to drink water when their appetite is reduced. This can lead to dehydration and, in rare cases, serious issues like kidney failure.
When to Talk to Your Doctor
If you continue to feel sick or uncomfortable, talk to your healthcare provider. They might suggest stopping the drug for a while. Then, they may recommend trying a lower dose, changing your diet, or switching to another medication.
Every person responds to treatment differently. That’s why obesity specialists often create custom plans based on individual needs.
As Dr. Jorge Moreno said, “Obesity treatment is not a one-size-fits-all approach.”
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