GLP-1 receptor agonists are a group of medications that can effectively address type 2 diabetes and obesity. These medications replicate a naturally occurring hormone in your body known as glucagon-like peptide-1 which influences areas of the brain that control appetite and food consumption, among other things. Consequently, you might notice:
- Reduced hunger and appetite
- Fewer food-focused thoughts
- Feeling full more quickly
- Decreased cravings
When combined with healthy habits and proper nutrition, GLP-1 medications can be a powerful ally in your weight loss journey. However, a notable downside is that most GLP-1 drugs must be administered via injection. And as with any medication, there is a risk of side effects, some of which can be serious. Some frequent side effects include:
- Nausea
- Diarrhea
- Vomiting
A more serious risk associated with GLP-1 drugs is low blood sugar levels (hypoglycemia). However, this risk usually increases only if you are taking another medication known to lower blood sugar.
GLP-1 drugs are not recommended for individuals with a personal or family history of multiple endocrine neoplasia or medullary thyroid cancer. They are also not recommended for those who have had pancreatitis.
How Much Weight You’ll Lose with GLP-1 Drugs
The amount of weight you’ll lose with GLP-1 medications depends on several factors like the specific GLP-1 medication, individual characteristics and dosage. The recommended rate of weight loss is about 0.5-1% of your initial weight per week. That means a person weighing 250 pounds might aim to lose 1.25 to 2.5 pounds weekly. Clinical trials have shown that most people who are taking liraglutide lost over 5% of their body weight over a 56-week period. Those who take semaglutide had 15% average weight loss over a period of 68 weeks. Tirzepatide, which is the newest GLP-1 drug in the market, resulted in an average of 20% weight loss over 72 weeks when given the highest possible dose.
Possible Reasons Why GLP-1 Drugs May Not Help You Lose Weight
Ozempic and Wegovy have been hailed as breakthroughs for managing obesity and overweight conditions. A 2021 clinical trial revealed that 86.2% of over 800 participants achieved “clinically significant” weight loss after taking 2.4 mg weekly doses of semaglutide (marketed as Ozempic and Wegovy) for 68 weeks.
While these results are promising, they also indicate that 13.8% of participants did not experience any significant weight loss. It’s crucial for patients to understand that they could be either responders or non-responders, despite the higher likelihood of a positive response according to the data.
“As with any medication, a single type of prescription will not be suitable for every patient,” says Dr. Meghan Garcia-Webb, MD, who holds triple board certifications in internal medicine, lifestyle medicine, and obesity medicine. “It’s also vital that patients don’t rely solely on one medication for their health success.”
Several factors can contribute to why some patients do not respond to GLP-1 medications:
1. Lifestyle Changes
Clinical trials for semaglutide included lifestyle interventions for both the placebo and medication groups. Dr. Michael L. Glickman, MD, emphasizes that for optimal results with the explaination GLP-1 medications, patients should generally adhere to the six pillars of Lifestyle Medicine:
Regular exercise
Eating a plant-forward diet
Managing stress
Quality sleep
Avoiding substance use
Maintaining strong social relationships
2. Not Taking Medication as Prescribed
“If the medication is not taken as prescribed, such as missing doses or not following instructions on timing or dosage, it may not work effectively,” explains Dr. Yoshua Quinones, MD. Research also indicates that long-term use of the drug is essential for sustained weight loss.
3. Other Medical Issues
Untreated or undiagnosed medical conditions, such as sleep apnea, hypothyroidism or chronic insomnia, can interfere with weight loss efforts. Eating disorders can also complicate the effectiveness of GLP-1 medications. A 2024 review suggested that while GLP-1s might help reduce some eating disorders, more comprehensive data is still needed at this time.
4. Insulin Resistance
Ozempic is designed to help people with diabetes by lowering their A1C levels. However, research indicates that those with insulin resistance may lose less weight on GLP-1 medications. “In patients with type 2 diabetes, the body’s ability to respond to GLP-1 and stimulate insulin secretion is reduced,” Quinones explains. This weakened response can make managing blood sugar levels more challenging and may necessitate alternative treatments or dosage adjustments.
5. Medication Interference
Certain medications like some antidepressants and beta-blockers, can promote weight gain and interfere with the effectiveness of GLP-1 drugs. This is why patients should discuss all their medications with their healthcare provider before starting a GLP-1 medication.