In the past few years, glucagon-like peptide-1 (GLP-1s) medications have transformed the management and treatment of weight loss. This class of medications, initially created to treat type 2 diabetes, has been found to produce profound effects on appetite and energy, marking a new era in weight management.
What Are GLP-1s?
GLP-1 receptor agonists are a type of medications that replicate the effects of the body’s natural incretin hormone GLP-1 (glucagon-like peptide). This hormone is released from the gut in response to meals and then acts on the pancreas and brain. Originally, these medications were used to treat type 2 diabetes.
When used for weight management, GLP-1 receptor agonists have been shown to:
- Regulate appetite and hunger by reducing caloric consumption and making a person feel full faster
- Slowing the emptying of the stomach
- Improving insulin secretion and glucose metabolism
As a result, GLP-1s, combined with a healthy diet and physical activity, profoundly affect energy balance and metabolism, leading to weight reduction.
Commonly Used GLP-1 Receptor Agonists
Several GLP-1 medications have been used for weight management, each having the same mode of action, but the dosage forms and efficacy may vary. Some of the GLP-1 medications that can be used to manage weight are described below.
Semaglutide (Brand names: Wegovy, Ozempic)
Semaglutide is one of the most potent and common medications prescribed for weight loss. As a GLP-1 agonist, it helps reduce hunger and delay gastric emptying, ultimately resulting in weight loss in individuals with obesity. There is extensive research on semaglutide effectiveness; it is prescribed as weekly injections, making adherence to medication convenient.
Tirzepatide (Brand names: Zepbound, Mounjaro)
Tirzepatide is a dual-action medication because it targets both GLP-1 and GIP (gastric inhibitory polypeptide) receptor sites. It is used as a weekly injection and promotes appetite suppression and metabolic effects. Just like other weight loss medications, it’s possible to get a Zepbound prescription online, if deemed appropriate by a licensed medical provider after an assessment.
Liraglutide (Brand names: Saxenda, Victoza)
Liraglutide was one of the first GLP-1 medications approved for weight management. It functions by mimicking the action of the natural GLP-1 hormone to decrease appetite, increase feelings of fullness, and lower total food consumption. Unlike other GLP-1 medications, liraglutide requires a daily injection. Compared to newer GLP-1s like semaglutide and tirzepatide, liraglutide may cause lower weight loss, but it’s still suitable for some patients.
How Do GLP-1s Promote Weight Loss?
GLP-1 medications work to induce weight loss in several ways:
- GLP-1s target hypothalamus receptors to increase fullness and decrease hunger, especially for high-calorie foods, leading to satisfaction with smaller portions and reduced cravings.
- These medications slow digestion and food movement from the stomach, extending the feeling of fullness and reducing hunger between meals.
- GLP-1s improve insulin sensitivity, leading to reduced fat accumulation, improved lipid profiles, decreased inflammation, and visceral fat burning. They also suppress glucagon, which helps reduce food cravings and energy crashes.
Some GLP-1 medications have shown promising effects in addition weight loss, including:
- Reduced blood glucose levels in patients with type 2 diabetes and prediabetes
- Lower cardiovascular risk
- Reduced risk of heart attack and stroke
- Improved blood pressure and cholesterol levels
- Improved insulin sensitivity
Difference Between GLP-1s and Other Weight-Loss Medications
GLP-1s differ from other weight management medications as they address the hormonal and metabolic basis of obesity, rather than acting on hunger and/or calorie intake.
Appetite suppressants, such as phentermine, function by stimulating the CNS in order to decrease hunger; because of certain stimulant-related side effects, phentermine is only approved for short-term use. Fat absorption blockers, such as Orlistat, facilitate weight reduction by inhibiting the body’s ability to absorb fat.
Who Is Eligible for GLP-1s?
The FDA has approved GLP-1 medications for weight management in adults who have:
- a BMI of ≥ 30 kg/m² or
- a BMI of ≥ 27 kg/m² and one or more of the following comorbid conditions associated with overweight/obesity:
- type 2 Diabetes
- hypertension
- dyslipidemia
- obstructive sleep apnea
These medications are not recommended for:
- Pregnant and breastfeeding women
- People with a personal or familial history of Medullary Thyroid Carcinoma
- People with Multiple Endocrine Neoplasia Syndrome Type 2
These lists of eligibility criteria and contraindications are not extensive. It is important to seek medical advice before starting GLP-1 medications to determine if you are eligible and to make sure you can use it safely.
Effectiveness: What Results Can You Expect?
Clinical trials show 1.7 mg or 2.4 mg of semaglutide can result in 12% to 15% body weight loss, with some patients losing up to 20% in 3 to 6 months. Tirzepatide has led to greater weight loss, ranging from 15% to 22%. While weight loss can be noticeable quickly, individual responses and results vary based on initial weight, dosage, lifestyle, and metabolic state. In addition to weight loss, GLP-1s can reduce blood sugar, cholesterol, and hypertension. Weight regain is likely if a healthy lifestyle is not maintained after stopping medication.
Note that while GLP-1 medications can reduce hunger and make it easier to control food portions, they don’t guarantee a sufficient nutrient intake and muscle preservation. It’s important to exercise, eat whole foods, improve sleep quality, and maintain mental well-being around food for long-term success.
Side Effects and Risks
GLP-1 receptor agonists can cause side effects. The most common side effects usually happen when starting the medication or when the dose is increased. The side effects that are commonly experienced include:
- Nausea
- Vomiting
- Diarrhea
- Constipation
- Bloating
- Loss of appetite
- Fatigue
- Headache
In some instances, there are potential side effects that are more serious, and these include:
- Pancreatitis
- Gallbladder problems
- Kidney problems usually related to dehydration
- Possible thyroid C-cell cancer
Due to these potential side effects, GLP-1 medications should always be used under the care and guidance of a medical professional.
What Happens When You Stop Taking GLP-1s?
Research has shown that if a patient stops taking GLP-1 medications, they are likely to notice an increase in body weight over time, especially if they stop eating a balanced diet and exercise regularly. Although not necessary for everyone, many medical providers consider GLP-1 therapy for long-term treatment. During this time, it’s important to:
- Emphasize protein intake, build and maintain muscle mass through strength training, develop structured eating habits, improve sleep and stress management, and monitor health regularly.
- Establish psychological support to understand that some weight gain after stopping treatment is a biological process rather than a failure.
Alternatives to GLP-1s
If the individual does not qualify for GLP-1 therapy or simply wants other options, alternatives include:
- Other weight loss medications, if appropriate.
- Bariatric surgery.
- Intensive behavioral therapy.
- Lifestyle-based weight management strategies, such as:
- Personalized nutrition plans
- Exercise
- Improving sleep quality
Conclusion
GLP-1 medications address the hormonal and metabolic causes of obesity. However, they are not the ideal choice for everyone. The selection of the appropriate medication depends on individual health history, goals, medication’s side effects and contraindications, insurance coverage, and personal preferences.
If you are thinking of using GLP-1 therapy, it is important to note that they still require effort and dedication on your part. Consult a qualified medical practitioner to formulate a plan according to your health requirements.
