Understanding Weight Loss Medications: What You Need to Know

Recent statistics show that approximately 73% of American adults are classified as overweight or living with obesity, and nearly half are actively working toward weight loss. Shedding extra pounds and maintaining a healthier weight can be challenging. Adopting nutritious habits and sticking with them over time often proves difficult. This article is intended to help readers understand weight Loss Medications.

Incorporating more nutrient-dense foods and increasing daily physical activity supports both physical and mental well-being. Losing even 5–10% of body weight can have positive effects, including reductions in triglycerides, blood pressure, and blood sugar levels. Still, for many individuals, lifestyle changes alone might not be enough, and further interventions may be necessary.

The Role of Prescription Weight Loss Medications

For individuals seeking additional support, there are several FDA-approved medications designed for long-term weight management. Referred to as anti-obesity medications (AOMs), these treatments are intended to complement—not replace—healthy eating and regular exercise. On their own, these medications offer limited results, but when used alongside lifestyle changes, they can enhance weight loss outcomes.

These prescriptions are typically recommended for individuals with a BMI of 30 or higher, or a BMI of 27 or more if accompanied by health concerns such as hypertension or type 2 diabetes. A physician’s evaluation is essential to determine eligibility and select the most appropriate medication.

How These Medications Work

Weight loss medications function in different ways to support appetite control and reduce food cravings. They influence hormones and chemical messengers like GLP-1, ghrelin, and serotonin, which regulate hunger and satiety signals in the brain, digestive system, and fat tissue. As a result, individuals often feel full sooner, experience fewer cravings, and consume fewer calories overall.

One exception is orlistat, which doesn’t affect appetite but instead prevents the body from absorbing some of the fat consumed during meals.

Common Anti-Obesity Medications

Semaglutide, Tirzepatide, and Liraglutide

Semaglutide and tirzepatide are injectable treatments administered weekly. These medications work on receptors. Semaglutide acts on GLP-1 receptors, while tirzepatide targets both GLP-1 and GIP receptors. Both medications help regulate appetite through brain signaling. Dosages begin low and increase gradually to help reduce side effects such as digestive discomfort, dizziness, and fatigue.

Liraglutide is another injectable, taken daily, that similarly works on gut hormones to promote fullness and decrease hunger.

Naltrexone-Bupropion

This oral medication combines two components: one that influences mood and cravings, and another that blocks reward pathways associated with food and substance use. Together, they reduce appetite and emotional eating.

Phentermine and Phentermine-Topiramate

Phentermine is one of the oldest weight loss medications and acts as an appetite suppressant. When paired with topiramate, a medication used for migraines and seizures, it also helps decrease cravings and promote satiety.

Orlistat

Available in both prescription and lower-dose over-the-counter versions, orlistat works by blocking enzymes that digest dietary fat. This leads to a reduction in fat absorption—up to 30%—and promotes calorie loss through digestion. Because fat is excreted rather than absorbed, some users experience gastrointestinal side effects such as gas, loose stools, or abdominal discomfort.

Setmelanotide

Setmelanotide is a daily injection approved for individuals with specific rare genetic disorders affecting weight regulation, such as POMC or leptin receptor deficiencies. While it doesn’t cure these conditions, it helps manage appetite, enhances feelings of fullness, and supports energy expenditure.

Side Effects and Considerations

Like any medication, weight loss drugs come with potential side effects. The most common are mild digestive issues—nausea, constipation, or diarrhea—but some individuals may experience headaches, dry mouth, insomnia, or fatigue. Most side effects improve over time, but ongoing communication with your healthcare provider is crucial.

For those taking orlistat, side effects are often related to fat passing through the digestive system. Eating a lower-fat diet can help minimize discomfort. It’s also worth noting that some weight may return after discontinuing medication—a normal physiological response tied to hormonal and metabolic changes. Maintaining healthy habits can help mitigate this rebound.

Nutrition Tips for Individuals Using Weight Loss Medications

A healthy eating plan remains essential while using any anti-obesity medication. Key elements of a sustainable weight loss strategy include:

• Setting realistic weight goals—such as losing one pound per week
• Eating more fiber-rich foods like vegetables, fruits, and whole grains
• Choosing lean proteins and low-fat dairy products
• Reducing processed, high-sugar, or high-sodium foods
• Watching portion sizes
• Prioritizing water as your main beverage
• Staying physically active on a consistent basis

If you’re taking orlistat, it’s especially important to talk to your healthcare provider about whether you should take a multivitamin, as the medication can limit the absorption of fat-soluble vitamins.

Final Thoughts

As the Mayo Clinic puts it, weight loss medications are not a magic bullet—but they can offer meaningful support when combined with consistent lifestyle efforts. If you’re ready to take the next step toward achieving sustainable weight loss, whether with or without medication, working with a qualified nutrition professional can help you build a personalized plan that fits your needs and goals.

Meal Plans and Support

Are you looking for expert guidance to navigate your weight loss journey? Starts on the Inside offers meal plans created by a registered dietitian that can help you create a realistic, supportive, and science-backed plan to help you feel your best. Ready to start? Choose a plan now.

Note: This article is intended for informational purposes only and does not substitute professional medical advice. Always consult with a healthcare provider for personalized recommendations.

References

1. National Institute of Diabetes and Digestive and Kidney Diseases. (2024, February). Choosing a safe & successful weight-loss program. U.S. Department of Health and Human Services, National Institutes of Health. Retrieved January 14, 2025, from  https://www.niddk.nih.gov/health-information/weight-management/choosing-a-safe-successful-weight-loss-program

2. National Center for Health Statistics. (2018, July 12). Attempts to lose weight among adults in the United States, 2013–2016. Centers for Disease Control and Prevention. Retrieved January 14, 2025, from https://www.cdc.gov/nchs/products/databriefs/db313.htm

3. Mayo Clinic. (2023, November 1). Weight loss basics. Retrieved January 14, 2025, from https://www.mayoclinic.org/healthy-lifestyle/weight-loss/basics/weightloss-basics/hlv-20049483

4. National Institute of Diabetes and Digestive and Kidney Diseases. (2024, June). Prescription medications to treat overweight & obesity. U.S. Department of Health and Human Services, National Institutes of Health. Retrieved January 14, 2025, from https://www.niddk.nih.gov/health-information/weight-management/prescription-medications-treat-overweight-obesity

5. Obesity Medicine Association. (2024, January 26). Top weight loss medications. Retrieved January 14, 2025, from  https://obesitymedicine.org/blog/weight-loss-medications/

6. Cleveland CliniTop Weight Loss Medications | Obesity Medicine Associationc. (2023, November 20). Appetite suppressants. Retrieved January 14, 2025, from https://my.clevelandclinic.org/health/treatments/9463-appetite-suppressants

7. Mayo Clinic. (2022, October 29). Prescription weight-loss drugs. Retrieved January 14, 2025, from https://www.mayoclinic.org/healthy-lifestyle/weight-loss/in-depth/weight-loss-drugs/art-20044832

8. Medline Plus. (2023, July 8). Weight-loss medicines. U.S. Department of Health and Human Services, National Institutes of Health. Retrieved January 14, 2025, from https://medlineplus.gov/ency/patientinstructions/000346.htm

Johns Hopkins Medicine. (n.d.). Medical nutrition therapy for weight loss. Retrieved January 14, 2025, from https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/medical-nutrition-therapy-for-weight-loss