Despite a recent decline in U.S. adult obesity rates – from 39.9% in 2022 to 37% in 2025 – the demand for effective obesity treatments remains significant. While lifestyle changes like diet and exercise are fundamental, they often prove insufficient for long-term weight management. Medications can help bridge this gap by addressing the biological factors that drive weight gain, as explained by Dr. Timothy Garvey of the University of Alabama at Birmingham: “Obesity is a lifelong disease that requires lifelong intervention… medications can stop the processes that cause this weight gain.”
Currently, weight loss medications are approved for adults with a BMI of 30 or higher, or for those with a BMI of 27 or higher who also have weight-related health problems such as high blood pressure, diabetes, or sleep apnea. However, the path to safe and effective treatments has been fraught with setbacks.
A History of Risks and Recalls
The early days of weight loss drugs were marked by dangerous experimentation. As far back as the 1940s, “rainbow pills” – cocktails of amphetamines, diuretics, laxatives, and thyroid hormones – were aggressively marketed, often with fatal consequences. By the 1960s, the FDA pulled these unregulated mixtures off the market after numerous deaths. Dr. Frank Greenway of Louisiana State University emphasizes the issue: “None of these medications were tested in long-term trials… this raises the risk that they will have side effects not recognized in short-term therapy.”
The 1990s saw the rise and fall of “fen-phen,” a combination of fenfluramine and phentermine, which was later recalled due to heart valve defects. Subsequent drugs like sibutramine (Meridia) and lorcaserin (Belviq) also faced recalls over cardiovascular risks and cancer concerns, respectively. These failures underscored the need for more rigorous testing.
Modern Oversight and New Options
In the late 1990s, the FDA implemented stricter clinical trial requirements for obesity drugs. Today’s approved medications have undergone more extensive testing and generally offer a better safety profile. Several options are now available, each with its own mechanism and considerations:
- Tirzepatide (Zepbound): A weekly injection mimicking hormones that regulate insulin and digestion, showing an average weight loss of 22.5% in clinical trials. Common side effects include nausea, diarrhea, and vomiting.
- Semaglutide (Wegovy): Another GLP-1 receptor agonist, available as a weekly injection or a daily oral pill. It regulates appetite and has been linked to thyroid tumors in animal studies.
- Naltrexone-Bupropion (Contrave): An oral drug combining addiction and depression treatments to suppress appetite. It may increase suicidal thoughts and should be avoided by those with uncontrolled blood pressure.
- Liraglutide (Saxenda): A daily injection mimicking appetite-regulating hormones. It carries a risk of pancreatitis and has been linked to thyroid tumors in animals.
- Phentermine-Topiramate (Qsymia): A pill suppressing appetite. It should not be used by those with glaucoma, hyperthyroidism, or a history of heart problems.
- Orlistat (Xenical, Alli): A pill blocking fat absorption, causing diarrhea, gas, and oily stool leakage. It can interfere with nutrient absorption and certain medications.
Weighing the Benefits and Risks
Before starting weight loss medication, patients should discuss potential risks and side effects with their healthcare provider. These drugs should not be used during pregnancy or by individuals with eating disorders. Lifestyle changes – including diet, exercise, and regular check-ups with an obesity specialist – remain crucial for long-term success.
The current generation of weight loss drugs represents a significant step forward in safety and efficacy. However, responsible use and informed decision-making are essential to maximize benefits while minimizing harm.
Conclusion: Modern obesity treatments offer a valuable tool for those struggling with weight management, but they are not a replacement for lifestyle interventions. As research advances and regulations tighten, the future of weight loss medication holds promise for safer, more effective solutions.
