From the Guidelines
The most effective FDA-approved weight loss medications currently available include semaglutide (Wegovy), tirzepatide (Zepbound), liraglutide (Saxenda), phentermine-topiramate (Qsymia), naltrexone-bupropion (Contrave), and orlistat (Xenical, Alli), with Wegovy and Zepbound showing the most significant results, achieving an average weight loss of 15-20% of body weight over 68 weeks, as reported in the most recent study 1.
Key Considerations for Weight Loss Medications
- The choice of medication should be based on individual patient needs, including the presence of comorbidities, potential side effects, and cost considerations.
- Medications should be used in conjunction with a comprehensive weight loss program, including diet and exercise, to achieve optimal results.
- Regular monitoring of efficacy and safety is crucial, with adjustments to the treatment plan as needed.
Mechanisms of Action
- GLP-1 receptor agonists, such as semaglutide and liraglutide, regulate appetite and slow stomach emptying.
- Phentermine-topiramate and naltrexone-bupropion affect neurotransmitters involved in hunger and satiety.
- Orlistat inhibits fat absorption in the gastrointestinal tract.
Patient Selection
- Medications are approved for adults with a BMI ≥30 or BMI ≥27 with weight-related conditions, such as hypertension or type 2 diabetes.
- Insurance coverage varies, and long-term use is often necessary to maintain weight loss.
Recent Developments
- Tirzepatide, a novel co-agonist of GLP-1 and glucose-dependent insulinotropic polypeptide receptors, has shown promising results in clinical trials, with mean weight loss of 21% after 72 weeks of treatment, as reported in a recent study 1.
- Further research is needed to fully understand the efficacy and safety of these medications, particularly in diverse patient populations.
From the FDA Drug Label
The safety and efficacy of combination therapy with phentermine and any other drug products for weight loss including prescribed drugs, over-the-counter preparations, and herbal products, or serotonergic agents such as selective serotonin reuptake inhibitors (e.g., fluoxetine, sertraline, fluvoxamine, paroxetine), have not been established. Phentermine is indicated only as short-term (a few weeks) monotherapy for the management of exogenous obesity
FDA approved weight loss medication is phentermine (PO) and semaglutide (SQ).
- Phentermine (PO) is indicated only as short-term (a few weeks) monotherapy for the management of exogenous obesity.
- Semaglutide (SQ) is approved for weight loss, as shown by significant reductions in body weight in clinical trials 2.
From the Research
FDA Approved Weight Loss Medications
The following medications are approved by the FDA for weight loss:
- Orlistat 3, 4, 5, 6
- Phentermine/topiramate 3, 7, 6
- Naltrexone/bupropion 3, 7, 6
- Liraglutide 3, 7, 6
- Semaglutide 3, 7
- Metreleptin and Setmelanotide are approved for rare obesity syndromes 3
- Tirzepatide is expected to be approved soon 3, 7
Mechanism of Action
These medications work by:
- Reducing appetite and increasing satiety 3
- Slowing gastric emptying 3
- Inhibiting absorption of dietary fat (orlistat) 4, 5
- Acting on the GLP-1 receptor (semaglutide, liraglutide) 7
Efficacy and Safety
The medications have been shown to:
- Improve weight and metabolic parameters 3
- Produce variable potency and effects depending on the specific drug 3
- Have a good safety profile, with gastrointestinal adverse events being most commonly reported (orlistat) 4, 5
- Be cost-effective in patients with obesity, particularly those with type 2 diabetes (orlistat) 5