Which agent is not approved for weight management because of its relatively low efficacy?

• A. Orlistat
• B. Phentermine
• C. Liraglutide
• D. Lisdexamfetamine

Answer: (D)

The key idea is that weight-management medications must show meaningful, sustained weight loss with acceptable safety to gain approval for obesity treatment. Lisdexamfetamine is a stimulant that can affect appetite, but when looked at for obesity, the weight loss it produces is relatively small and not consistently clinically meaningful. Safety concerns, including potential for misuse and cardiovascular or psychiatric effects with long-term use, further limit its suitability for chronic weight management. Because of this combination of limited efficacy and safety considerations, it isn’t approved as a weight-management therapy, unlike other agents such as orlistat (which reduces fat absorption), phentermine (short-term appetite suppression with modest loss), and liraglutide (a GLP-1 receptor agonist with demonstrated longer-term weight loss).