Which prescription drug is an example of a controlled substance designed for weight loss?

Adipex, also known by its generic name phentermine, is a medication specifically indicated for weight management and is classified as a controlled substance due to its potential for abuse and dependence. It functions as an appetite suppressant and is typically prescribed as part of a comprehensive weight loss program that includes diet and exercise.

Phentermine stimulates the central nervous system, leading to an increase in heart rate and blood pressure, which can help reduce hunger and promote weight loss in patients who are obese or overweight. The classification of phentermine as a Schedule IV controlled substance reflects the regulatory recognition of its potential for misuse, especially in the context of weight loss.

The other options listed do not serve the purpose of weight loss. For instance, Tylenol #3 (acetaminophen with codeine) is primarily used for pain relief, Ultram (tramadol) is an analgesic for moderate to severe pain, and Skelaxin (metaxalone) is a muscle relaxant used for treating muscle spasms. These medications may have their own therapeutic uses but are not intended for weight management.