HomePhentermine FAQsWhat is the difference between phentermine and Phen Caps?What is the difference between phentermine and Phen Caps?Phentermine is a prescription-only weight loss medication. It contains the active ingredient phentermine HCL, which is considered a controlled substance. The intended effects of phentermine are appetite suppression and energy enhancement, but most users also experience at least one side effect.Phen Caps is an all-natural weight loss supplement. It is available online and without a prescription because it does not contain phentermine HCL (or any other controlled substance). It helps suppress appetite and boost energy, and does not cause any adverse side effects.→ Click here to read more about Phen Caps!