What is the Difference Between Blue & Yellow Phentermine?

Phentermine is a medication that is prescribed for weight loss and management. It serves as an appetite suppressant and is recommended for use with a low-calorie diet and exercise, reports the National Center for Biotechnology Information. Phentermine is known by several brand names.

Active Ingredient

• Phentermine is also known as phentermine hydrochloride, according to the Merck Manuals Online Medical Library. The active chemicals in phentermine stimulate the body's hypothalamus gland, which in turn affects neurotransmitters that decrease appetite, reports a writer on Phentermine.com.

Forms

• Phentermine is made available commercially in three different forms: tablets, capsules and resin capsules. Each of the versions has a different time-release factor.

Colors

• Almost all forms of phentermine are packaged with some blue or yellow coloring, but also include black, white and gray. The colors do not indicate any significant difference, though the various forms of phentermine do contain differing amounts of the medication's active ingredient and should be used strictly according to prescribed dosage.