Kinds of Phentermine

Phentermine is a generic, or chemical, name for this medicine. You can buy the generic form or you can also buy one of the brand forms from three different drug companies.

• Ionamin® (yellow 30 mg resin capsule or yellow/grey 15 mg capsule) is a form of Phentermine that is set in resin. The resin causes it to release slowly into your body. Slower release may mean that it has less side effects, but some people don’t think it works quite as well as other forms of Phentermine. Ionamin, made by Medeva Pharmaceuticals, comes in two forms. One form is 30 mg capsules, which are yellow. Another is 15 mg capsules, which are grey and yellow. Both capsules have the name “Ionamin” printed on them. They usually come in either a 1-month (30 capsules) or 3-month (90 capsules) supply.
• Adipex-P® (blue/white 37.5 capsule or oblong, white, scored 37.5 mg tablet) is the most common brand form of Phentermine. It’s made by Gate Pharmaceuticals. It comes in both an oblong, white, scored tablet or a blue and white capsule containing 37.5 mg that has the name printed on it. You can buy it in 1-month (30 pills) and 3-month (90 pills) supplies.
• Generic forms (yellow/grey 15 mg capsule, blue/white 30 mg capsule or white 37.5 mg tablet) are also available from Eon Labs. They come in yellow and grey, 15 mg capsules and blue and white, 30 mg capsules. Purepac also makes 37.5, white oblong tablets. All of the generics come in 30-day, 60-day or 90-day supplies.

You may also have heard of Fastin®, but this brand was taken off the market in the US several years ago. Phentermine is sometimes used in a combination “cocktail” with antidepressants such as Prozac, Zoloft, Celexa, Luvox, Trazadone or Effexor. Taken this way, Phentermine works better and the effects last longer.

How Do I Find the Right Dose?

To be safe, prescription medicine should be taken exactly as directed by your doctor. Your doctor can figure out which dose is right for you based on your BMI and current weight, your medical history, your weight loss goals and other factors. Most doctors will start with the lowest dose possible. Then if the lower dose doesn’t produce the desired effect, they’ll move you up to a higher dose. Adipex-P has become well-liked because it offers a timed-release tablet that often has fewer side effects. The key step is that you keep the doctor informed about how you’re reacting to this medicine after you start taking it.