Tenuate and Phentermine

A Comparison of Tenuate and Phentermine

It can be hard to understand the difference between weight loss medications, especially if you are trying to choose between two stimulant medications such as Tenuate and phentermine.

As part of our series of drug comparison articles, we will compare Tenuate vs. phentermine to help you find the right drug for your individual circumstances.

What Is Tenuate?

Tenuate is a stimulant prescription weight loss medication that shares some properties with amphetamine. Its active ingredient, diethylpropion, rouses the central nervous system to increase the heart rate and blood pressure.

It also works as an appetite suppressant. Tenuate is suitable for adults with a body mass index (BMI) of 30 or higher if weight loss has not been achieved through diet and exercise alone. (1)

There are two types of Tenuate. The immediate-release version of Tenuate contains 25mg of diethylpropion and is commonly taken three times daily one hour before meals. Conversely, Tenuate Dospan, or Tenuate 75mg, is an extended-release medication that only needs to be taken once in the mid-morning. (1)

In a study, clinically significant weight loss was noted in participants who followed a hypocaloric diet and took diethylpropion for 6 months. The average weight loss at 6 months was 9.8% of baseline weight. Another study showed that, on average, participants lost 11.6 lbs after 12 weeks. (2) (3)

What Is Phentermine?

Phentermine is also a stimulant weight loss drug. Phentermine raises the heart rate and blood pressure. It can make you feel that you have more energy but a smaller appetite, making it easier to lose weight. Phentermine is a generic pill that contains phentermine hydrochloride.

However, it is also marketed under the brand names Adipex-P and Lomaira. (4)

In clinical trials of phentermine, around half of the participants lost at least 10% of their baseline body weight in 3 months. The researchers also saw improvements in waist circumference, cholesterol levels, and blood pressure. (5)

Tenuate vs. Phentermine Side-by-Side Comparison

When comparing the two appetite suppressants, it’s common to ask whether Tenuate is the same as phentermine. Although both weight loss medications share structural similarities with amphetamine, they are different compounds.

Our comparison table makes it easier to see at a glance the variations between the medications, as well as specific drug interactions or contraindications to their use.

Which Is Safer: Phentermine or Tenuate?

A clinical study directly compared Tenuate Dospan vs. phentermine. Regardless of which medication was taken, the incidence of side effects was comparable.

With both drugs, the side effects were found to be mild. Tenuate and phentermine are, therefore, likely to have a similar safety profile. (12)

Can I Take Phentermine and Tenuate Together?

Take Tenuate and Phentermine

No. Taking phentermine and Tenuate together is contraindicated as it is associated with pulmonary hypertension, a condition that can be fatal. Taking two weight loss drugs at the same time may also increase the risk of side effects. (1)

Tenuate vs. Phentermine – Which One Is Better for Me?

The best diet pill will depend on your personal circumstances. Both Tenuate and phentermine are available as generic pills, but phentermine tends to be a more affordable option.

However, the cost may be less important if your medical insurance covers a course of treatment.

Both phentermine and Tenuate Dospan only need to be taken once daily, but standard release Tenuate is usually taken three times daily. If you take another medication already, it is important to check for drug interactions that could occur.

You may be wondering what works better, Tenuate or phentermine? A clinical trial that compared the two drugs head-to-head found that although the two weight loss drugs had a similar safety profile, there was significantly greater weight loss in patients who were treated with phentermine rather than Tenuate. (12)

With this research in mind, some people may feel that phentermine could be a better option for weight loss. However, prior to deciding it is important to discuss your options with a healthcare professional.

Make sure to consult as well our analysis of the other prescription weight loss drugs currently available in the United States.


1. US FDA (Tenuate).
2. Cercato C. et al. A randomized double-blind placebo-controlled study of the long-term efficacy and safety of diethylpropion in the treatment of obese subjects. International Journal of Obesity. 2009; 33: 857-865.
3. Murphy JE. et al. A Comparison of Mazindol (Teronac) with Diethylpropion in the Treatment of Exogenous Obesity. Journal of International Medical Research. 1975; 3 (3): 202-206.
4. Phentermine.com (Phentermine).
5. Kim, KK et al. Effects on weight reduction and safety of short-term phentermine administration in Korean obese people. Yonsei Medical Journal. 2006; 47: 614-625.
6. Phentermine.com (Phentermine Dosage).
7. Phentermine.com (Phentermine Side Effects).
8. RxList.com (Tenuate Side Effects).
9. Phentermine.com (Phentermine Warnings).
10. BlinkHealth.com (Buy Phentermine).
11. BlinkHealth.com (Buy Generic Tenuate).
12. Valle-Jones JC et al. A comparative study of phentermine and diethylpropion in the treatment of obese patients in general practice. Pharmatherapeutica. 1983; 3 (5): 300-304.