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Compare Phentermine vs. Benzphetamine

Head-to-head comparisons of medication uses, side effects, warnings, and more.

Key takeaways

Phentermine (Adipex-P) and benzphetamine are both sympathomimetic medications used for short-term weight management in adults with a body mass index (BMI) of 30 kg/m² or greater. They both work by suppressing appetite and are controlled substances, due to their risk to lead to misuse and dependence. Phentermine is available as a brand and a lower-cost generic and comes in various forms, including tablets, capsules, and orally disintegrating tablets. It is typically taken once daily in the morning. Benzphetamine is only available as a generic tablet and can be taken one to three times per day. Both medications can cause side effects like high blood pressure and trouble sleeping, but phentermine may be more likely to cause dry mouth and headache, while benzphetamine can lead to a bad taste in your mouth. Both medications should not be combined with other weight loss medications.

  • Phentermine (Adipex-P)
    Benzphetamine
  • Phentermine (Adipex-P)
    Benzphetamine

  • Summary of Phentermine vs. Benzphetamine

    Summary for Sympathomimetic
    Prescription only

    Phentermine (Adipex-P) is an appetite suppressant. It's a prescription weight loss pill for people ages 17 years and older. This medication works best when it's part of a treatment plan that involves healthy diet and regular exercise. Phentermine (Adipex-P) is taken by mouth once daily, typically in the morning. Some of the more common side effects of this medication include dry mouth, trouble sleeping, and headache.

    Summary for Sympathomimetic amine
    Prescription only

    Benzphetamine, formerly known by its brand name Didrex, is a prescription appetite suppressant that's used with diet and exercise to help adults with weight loss. It's classified as a sympathomimetic medication and is also a Schedule III controlled substance. Benzphetamine is currently available only as a generic tablet that's taken by mouth once per day. Side effects include high blood pressure, trouble sleeping, and restlessness.

  • Indications of Phentermine vs. Benzphetamine

    Indications for

    Short-term treatment for weight management in adults with a body mass index (BMI) of:

    •30 kg/m2 or greater; or
    •27 kg/m2 or greater, and with at least one other weight-related condition (e.g., high blood pressure, high blood sugar, high cholesterol)
    Indications for

    Short-term treatment for weight management in adults with a body mass index (BMI) of 30 kg/m2 or greater

  • Pros and Cons of Phentermine vs. Benzphetamine

    Pros and Const for Sympathomimetic
    Pros
    •Can help you lose 5% to 10% of body weight
    •Usually taken by mouth once per day
    •Available as a lower-cost generic
    •Comes as tablets, capsules, and orally disintegrating tablets
    Cons
    •Most insurance companies don't cover the cost of phentermine (Adipex-P).
    •Has a risk of misuse and dependence since it's a stimulant medication that's similar to amphetamines
    •Might not be a good choice for people with high blood pressure
    •Should be avoided in children 16 years of age and younger, pregnant and breastfeeding women, and people with serious heart problems
    Pros and Const for Sympathomimetic amine
    Pros
    •Taken by mouth once per day
    •Available as a lower-cost generic medication
    Cons
    •Risk of misuse and dependency
    •Doesn't have a lot of clinical evidence or experience

  • Common Side Effects of Phentermine vs. Benzphetamine

    Common Side Effects for
    •Dry mouth
    •Headache
    •Tremor
    •Constipation
    •Diarrhea
    •High blood pressure
    •Fast heart rate
    •Difficulty sleeping
    Common Side Effects for
    •Fast heartbeat
    •High blood pressure
    •Feeling overstimulated
    •Restlessness or shakiness
    •Dizziness
    •Trouble sleeping
    •Sweating

  • Warnings of Phentermine vs. Benzphetamine

    Common Side Effects for
    •Not safe to combined with other weight loss medications
    •Phentermine not working well
    •Risk of misuse and dependence
    •Trouble concentrating or problem with coordination
    •Heart and lung problems
    •Risk of high blood pressure
    •Risk of low blood sugar in people with diabetes
    Common Side Effects for
    •Not safe with other weight loss medications
    •Lower response to the medication over time
    •Risk of misuse and dependence
    •High blood pressure in the lungs (pulmonary hypertension)
    •Heart valve problem
    •Risk of high blood pressure
    •Risk of low blood sugar in people with diabetes

  • Prices with our coupons for Phentermine vs. Benzphetamine

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