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Compare Wegovy vs. Phentermine

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

Key takeaways

Semaglutide (Wegovy) and phentermine (Adipex-P) are both prescription weight management medications, but they have important differences. Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist, while phentermine is a sympathomimetic stimulant. Semaglutide is FDA-approved for long-term weight management in adults and children aged 12 and older meeting certain body mass index (BMI) criteria. It also lowers the risk of heart problems in adults with heart disease. Phentermine, on the other hand, is approved for short-term weight management in adults aged 17 and older. Semaglutide is administered as a weekly subcutaneous injection, whereas phentermine is taken orally once daily. Phentermine is available in various forms, including tablets, capsules, and orally disintegrating tablets, and is available as a lower-cost generic. Common side effects of semaglutide include nausea and diarrhea, while phentermine may cause dry mouth, a fast heart rate, and trouble sleeping. Phentermine is a controlled substance due to its potential for misuse and dependence, but semaglutide is not.

  • Wegovy (semaglutide)
    Phentermine (Adipex-P)
  • Wegovy (semaglutide)
    Phentermine (Adipex-P)

  • Summary of Wegovy vs. Phentermine

    Summary for GLP-1 agonist
    Prescription only

    Wegovy (semaglutide) is a glucagon-like peptide-1 (GLP-1) receptor agonist. It comes in prefilled pens you use to inject the medication under the skin once a week. Wegovy (semaglutide) also comes as tablets that are swallowed once a day. This medication is approved for weight loss in some people. It can help lower the risk of heart attack, stroke, and death due to heart problems in adults with a larger body size and heart disease. The pens are also approved for certain adults with a liver problem called metabolic dysfunction-associated steatohepatitis (MASH). The medication works best when taken with a lower-calorie diet and regular exercise. Side effects include nausea, diarrhea, and stomach pain.

    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.

  • Indications of Wegovy vs. Phentermine

    Indications for

    Injectable pens:

    •

    Weight loss and long-term weight management in:

    •People ages 12 years and older who are considered obese
    •Adults considered overweight with at least one weight-related condition (e.g., high blood pressure, Type 2 diabetes, high cholesterol)
    •

    Lowering the risk of heart attack, stroke, and death due to heart problems in adults with a larger body size and heart disease

    •

    Metabolic dysfunction-associated steatohepatitis (MASH) in adults with moderate-to-advanced liver scarring, but not cirrhosis

    Tablets:

    •Weight loss and long-term weight management in adults who are considered obese or overweight with at least one weight-related condition
    •Lowering the risk of heart attack, stroke, and death due to heart problems in adults with a larger body size and heart disease
    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)

  • Pros and Cons of Wegovy vs. Phentermine

    Pros and Const for GLP-1 agonist
    Pros
    •Available as once-weekly injectable pens and as once-daily pills
    •Injectable pens approved for weight loss in children ages 12 years and older considered obese
    Cons
    •Can cause stomach pain, nausea, and diarrhea
    •Can't take with other semaglutide products (Ozempic, Rybelsus) or with other GLP-1 agonists
    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

  • Common Side Effects of Wegovy vs. Phentermine

    Common Side Effects for
    •Nausea (44%)
    •Diarrhea (30%)
    •Vomiting (24%)
    •Constipation (24%)
    •Stomach pain (20%)
    •Headache (14%)
    •Tiredness (11%)
    Common Side Effects for
    •Dry mouth
    •Headache
    •Tremor
    •Constipation
    •Diarrhea
    •High blood pressure
    •Fast heart rate
    •Difficulty sleeping

  • Warnings of Wegovy vs. Phentermine

    Common Side Effects for
    •Possible risk for thyroid cancer
    •Inflammation of the pancreas (pancreatitis)
    •Gallbladder problems
    •Low blood sugar
    •Kidney damage
    •Allergic reactions
    •Eye problems in people with Type 2 diabetes (diabetic retinopathy)
    •Faster heart rate
    •Possible risk of self-harm
    •Lung problems during general anesthesia or deep sedation
    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

  • Prices with our coupons for Wegovy vs. Phentermine

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