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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)

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Phentermine

(Adipex-P)

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Summary for Wegovy

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.

Indications for Wegovy

Injectable pens:

Tablets:

Pros and Cons for Wegovy

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

Common Side Effects for Wegovy

  • Nausea (44%)
  • Diarrhea (30%)
  • Vomiting (24%)
  • Constipation (24%)
  • Stomach pain (20%)
  • Headache (14%)
  • Tiredness (11%)

Warnings for Wegovy

  • 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
  • Lung problems during general anesthesia or deep sedation

Summary for Phentermine

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 for Phentermine

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

Pros and Cons for Phentermine

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 for Phentermine

  • Dry mouth
  • Headache
  • Tremor
  • Constipation
  • Diarrhea
  • High blood pressure
  • Fast heart rate
  • Difficulty sleeping

Warnings for Phentermine

  • 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

Price Card Drug Icon
Wegovy30 tablets / 1.5mg
$149.00-
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Phentermine30 tablets / 37.5mg
$12.05-
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