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Compare Saxenda vs. Phentermine

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

Key takeaways

Liraglutide (Saxenda) and phentermine (Adipex-P) are both medications used to help with weight loss, but they belong to different medication classes and work in different ways. Liraglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist that helps control appetite by slowing down your gut, making you feel less hungry. It is injected under the skin once daily. Phentermine, on the other hand, is a sympathomimetic stimulant that suppresses appetite and is taken orally, usually once a day in the morning. While both medications are used for weight management, liraglutide is approved for use in adults and children over 12 with a high body mass index (BMI). Phentermine is only approved for short-term use in people who are 17 years of age and older. Liraglutide is not a controlled substance, but phentermine is a Schedule IV controlled substance due to its potential for misuse and dependence. Common side effects of liraglutide include nausea, vomiting, and diarrhea, while phentermine can cause dry mouth and trouble sleeping. Additionally, you should avoid combining either medication with other weight loss medications.

  • Saxenda (liraglutide)
    Phentermine (Adipex-P)
  • Saxenda (liraglutide)
    Phentermine (Adipex-P)

  • Summary of Saxenda vs. Phentermine

    Summary for GLP-1 agonist
    Prescription only

    Saxenda (generic name liraglutide) is a once-daily injection given under the skin that's used for weight loss. It's approved for certain adults and children ages 12 years and up. And it works best when used along with a balanced diet and exercise. This prescription weight loss medication is a glucagon-like peptide-1 (GLP-1) agonist. It works by slowing down your gut and making you feel less hungry. Saxenda (liraglutide) comes as a prefilled pen you use to inject your dose. Some common side effects include nausea, vomiting, and diarrhea.

    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 Saxenda vs. Phentermine

    Indications for
    •Weight loss and long-term weight management in:
    •People ages 12 years and older with a body weight greater than 132 lbs and obesity
    •Adults who are considered overweight with at least one weight-related condition (e.g., high blood pressure, Type 2 diabetes, high cholesterol)
    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 Saxenda vs. Phentermine

    Pros and Const for GLP-1 agonist
    Pros
    •Can help you lose weight in addition to balanced nutrition and exercise
    •Can take with or without food, at any time during the day
    •Okay for children 12 years of age and older weighing more than 132 lbs with obesity
    Cons
    •Must inject once a day
    •Can cause stomach upset
    •Doesn't come with pen needles (must get them separately)
    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 Saxenda vs. Phentermine

    Common Side Effects for

    Adults:

    •Nausea (39%)
    •Diarrhea (21%)
    •Constipation (19%)
    •Vomiting (16%)
    •Injection site reaction (e.g., redness, itching, rash; 14%)
    •Headache (14%)
    •Low blood sugar in people with Type 2 diabetes (13%)
    •Indigestion (10%)

    Children 12 years and up:

    •Nausea (42%)
    •Vomiting (34%)
    •Diarrhea (22%)
    •Low blood sugar (15%)
    •Stomach inflammation (13%)
    •Dizziness (10%)
    Common Side Effects for
    •Dry mouth
    •Headache
    •Tremor
    •Constipation
    •Diarrhea
    •High blood pressure
    •Fast heart rate
    •Difficulty sleeping

  • Warnings of Saxenda vs. Phentermine

    Common Side Effects for
    •Possible risk for thyroid cancer
    •Inflammation of the pancreas (pancreatitis)
    •Gallbladder problems
    •Low blood sugar
    •Faster heart rate
    •Severe stomach side effects
    •Kidney problems due to dehydration
    •Allergic reactions
    •Lung problems during 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 Saxenda vs. Phentermine

    Learn more about Saxenda
    Learn more about Phentermine

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