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Compare Orlistat vs. Phentermine

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

  • Orlistat
    Phentermine (Adipex-P)
  • Orlistat
    Phentermine (Adipex-P)

  • Summary of Orlistat vs. Phentermine

    Summary for Lipase inhibitor

    Orlistat is a medication that works alongside diet and exercise to increase weight loss in people who are overweight or obese. It needs to be taken three times a day and is available with a prescription in a higher dose (Xenical) or over the counter in a lower dose (Alli).

    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 Orlistat vs. Phentermine

    Indications for

    Xenical (orlistat):

    Obesty management in adults with a body mass index (BMI) of:

    •30 kg/m^2^ or greater or
    •27 kg/m^2^ or greater and at least one weight-related condition (e.g., high blood pressure, type 2 diabetes, or high cholesterol)

    Alli (orlistat):

    Weight loss in adults when combined with a lower-calorie and low-fat diet

    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 Orlistat vs. Phentermine

    Pros and Const for Lipase inhibitor
    Pros
    •Works well to block a portion of the fat you eat
    •Xenical is approved for people ages 12 years and older.
    •Available in both prescription and over-the-counter forms
    Cons
    •Still need to maintain a healthy diet and exercise routine
    •Must remember to take with each fat-containing meal
    •Only available as a brand medication so it can be expensive
    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 Orlistat vs. Phentermine

    Common Side Effects for

    Xenical (orlistat):

    •Oily spotting on underwear (4-27%)
    •Gas with anal discharge (2-24%)
    •Urge to have a bowel movement (3-22%)
    •Fatty or oily stool (6-20%)
    •Having more bowel movements (3-11%)
    •Difficulty controlling bowel movements (2-8%)

    Alli (orlistat):

    •Gas with oily spotting
    •Loose stools
    •More frequent stools that are hard to control
    Common Side Effects for
    •Dry mouth
    •Headache
    •Tremor
    •Constipation
    •Diarrhea
    •High blood pressure
    •Fast heart rate
    •Difficulty sleeping

  • Warnings of Orlistat vs. Phentermine

    Common Side Effects for
    •Medication interactions
    •Liver injury
    •Higher oxalate levels in the urine
    •Gallstones
    •Other causes of obesity
    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 Orlistat vs. Phentermine

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    Learn more about Phentermine

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