Orlistat – The Magic Bullet Pill?

Seunga (Jasmine) Han, PharmD Student

Weight loss, whether it’s for improving appearance or overall well being, is something that many individuals struggle with. Anywhere from the one-food diet, detox diet, to weight loss pills, there are many products and methods out there that claim to support weight loss. Orlistat, a weight loss medication, may sound like an easy way to lose weight, but does it work for everyone? Let’s take a closer look.

Orlistat

Also known as Xenical^® or Alli^®, orlistat is a medication known for its use in weight loss. Unlike many diet pills, orlistat is an FDA (for the US) and Health Canada approved (for Canada) medication for weight loss and/or maintenance with a reduced calorie and fat diet. While it’s available as a prescription medication in Canada, the US also has it available over-the-counter at a lower dose.^1-3

• Xenical^®: 120mg (prescription dose in Canada and the US)
• Alli^®: 60mg (over-the-counter dose in the US)

How Does it Work?

Orlistat works by preventing dietary fat from being broken down into an absorbable form of fat in the body such as fatty acids and monoglycerides. Since these fats cannot be absorbed, your body undergoes a caloric deficit resulting in weight loss, maintenance and prevention of weight regain.^1-3 Taking 120 mg three times a day during or up to one hour after a meal has shown to reduce fat absorption by 30%. Because of it’s mechanism, you don’t need to take the medication if you were to miss a meal or have a meal that doesn’t contain fat.

Does it Work?

Now, this is the million dollar question. Studies show that long-term use (at least 1 year) of orlistat 120 mg three times a day is associated with ≥5% weight loss when combined with diet modification and exercise. However, this clinically significant weight loss ( ≥5% weight loss) was seen in individuals with a BMI ≥30 kg/m² or a BMI ≥27 kg/m² with other risk factors such as high blood pressure, high cholesterol or type 2 diabetes.⁴

Is it Safe?

While the medication is effective in certain populations, there are numerous factors to consider prior to using orlistat. First, there are a number of side effects that are commonly reported with the use of orlistat. These include:^1-3

• Headache
• Fatigue
• Change in sleeping pattern
• Change in menstrual cycle
• Hypoglycemia (low blood sugar levels) in patients with diabetes
• Oily stool and/or leakage/spotting
• Stomach pain
• Flatulence with discharge
• Change in bowel pattern
• URTI, LRTI, UTI

While a balanced diet is important, limiting fat content to approximately 30% of your total calories intake may reduce some of the gastrointestinal side effects mentioned above.

Besides numerous side effects, orlistat also has many drug-drug interactions. So, if you’re on any medications for heart health, infection, seizure, thyroid disorder, or others, it’s important to consult your health practitioners prior to using orlistat. Also, if you have had kidney stones, gallbladder disease or pancreatitis, it’s important to bring this up as well. 

Lastly, orlistat should be avoided in pregnant or lactating women and in individuals with chronic malabsorption syndrome, cholestasis, or organ transplant.^1-3

The Bottom Line

Orlistat is a weight loss medication indicated for individuals who are overweight with BMI ≥30 kg/m² or a BMI ≥27 kg/m² with other risk factors such as high blood pressure, high cholesterol or type 2 diabetes. While taking 120 mg three times a day with diet modification and physical activity helps to reduce ≥5% weight loss from baseline, it does come with numerous side effects and drug interactions, especially with levothyroxine and multivitamins containing vitamin A, D, E and K.

We hope you took away something valuable from this piece. If you have any questions or concerns regarding this article or others, feel free to reach out to us on Instagram, Facebook, or at ask@orbishealth.ca with your feedback. We’d love to hear from you.

RESOURCES

1. RxTx
2. Lexicomp
3. Truven Health Analytics. DynaMed Plus [Internet]. Ipswich (MA): EBSCO Information Services. 1995 – . Record No. 233579, Orlistat; [updated 2016 Jul 08, cited 2018 Aug 1]; [about 18 screens]. Available from http://www.dynamed.com/login.aspx?direct=true&site=DynaMed&id=233579.
4. DynaMed Plus [Internet]. Ipswich (MA): EBSCO Information Services. 1995 – . Record No. 361156, Weight loss medications for obesity in adults; [updated 2018 Jun 22, cited 2018 Aug 1]; [about 32 screens]. Available from http://www.dynamed.com/login.aspx?direct=true&site=DynaMed&id=361156.