Don’t Miss a Single Update or New Release! Sign up Today

Weight Loss Drugs Contrave, Saxenda, and Xenical Explained

Weight Loss Drugs Contrave, Saxenda, and Xenical Explained
Dr. Constance Odom, MD Picture of Dr. Constance Odom, MD

Medically reviewed by

Written by our editorial team.

Last Edited 5 min read

Weight loss is a common term used to describe the shedding of unwanted fat. It helps us redefine our physical body to suit aesthetic and health ideals. A standard weight loss journey typically includes a controlled diet and exercise, but this combination doesn't always work for everyone. This is where prescription weight loss drugs like Contrave, Saxenda, and Xenical come in. 

These drugs are safe and effective pharmaceutical blends that break through weight loss plateaus without resorting to invasive measures like surgery, which stress the body. They were specifically designed to eliminate stubborn fat while addressing issues that may be fueling weight gain. They are most often used to manage weight-related medical issues and can be used in both long and short treatment plans.

Below we expand more on these products, their abilities, and why they would be an ideal weight loss aid: 


Commonly prescribed to:

  • Patients with a BMI of 28+

  • Patients who have weight-related medical conditions like high blood pressure or cholesterol, type 2 diabetes 

Created by Orexigen Therapeutics, Contrave is an FDA-approved product designed to help adults who have weight-related medical conditions lose weight. It combines the effects of two medications—naltrexone and bupropion which support weight loss in different ways. Naltrexone is an anti-addiction drug used to treat both alcohol and opioid dependency. 

Bupropion, on the other hand, is an anti-depressant used to treat depressive disorders. Although both these products were originally created for other purposes, they produce potent effects that help eliminate fat. The exact details of how Contrave works is unknown however, scientists have found a link between its effects and the brain. According to a study, Contrave affects the hypothalamus and dopamine (hunger and the reward system circuit of the brain) to promote fullness. This reduces food/calorie intake while enhancing energy—accelerated fat burning. 

It also reduces the impulse to eat unhealthy foods (cravings), significantly reducing the negative impact on the present health condition and weight gain. These effects are ideal as evidence shows that weight-related medical conditions typically stop the brain from sending out signals that tell us we are full. Contrave can be used in both short and long-term treatment plans and must be used in conjunction with a controlled diet and moderate exercise routine.


  • Effective at controlling/curbing cravings 

  • Rapid, noticeable results in as little as 4-5 weeks

  • Effectively combines 2 different medications into a single pill for holistic results

  • It can be safely used in long-term treatment plans without enduring any complications or risks 


  • The risk of unusual behavior in the first few weeks of use is possible 

  • High possibility of users experiencing seizures if the proper dosage and usage instructions are not followed 


Commonly prescribed to:

  • Patients with a BMI of more than 27 

  • Patients with weight-related medical problems or obesity with a BMI over 35 

  • Patients with non-diabetic hyperglycemia (high blood sugar) and a high risk of heart problems such as heart attacks and strokes

  • Adolescent children 12-17, with body weight above 132 pounds (60 kg)

Saxenda is an FDA-approved prescription weight loss medicine created by Novo Nordisk. The product aims to reduce the fat ratios in adults and adolescent children with obesity. Unlike other weight loss supplements that come in a tablet form, Saxenda comes in the form of an easy-to-use injectable pen, allowing quicker absorption of the product. 

It uses the active ingredient liraglutide, a compound similar to GLP-1, a hormone that occurs naturally in the body. GLP-1 is typically released from the intestine after a meal to signal feelings of fullness by slowing stomach emptying and reducing appetites. By mimicking these effects, Saxenda successfully helps with weight loss. The product also regulates hormone levels, which fluctuate due to weight-related medical conditions. 

This approach is quite effective and backed by clinical evidence that states liraglutide induces and sustains weight loss in patients with obesity. Its efficacy can be compared to other products.     However, it does provide the benefit of glycemic control (blood sugar control), making it a unique choice. Saxenda must be used in conjunction with a reduced calorie diet and increased physical activity for maximum results to be achieved. On average, users are scheduled to lose approximately at least 5% of their initial body weight after 12 weeks on Saxenda. This amount of weight loss serves as the green light for long-term use. 


  • Saxenda can be taken with or without a meal

  • It can be safely used by adolescents and the elderly 

  • The formulation helps reduce high blood pressure and cholesterol levels

  • Easy-to-use injectable pen that sends medication straight into the bloodstream

  • Weight loss is maintained after discontinuation with little effort and no side effects 

  • It can be beneficial to those with diabetes or at risk of diabetes  as it regulates blood sugar levels

  • Significant body weight reduction can be achieved in short periods if diet and exercise recommendations are adhered to


  • High possibility of experiencing side effects 

  • Only available as an injection which might not suit all users

  • Not approved to treat weight issues caused by type 2 diabetes

  • Not safe to use if patients have a personal/family history of multiple endocrine neoplasia type 2 (MEN2) or medullary thyroid cancer 

  • It may affect how other medications are absorbed into the system because it slows stomach emptying


Commonly prescribed to:

  • Obese patients with a BMI of 30+

  • Overweight patients with a BMI of 27+

  • Patients with other risk factors (high blood pressure, cholesterol, blood lipid profile) who have weight issues

  • Adolescent children 12-17 diagnosed with weight issues

Xenical, also known as Xenical by Roche, is a prescription drug used to tackle weight issues caused by obesity in adults. The FDA-approved drug can safely accelerate weight loss even if other risk factors/ailments, such as high blood pressure, are present. The drug uses a single active ingredient— orlistat to perform its function and has a proven efficacy profile

The capsule form allows the active compound to be absorbed gradually into the bloodstream, lowering the possibility of side effects. Once consumed, the active ingredient in Xenical stops the intestines from absorbing large volumes of fat by blocking the function of lipase, an enzyme that breaks down fat and supports fat storage. By doing this, Xenical helps users eliminate fat cells through excretory processes—bowel emptying.

The product also eliminates the different types of fat found in the liver and abdomen. Evidence shows that liver and abdominal fat fuel the development of serious health issues in obese individuals, making the eradication of these fats extremely beneficial. Pairing the use of this product with a nutritionally balanced/reduced-calorie diet and exercise routine can result in noticeable fat loss in as little as 12-24 weeks. 


  • Approved for use in young (12+) and old patients 

  • Effective at fat blocking and preventing fat storage

  • Available in prescription and over-the-counter (OTC) versions


  • Must be taken with each fat-containing meal

  • A healthy diet and exercise routine are needed for maximum results

Do These Weight Loss Drugs Have Side Effects?

Almost all supplements and treatments come with the possibility of side effects, and prescription weight loss drugs are no exception. Side effects often occur when a new substance is introduced into the body's circulatory system. It typically phases out after a short time and doesn't occur in all users. Below we look at some side effects that may appear while using Contrave, Saxenda, and Xenical:

Name of product

Common side effects


  • Nausea, vomiting, 

  • Constipation, stomach pain

  • Headache, dizziness

  • Strange taste in the mouth or dry mouth


  • Nausea, diarrhea, constipation

  • Vomiting, headache, tiredness

  • Fatigue, dizziness, stomach pain

  • Reaction at the injection site 


  • Oily stool/discharge and excess flatulence 

  • Frequent urge to empty bowels 

  • Inability to control bowel movements or loose stools

Using prescription weight loss treatments according to recommended dosage/usage guides for recommended time frames is the best way to prevent the side effects above from worsening. However, there are some cases where they can be prolonged and grow in intensity due to other underlying causes. In these cases, professional advice/help must be sought out. 

The Bottom Line

Prescription weight loss drugs are definitely a viable option for all those who meet the requirements for use. They have a non-invasive approach and produce potent effects that fuel fat loss in short periods. This makes them a safe, efficient, and effective choice. The options above provide users with permanent results that do not change after use is discontinued considering that diet and exercise initiatives are maintained. It is vital to remember that these products are not magic cures, they are aids that help accelerate weight loss and dislodge stubborn fat, so preservation of a healthy lifestyle is key. Adherence to a low-calorie, low-fat meal plan with a structured exercise regime not only supports successful outcomes but also helps reduce the possibility of adverse effects.  


7 Sources

Nu Image Medical has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your physician about the risks and benefits of any treatment. Nu Image Medical may not offer the medications or services mentioned in this article.