Here at WeightSimple.com, we combine the latest scientific data in conjunction with our specialised expertise to help our patients lose weight in an effective, sustained and safe manner. GLP-1 agonists such as Wegovy, Rybelsus and Ozempic remain the most common medications prescribed for weight loss. For more information on how they work, please see here.

How effective will weight management medications be for me?

Every patient has a unique body anatomy, metabolism and response to medications. However, there have been many large, well conducted scientific studies which have demonstrated safety and effectiveness of these medications.

This Belgian semaglutide study is a great example:

• In 2021, a large trial comprised of clinicians from England, Belgium, United States, Canada and Japan examined the effectiveness of semaglutide (active ingredient in Wegovy, Rybelsus and Ozempic) for weight loss in people without diabetes. This trial is commonly referred to as the STEP-1 Study1.
• A total of 1,961 adult patients were enrolled in this study across 129 separate centres in Asia, Europe, North America, and South America. These patients all had a BMI of over 30, or at least 27 with one or more weight-related complications such as blood pressure, high cholesterol or sleep apnea. Most importantly, every single one of these patients have previously unsuccessfully tried to lose weight, through either diet, lifestyle, or exercise.
• These patients were randomly assigned to either receive semaglutide through a once weekly injection, or placebo. Neither the patient nor the trial coordinators knew what the patients were receiving, as the placebo group received an identical subcutaneous injection without a medically active ingredient. These patients were followed for a total of 68 weeks. In addition to receiving medication (real or placebo), all of the patients also received lifestyle intervention such as dietary counselling and exercise.

At the end of 68 weeks, patients receiving semaglutide had an average weight loss of 14.9%. In the patients receiving placebo (no active medication at all), they had an average weight loss of 2.4%. Patients receiving semaglutide also had a decrease in average waist circumference of 13.5 cm and an average reduction in blood pressure of 6.2 mmHg.

Similar studies exist

Since 2021, there have been many additional studies which have revealed very similar results. The SELECT2 trial was published in 2023. This study included 17,604 patients and took place in 800 different sites across 41 different countries over two years. This study found an average weight loss of 9.3% for patients receiving the active medication, reduction in waist circumference of 7.5 cm and reduction in blood pressure of 3.7 mmHg.

These studies, in conjunction with many other similar trials have shown that with the appropriate medication, expertise in titration and lifestyle changes, patients can expect to lose between 10 to 15% of their baseline weight.

What side effects can I expect from medications like Ozempic® and Contrave?

Common G.I. side effects, such as nausea, vomiting, indigestion or constipation occurred in 74% of patients receiving semaglutide treatment. While this number appears high at first; in patients receiving placebo (no active medical ingredient) nearly 50% also experienced similar side-effects. Therefore, we can infer that a large portion of these side effects come from losing weight in general, rather than directly from medications.

Other more serious side effects such as acute pancreatitis or development of certain types of cancers, occurred exceedingly rare in both groups. 0.2% of patients receiving semaglutide developed pancreatitis, and a similar number of patients in both groups (1%), developed a new cancer. Given such a small percentage of patients were affected, it is difficult to conclude if these are a result of the medication or simply by chance. Ultimately what we can conclude is these medications are very safe, with common but simple side effects, which can be easily managed with the expertise of our clinical team.

What about Contrave®? Is it just as effective for weight loss?

Contrave is another new weight loss medication, in a different class compared to Ozempic, Wegovy or Rybelsus. Contrave has two active medical ingredients: Wellbutrin, a commonly prescribed antidepressant; and Naltrexone, an opioid receptor antagonist.

A number of clinical trials have been conducted using Contrave (COR-I3, COR-II4 and COR-BMOD5). Results of these trials found that patients taking Contrave experienced between 8.1% to 11.5% reduction in body weight. Common side effects such as nausea, constipation and vomiting were reported in 10 to 30% of the patients taking the medication, compared to between 3 to 10% of patients taking the placebo. Again, the side effects are minor and can be easily managed by our clinical team.

Okay, so it looks like these weight loss medications can be effective. Can’t I just get a prescription for weight loss medication from my GP like any other medication?

Yes, many more family doctors are starting to prescribe weight loss medications. However, these medications are very novel and the experience in a primary care setting is still limited. We see many patients who are prescribed these medications unable to continue treatment due to side effects, or never even reaching target dose due to difficulties in titration. Ultimately these attempts result in no sustained weight loss, and inadequate management of common side effects make many patients highly frustrated. Additionally, in order to achieve sustained, long lasting weight loss; a multifaceted approach is essential. At Weightsimple, not only do we have the medical expertise in the use of these medications, we have a full complement of allied health professionals, such as dietitians, behaviourists, psychiatrists and pharmacists, who all bring their own expertise in your weight loss journey.

Click here to speak to one of our clinicians and take the first step of your final weight loss journey.

References:

1. Wilding JPH, Batterham RL, Calanna S, Davies M, Van Gaal LF, Lingvay I, McGowan BM, Rosenstock J, Tran MTD, Wadden TA, Wharton S, Yokote K, Zeuthen N, Kushner RF; STEP 1 Study Group. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021 Mar 18;384(11):989-1002. doi: 10.1056/NEJMoa2032183. Epub 2021 Feb 10. PMID: 33567185.

2. Lincoff AM, Brown-Frandsen K, Colhoun HM, Deanfield J, Emerson SS, Esbjerg S, Hardt-Lindberg S, Hovingh GK, Kahn SE, Kushner RF, Lingvay I, Oral TK, Michelsen MM, Plutzky J, Tornøe CW, Ryan DH; SELECT Trial Investigators. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes. N Engl J Med. 2023 Dec 14;389(24):2221-2232. doi: 10.1056/NEJMoa2307563. Epub 2023 Nov 11. PMID: 37952131.

3. Greenway FL, Fujioka K, Plodkowski RA, Mudaliar S, Guttadauria M, Erickson J, Kim DD, Dunayevich E; COR-I Study Group. Effect of naltrexone plus bupropion on weight loss in overweight and obese adults (COR-I): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial. Lancet. 2010 Aug 21;376(9741):595-605. doi: 10.1016/S0140-6736(10)60888-4. Epub 2010 Jul 29. Erratum in: Lancet. 2010 Aug 21;376(9741):594. Erratum in: Lancet. 2010 Oct 23;376(9750):1392. PMID: 20673995.

4. Apovian CM, Aronne L, Rubino D, Still C, Wyatt H, Burns C, Kim D, Dunayevich E; COR-II Study Group. A randomized, phase 3 trial of naltrexone SR/bupropion SR on weight and obesity-related risk factors (COR-II). Obesity (Silver Spring). 2013 May;21(5):935-43. doi: 10.1002/oby.20309. PMID: 23408728; PMCID: PMC3739931.

5. Wadden TA, Foreyt JP, Foster GD, Hill JO, Klein S, O'Neil PM, Perri MG, Pi-Sunyer FX, Rock CL, Erickson JS, Maier HN, Kim DD, Dunayevich E. Weight loss with naltrexone SR/bupropion SR combination therapy as an adjunct to behavior modification: the COR-BMOD trial. Obesity (Silver Spring). 2011 Jan;19(1):110-20. doi: 10.1038/oby.2010.147. Epub 2010 Jun 17. PMID: 20559296; PMCID: PMC4459776.