The World of Weight Loss Medications


The quest for effective weight loss solutions is an ongoing journey for millions of people worldwide. As obesity rates continue to rise, there is a growing demand for safe and effective weight loss medications. While a balanced diet and regular exercise are the cornerstones of any weight loss journey, some people may require additional support to achieve their goals. This article will delve into the world of weight loss medications, providing an overview of their effectiveness, safety, and types available on the market.

Obesity is a complex, multifactorial condition that can significantly impact an individual’s quality of life and increase the risk of various health complications, including type 2 diabetes, cardiovascular diseases, and certain types of cancer, like colon cancer.  For some individuals, lifestyle modifications alone may not be enough to achieve significant weight loss. In such cases, weight loss medications may be needed as a supplementary tool to assist in achieving and maintaining a healthy weight.

Weight loss medications work through various mechanisms, targeting different aspects of the weight regulation process. The most common types of weight loss medications include GLP-1 (glucagon like peptide 1) agonists, appetite suppressants, and fat absorption inhibitors.

We will start with a discussion of GLP-1 inhibitors as these medications have garnered a lot of media attention recently (i.e. Ozempic, Saxenda, Wegovy).  These medications are related to a class of hormones called incretins.  Incretins are released from the gastrointestinal tract after a meal and, among other things, cause a sense of satiety (fullness), making individuals who take them feel less hungry.  A similar medication, Mounjaro, is undergoing FDA approval for use in weight loss.  They are administered as weekly or daily injections.  Generally, people taking these medications can expect a 5-15% weight loss.  They can cause gastrointestinal side effects like nausea, vomiting, and diarrhea.  The medication is started at a low dose and gradually increased while monitoring for side effects.  In rare cases the medications can cause serious side effects like pancreatitis, which is inflammation of the pancreas.  Cancers have developed in some animal studies, though the significance of this for humans is unknown.  Cost can be a factor with these medications.

Appetite suppressants help to reduce hunger and promote satiety by acting on neurotransmitters in the brain.  Some medications in this class are sympathomimetic drugs that activate the “fight or flight” nervous system response and suppress appetite in this manner.  Examples include phentermine (Adipex-P) and diethylpropion (Tenuate).  These are controlled substances, as they can cause dependence in some people.  They are administered as oral pills usually taken once a day.  There is a combination pill (Qysmia) that adds topiramate (an antiseizure medication) to phentermine and can achieve an 8-10% weight loss.  Another medication in this category is Contrave, which is not a controlled substance.  Contrave combines bupropion (a dopamine reuptake inhibitor) and naltrexone (an opioid receptor antagonist).  This medication is thought to control cravings by acting on the dopamine areas in the midbrain.  It has been shown to produce around a 5% weight loss.  Generally, this class of medication can cause high blood pressure, constipation, and nervousness.  They are not ideal for people with cardiovascular disease or anxiety.

Fat absorption inhibitors block the absorption of fat in the digestive tract.  Orlistat (Xenical, Alli) is the most well-known example of this type of medication.  It works by inhibiting the enzymes that breakdown fat in the digestive track.  Fat that is not broken down cannot be digested and is excreted in stool.  This leads to lower amounts of fat and hence calories entering the body.  The medication is an oral pill and people taking it have lost about 8% of baseline weight.  Side effects of the medication include diarrhea, abdominal cramping, gas, and incontinence of stool.  More serious reported side effects including liver injury and kidney stones.

Weight loss medications are not a “magic pill” or a one-size-fits-all solution. They should be used as part of a comprehensive weight management plan that includes a balanced diet, regular physical activity, and behavior modification. These medications can provide additional support for individuals struggling to lose weight through lifestyle changes alone, but they are not a substitute for a healthy lifestyle.  As always, it is important to consult with a trusted clinician before undertaking treatment with any of these medications.