Medication Science

How Ozempic Works for Weight Loss: A Deep Dive

Ozempic revolutionized weight loss by mimicking the effects of a hormone called GLP-1, curbing appetite, slowing digestion, and enhancing glucose control, potentially impacting the brain's pleasure centers, thus offering promise beyond diabetes treatment.


  • Friday, April 26, 2024

Given the rapid rise in fame of diabetes-turned-obesity-medications Ozempic, Wegovy and Mounjaro, you may know what they are , but wonder how these medications work. Look no further! We’ve rounded up our experts to explain the mechanisms behind these medications, as well as why they are so revolutionary. If you read our brief overview of the history of weight loss drugs, there may be some overlap. If not, we will explain it all here, both in simple and technical terms.

What is Ozempic?

Ozempic, also known as semaglutide, belongs to a class of medications called GLP-1 receptor agonists. This once-weekly injection works by mimicking the effects of a hormone called glucagon-like peptide-1 (GLP-1), which stimulates insulin production and reduces glucose production by the liver. By increasing insulin secretion and decreasing glucagon secretion, Ozempic helps lower blood sugar levels in individuals with type 2 diabetes.

Approved by the FDA in December 2017, Ozempic was the first semaglutide patent. The FDA approved Ozempic for the treatment of diabetes specifically, but it is often prescribed off-label, or prescribed for something other than diabetes, effectively making it a weight loss medication as well. The version of semaglutide that was approved for weight loss is called Wegovy, which you can read more about here, and the oral version is called Rybelsus, which you can read about here.

The Simple Version: How Does It Work for Weight Loss?

Ozempic's mechanism of action involves increasing feelings of fullness, reducing appetite, slowing down digestion, and improving glucose control, all of which can lead to significant weight loss when combined with a reduced-calorie diet and increased physical activity. By mimicking a hormone that naturally occurs in the gut, which is in turn interpreted by the brain to determine if you are hungry, Ozempic quite simply makes you less hungry.

In other words, Ozempic works by acting on a combination of receptors in the brain and the gut responsible (though not solely) for appetite and cravings, food and otherwise. By acting like the natural hormone GLP-1, Ozempic “tricks” the body into slowing digestion, reducing sugar production in the liver, and feeling full.

Let’s Get Technical: How Does Ozempic Really Work?

  1. GLP-1 Receptor Agonist: Semaglutide is a GLP-1 (glucagon-like peptide-1) receptor agonist. GLP-1 is a hormone produced naturally in the body in response to food intake. It helps regulate blood sugar levels by stimulating insulin release and inhibiting glucagon secretion, which reduces blood sugar levels after meals. GLP-1 also helps to regulate appetite and food intake.
  2. Appetite Regulation: When semaglutide binds to GLP-1 receptors in the brain, it mimics the effects of natural GLP-1. This leads to increased feelings of fullness (satiety) and reduced appetite, which can result in decreased food intake and ultimately weight loss.
  3. Slowing of Gastric Emptying: Semaglutide also slows down the rate at which the stomach empties food into the small intestine. This can help to prolong feelings of fullness after meals and reduce the urge to eat again soon after eating, contributing to overall calorie reduction and weight loss.
  4. Improvement in Glucose Control: In addition to promoting weight loss, semaglutide can also improve glucose control in people with type 2 diabetes. By enhancing insulin secretion and reducing glucagon levels, it helps to lower blood sugar levels, which may also contribute to weight loss and metabolic improvements.

Doesn’t seem very complicated? Just wait, it gets better. The Atlantic published an article in March arguing scientists were wrong about Ozempic the whole time — that the weight loss benefits of Ozempic are more likely due to effects in the brain than the gut. While it is already well documented that Ozempic curbs food cravings, there have been a number of studies in rats that have shown beneficial effects for other cravings as well, such as addictions and dependencies. Could Ozempic be more than a diabetes and weight loss medication?

In monkeys and rodents, virtually all of the GLP-1s have some effect on the pleasure system of the brain, affecting nearly every substance abuse disorder, including alcohol, cocaine, amphetamines and opioids. They differ, however, on what substances are affected as well as how long the treatments remain effective. Some GLP-1s only have acute effects, while others appear to have long-term effects. There is more research needed, but there some experts think that part of Ozempic’s effectiveness in reducing hunger are due to effects on the reward and pleasure center of the brain typically activated by food — the very idea posited by the Atlantic article linked above.

Why is Ozempic Revolutionary?

Compared to traditional weight loss options, like phentermine and miracle pills, Ozempic is both safer and more effective. For nearly 80 years, the best available weight loss medications averaged reductions below 10% of body weight. Double digit reductions in body weight were virtually unheard of, and medication recalls like that of fen-phen, a combination of fenfluramine and phentermine, were commonplace. With the development of GLP-1 medications like Ozempic and Mounjaro, side effects are typically digestive in nature. While individuals seeking weight loss used to bear the risk of cardiac damage, like with fen-phen, now they risk more mild side effects like constipation and nausea. Note: by no means are we saying Ozempic is without serious **side effects, but it is inarguable that their safety profile is better. New emerging research offers hope of even greater things for Ozempic, with potential to treat even psychological conditions.

Final Notes

The rise of medications like Ozempic, Wegovy, and Mounjaro represents a significant breakthrough in the treatment of obesity, offering both safety and efficacy compared to traditional weight loss options. By mimicking the effects of natural hormones and influencing appetite regulation, digestion, and glucose control, these medications provide a comprehensive approach to weight management. Moreover, emerging research suggests potential benefits beyond weight loss, including effects on the brain's pleasure centers and the treatment of psychological conditions. With their improved safety profiles and promising therapeutic potential, these medications herald a new era in obesity treatment, offering hope to millions seeking effective and sustainable solutions for weight management.

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