How do weight loss drugs work? There are different kinds of weight loss drugs, but the most common ones work by suppressing appetite and slowing down how fast the stomach is emptied.
A large percentage of people in developed countries are becoming seriously obese. There are many reasons for this. The prevalence of ultra-processed food and the fact that it is far cheaper than real food is often cited as a reason, although there are many reasons and they differ from person to person and country to country. According to worldobesity.org, all of the top ten most obese countries are located among the Polynesian islands. Nauru is top with 94.5% of the population being classified as obese. Diabetes and heart disease are very common. The main cause of this is a change in diet from the traditional Pacific Island diet to a western diet high in salt and fat, primarily ultra-processed. Unfortunately, these new wonder weight loss drugs are very expensive and will probably not be making an appearance in the Pacific Islands for many years to come.
So, what are the weight loss drugs and how do they work? There are two drugs currently being marketed. They are semaglutide and tirzepatide. They are sold under the brand names Wegovy and Mounjaro. Semaglutide first came to the market under the brand name Ozempic, which is when weight loss drugs first became popular and famous. Ozempic is a diabetes drug and not a weight loss drug. Both semaglutide and tirzepatide can cause weight loss, but they do it in a different way.
Semaglutide is a GLP-1 receptor agonist. GLP-1 stands for glucagon-like peptide-1. GLP-1 is a hormone that is released after eating in the intestines. GLP-1 is produced and land on GLP-1 receptors, which send signals to decrease blood sugar levels by making the body produce more insulin and to the brain to say that the intestines are full. It suppresses appetite. When you take semaglutide, it mimics the GLP-1 that your body produces and tricks it into thinking that you are full. You produce more insulin, bringing your blood sugar levels down, and you feel full, even if you are not. Because you feel full, you eat less and because your blood sugar is controlled you have fewer cravings.
Tirzepatide also mimics GLP-1 and has the same effects as semaglutide, but it works in another way as well. Tirzepatide acts on gastric inhibitory polypeptide (GIP) receptors as well. GIP is produced in the small intestine and stimulates insulin release. It also affects the body’s metabolism, reduces the appetite, and slows down the speed that the stomach empties. Tirzepatide works in more ways that semaglutide and is therefore a more effective drug.
These drugs were basically discovered by accident. People have been trying to come up with a weight loss drug for decades and it is often seen as the holy grail of medicine. A Danish drug company called Novo Nordisk was trying to come up with a drug that could help diabetes patients. Scientists came up with a drug that could mimic the GLP-1 hormone and attach to the receptors. This controlled the body’s insulin level and kept blood sugar levels under control. The drug was semaglutide. It appeared to be a very promising diabetes drugs and research continued. During their human testing phase, they noticed that people who took the drug became so full that they were often unable to finish their meals. When the drug was released onto the market as Ozempic, it was a diabetes drug, but word of its weight loss effects started to spread and became very popular. There were rumors that a lot of celebrities in Hollywood were using the drug to lose weight. Because of this publicity, and even though it was a diabetes drug, Ozempic brought in billions of dollars for Novo Nordisk. Soon after, Novo Nordisk released a drug that was just for weight loss and a company called Eli Lilly released the first trizepatide weight loss drug called Maunjaro. That has brought them billions as well.
People who take these drugs can lose a lot of their weight. Some people have lost 15 to 20% of their body mass. However, there are a fair few side effects. Nausea and vomiting appear to be the most common and people who are on the drugs have to be careful about what they eat. The drugs are also very expensive. They are not covered by insurance in most countries, unless you have serious medical issues, which means people need to buy them and they are very expensive. Mountjaro is about $1,000 a dose and you need a dose a week. People start to pay and lose weight, but if you stop taking the drugs, the weight comes back, so people have to keep paying. That is not always an option. The companies say that the price has to be high to pay for all the money they pumped into research. The patents will run out in about 2026, so cheaper generic versions will start to appear. I guess the companies need to make as much money as they can before then. And this is what I learned today.
Photo by Pixabay: https://www.pexels.com/photo/close-up-photo-of-medicinal-drugs-159211/
Sources
https://www.mayoclinic.org/healthy-lifestyle/weight-loss/in-depth/weight-loss-drugs/art-20044832
https://www.health.harvard.edu/staying-healthy/understanding-new-weight-loss-drugs
https://www.bbc.com/news/articles/c981044pgvyo
https://en.wikipedia.org/wiki/Semaglutide
https://en.wikipedia.org/wiki/Tirzepatide
https://en.wikipedia.org/wiki/Gastric_inhibitory_polypeptide_receptor
https://en.wikipedia.org/wiki/Glucagon-like_peptide-1
https://data.worldobesity.org/rankings/?age=a&sex=t
https://en.wikipedia.org/wiki/Obesity_in_the_Pacific
https://www.wired.com/story/obesity-drugs-researcher-interview-ozempic-wegovy