GLP-1 Medicines Explained: What They Are and What to Know
Medicines like semaglutide and tirzepatide are changing how obesity and diabetes are treated. Here is how they work, what trials showed, the side effects, and why they are not a shortcut.
You may have heard names like Ozempic, Wegovy, or Mounjaro in the news. They belong to a family of medicines that copy a natural hormone called GLP-1. They are some of the most talked-about drugs in the world today. This article explains the basics in plain words.
What is GLP-1?
GLP-1 is a hormone your gut releases after you eat. It tells your pancreas to release insulin, slows down how fast your stomach empties, and sends a "full" signal to your brain. GLP-1 medicines copy this effect, but last much longer in the body than the natural hormone.
- Semaglutide (brand names include Ozempic and Wegovy) copies GLP-1.
- Tirzepatide (brand names include Mounjaro and Zepbound) copies GLP-1 and a second gut hormone called GIP.
They were first approved for type 2 diabetes. Some are also approved for weight management in people with obesity, or with overweight and a related health condition.
What trials have shown
In large clinical trials, people taking weekly semaglutide 2.4 mg lost on average about 15 percent of their body weight over around 68 weeks, compared with roughly 2 percent on placebo. In a trial of tirzepatide, the highest dose led to an average weight loss of around 20 percent over about 72 weeks. Both trials combined the medicines with diet and activity advice. Individual results vary a lot.
Common side effects
- Nausea, vomiting, diarrhoea, or constipation, usually worst when starting or raising the dose.
- Reduced appetite, which can mean eating too little protein.
- Less common but serious: gallbladder problems, inflammation of the pancreas, and dehydration leading to kidney problems. Sudden loss of vision in one eye is a rare but urgent reason to get medical help.
- Not recommended during pregnancy.
Who should consider them?
Talk to a doctor first
These are prescription medicines that need a medical check, not something to buy online.
Match them to a health reason
They are meant for people with diabetes or obesity-related health risks, not for small cosmetic weight loss.
Build habits alongside
Eat enough protein, stay active, and strengthen your muscles to protect muscle mass.
Plan for the long term
Ask about how long you will take it, how to stop, and what happens afterwards.
What most people miss
- Fake and unregulated products are a real danger. Counterfeit versions have been sold online. Only use medicine prescribed by a doctor and bought from a licensed pharmacy.
- They are not a replacement for lifestyle. Food quality, sleep, and movement still decide long-term health.
- Research is moving fast. New versions, including tablets and combinations, are being tested, so advice may change.
