GLP-1 medications are a class of drugs that mimic a hormone your gut naturally produces after eating, and they’ve become some of the most prescribed medications in the United States. If you’ve heard of Ozempic, Wegovy, or Mounjaro, you’ve heard of GLP-1s. This guide covers what GLP-1 means, how the medications work, what they’re approved […]
By Astra Editorial Team
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GLP-1 medications are a class of drugs that mimic a hormone your gut naturally produces after eating, and they’ve become some of the most prescribed medications in the United States. If you’ve heard of Ozempic, Wegovy, or Mounjaro, you’ve heard of GLP-1s.
This guide covers what GLP-1 means, how the medications work, what they’re approved to treat, how effective the clinical evidence shows them to be, and what you should understand about side effects and who shouldn’t take them.
Quick answer: GLP-1 stands for glucagon-like peptide-1, a hormone your body produces naturally in the lining of your small intestine.
Whenever you eat, your gut sends out a chemical message that helps you handle the meal. It tells your body to deal with the sugar coming in, slows everything down so you don’t get a rush, and lets your brain know you’re full. The net effect is that blood sugar stays more stable after meals and you feel satisfied sooner.
The problem is that natural GLP-1 breaks down in the body within minutes, which is simply too fast to have a sustained therapeutic effect. GLP-1 receptor agonist medications solve this by mimicking the hormone’s structure while being engineered to last much longer: hours to days depending on the specific drug.
In clinical terminology, you’ll see these drugs called GLP-1 receptor agonists, GLP-1 RAs, incretin mimetics, or GLP-1 analogs. They all refer to the same class.
A 5-minute health profile at Astra gets reviewed by a licensed clinician who tells you whether you qualify, what dose fits, and what your options look like.
Start your health profile →Quick answer: GLP-1 medications are a long-lasting copy of a signal your body already sends every time you eat. Normally, that signal lasts only a few minutes; the medication keeps it switched on for days, which is why it does far more than diet or willpower can on their own.
GLP-1 medications are basically that same message, rebuilt to last. Instead of switching off almost right away, it stays on for days. Here’s what that steady signal does:
Scientists are still working out the finer details. A 2026 study published in Nature Metabolism found that the hunger-lowering effect runs through one specific chemical switch in a small part of the brain, which may help explain why these medications work better for some people than for others.
Tirzepatide (Mounjaro, Zepbound) is technically a dual agonist: it activates both the GLP-1 receptor and a second receptor called GIP (glucose-dependent insulinotropic polypeptide). GIP is another gut hormone involved in insulin secretion and fat metabolism.
By targeting both receptors, tirzepatide produces larger effects on weight and blood sugar than GLP-1 alone, which is reflected in its clinical results. You’ll often see tirzepatide grouped under “GLP-1 medications,” even though it’s more precisely a GLP-1/GIP co-agonist.
Quick answer: GLP-1 medications are FDA-approved for three primary uses: type 2 diabetes management, chronic weight management in people with obesity or overweight, and cardiovascular risk reduction.
GLP-1 medications were originally developed as diabetes drugs. They lower A1C effectively and, unlike insulin and some other diabetes medications, do not cause weight gain. Several formulations, including semaglutide as Ozempic and Rybelsus, dulaglutide as Trulicity, and tirzepatide as Mounjaro, carry FDA approval specifically for type 2 diabetes management.
Higher-dose formulations of GLP-1s are approved for weight management in adults with a BMI of 30 or higher, or a BMI of 27 or higher with at least one weight-related condition such as high blood pressure, type 2 diabetes, or high cholesterol.
In December 2025, the World Health Organization issued its first global guideline on GLP-1 therapies for obesity, recognizing the scale of the condition and the strength of evidence supporting these medications as a treatment component alongside lifestyle changes.
Wegovy (semaglutide 2.4 mg) received FDA approval in 2024 to reduce the risk of serious cardiovascular events in adults with established cardiovascular disease who also have obesity or overweight.
This approval followed the SELECT trial, a large randomized controlled trial of over 17,000 people that found semaglutide reduced the combined risk of cardiovascular death, nonfatal heart attack, or nonfatal stroke by 20% compared to placebo, over approximately 40 months of follow-up.
Research published in 2025 summarized GLP-1 medications’ effects beyond diabetes and weight loss, including improved outcomes in people with fatty liver disease, obstructive sleep apnea, chronic kidney disease, and inflammatory arthritis. Some of these benefits appear at least partly independent of how much weight is lost.
These indications are active areas of clinical investigation, and some are beginning to move toward regulatory approval.
Astra makes GLP-1 access straightforward: complete a health profile, a licensed clinician at Wasef Health, PC reviews your case, and if you’re a fit, your medication ships to you. Brand-name or compounded, depending on what suits you best.
Start your health profile →As of 2026, the most widely used GLP-1 and GLP-1/GIP medications in the US include the following:
| Brand Name | Generic Name | Form | FDA-Approved Use |
|---|---|---|---|
| Ozempic | Semaglutide | Injectable, once weekly | Type 2 diabetes |
| Wegovy | Semaglutide | Injectable, once weekly (higher dose) | Weight management; cardiovascular risk reduction |
| Rybelsus | Semaglutide | Oral tablet, daily | Type 2 diabetes |
| Mounjaro | Tirzepatide | Injectable, once weekly | Type 2 diabetes |
| Zepbound | Tirzepatide | Injectable, once weekly | Weight management |
| Victoza | Liraglutide | Injectable, daily | Type 2 diabetes |
| Saxenda | Liraglutide | Injectable, daily | Weight management |
| Trulicity | Dulaglutide | Injectable, once weekly | Type 2 diabetes (also has CV benefit evidence in diabetic patients) |
| Foundayo | Orforglipron | Oral tablet, daily | Weight management |
Orforglipron (Foundayo) is the first oral GLP-1 receptor agonist approved for weight management, following FDA approval in April 2026. This is a good option for people who prefer to avoid injections entirely; most other weight-management GLP-1s are weekly injections.
Compounded semaglutide and tirzepatide. Compounded GLP-1s (pharmacy-prepared formulations of the same active ingredients) have been widely available during periods of shortage of brand-name products.
According to a recent survey of 5,000 adults conducted by Gallup: “About four in 10 compounded or custom-mixed users (39%) report that they are ‘extremely effective,’ compared with 32% of brand-name users.”
Compounded GLP-1s are not FDA-approved, meaning the specific compounded formulation has not gone through FDA’s review process, though the active ingredients themselves are. They’re typically available at significantly lower cost than brand-name versions. If you’re considering this route, confirm current availability with a licensed prescriber or telehealth provider.
Astra offers both, so you don’t have to figure it out alone. A licensed clinician reviews your health profile, insurance situation, and goals, and recommends the option that actually fits your case.
Start your health profile →Quick answer: The clinical evidence for GLP-1 medications in weight loss is the strongest seen for any class of obesity drugs to date.
In the STEP 1 trial, adults with obesity who took semaglutide 2.4 mg lost an average of approximately 15% of their body weight over 68 weeks, compared to around 2.4% with placebo. In real-world settings, average weight loss tends to run a few percentage points lower than trial results, which is more due to the controlled conditions and close monitoring typical of clinical studies.
Tirzepatide has shown even larger effects. In head-to-head comparison in the SURMOUNT-5 trial, which directly compared tirzepatide and semaglutide, participants taking tirzepatide lost an average of 20.2% of their body weight at 72 weeks, compared to 13.7% for semaglutide. Tirzepatide’s higher number reflects its dual GIP/GLP-1 mechanism.
| Medication | Trial | Duration | Average weight loss | Comparator |
|---|---|---|---|---|
| Semaglutide 2.4 mg | STEP 1 | 68 weeks | ~15% | 2.4% (placebo) |
| Semaglutide 1.7-2.4 mg | SURMOUNT-5 | 72 weeks | 13.7% | — (head-to-head) |
| Tirzepatide 10-15 mg | SURMOUNT-5 | 72 weeks | 20.2% | — (head-to-head) |
Weight loss requires continued treatment. This is one of the most common questions people have, and the honest answer is that the weight tends to come back. In the STEP 1 trial extension, participants who stopped semaglutide regained about two-thirds of the weight they had lost within a year.
GLP-1s are not designed for short-term intervention. They’re chronic medications for a chronic condition. So while keeping weight off after stopping is possible, it takes the same lifestyle habits (protein, fiber, strength training, activity) that support the medication in the first place.
Quick answer: Yes. Some of the weight you lose on a GLP-1 is muscle, not just fat. But it’s largely preventable, and it’s not unique to these drugs.
Body composition data from the major trials shows that roughly 25-40% of total weight lost on GLP-1 medications comes from lean mass, which includes muscle. In the STEP 1 body composition substudy, close to 40% of the weight lost on semaglutide was lean tissue. Tirzepatide substudies have shown a somewhat lower proportion, closer to 25%.
That ratio is normal for any rapid weight loss, whether from diet, surgery, or medication. When you lose a lot of weight quickly, some of it comes from muscle unless you actively work to protect it. The absolute numbers look large because the total weight loss is large.
The concern is more pronounced in older adults and in women, both of whom tend to lose a higher share of muscle. And losing too much muscle isn’t just a cosmetic or strength issue. Research suggests it can blunt some of the metabolic benefits of the medication, including blood sugar control.
The good news is that muscle loss responds well to two things:
Quick answer: The most common side effects of GLP-1 medications are gastrointestinal, and most occur during dose escalation.
Nausea, vomiting, diarrhea, constipation, and stomach discomfort are the side effects reported most frequently. In the STEP and SURMOUNT trials, somewhere between 80% and 90% of participants experienced at least one side effect. The majority were mild to moderate, and rates of stopping treatment due to side effects were considerably lower than the headline adverse event numbers suggest.
Nausea tends to be most pronounced in the first few weeks after starting or increasing a dose, then diminishes as the body adjusts. Most prescribers use a gradual dose escalation schedule specifically to minimize this.
| Side effect | Frequency | Notes |
|---|---|---|
| Nausea | Common | Most pronounced during dose escalation; usually eases with time |
| Vomiting, diarrhea, constipation | Common | Gastrointestinal effects are the most frequently reported |
| Stomach discomfort | Common | Often manageable with slower dose escalation |
| Gallbladder issues / gallstones | Less common | Linked to rapid weight loss generally |
| Increased resting heart rate | Less common | Usually a few beats per minute; discuss if you have arrhythmia history |
| Pancreatitis | Rare | Seek care for severe, persistent abdominal pain |
| Thyroid C-cell tumors | Rare (black box warning) | Seen in rodent studies; not confirmed in humans |
More serious but less common risks include:
The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) and other regulators are actively monitoring GLP-1 medications for additional signals, including potential links to depression and suicidal ideation, though current evidence does not establish a clear causal relationship.
Quick answer: You should not take semaglutide or tirzepatide if you have a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia type 2 (MEN2).
Other situations that typically warrant caution or rule out GLP-1 medications include:
GLP-1 medications are also intended for people who are overweight or have obesity for medical reasons, not cosmetic weight loss. Regulatory guidance from both the FDA and international health authorities is consistent on this point.
Astra’s health profile takes about 5 minutes. A licensed clinician reviews it, and if compounded or brand-name GLP-1 fits your case, you’re on your way.
Start your health profile →Quick answer: Most GLP-1 medications are weekly subcutaneous injections, meaning you inject a small amount of medication just under the skin, typically in the abdomen, outer thigh, or back of the upper arm.
The injections use a pre-filled pen device and a very small needle. Most people find them manageable with minimal discomfort after the first few uses.
Treatment begins at a low dose and escalates gradually over several months to the target maintenance dose. This ramp-up process is designed to let your body adjust and minimize side effects. For semaglutide (Wegovy), the escalation schedule typically spans about 16 weeks before reaching the full 2.4 mg maintenance dose.
Oral options now exist in several forms: Rybelsus (semaglutide) is a daily tablet approved for type 2 diabetes, and orforglipron (Foundayo) is the first once-daily oral GLP-1 approved for weight management. Oral GLP-1 options may suit people who strongly prefer not to inject.
Compounded semaglutide and compounded tirzepatide may also be available from licensed telehealth providers and compounding pharmacies, typically at lower cost than brand-name options. The administration is the same (weekly subcutaneous injection) but the formulation comes from a compounding pharmacy rather than the original manufacturer.
Quick answer: Yes, your body releases GLP-1 every time you eat, and certain foods stimulate more of it. But no food comes close to the effect of the medications.
GLP-1 is a hormone you produce naturally, and what you eat influences how much of it your gut releases after a meal. Three categories of food are the strongest triggers:
You’ll also see a lot of buzz online about specific tricks. Apple cider vinegar, for instance, is often claimed to “act like a GLP-1.” Some small studies suggest vinegar can slightly slow gastric emptying and blunt post-meal blood sugar spikes, but this is a minor effect and not comparable to what the medications do.
The so-called “lazy GLP diet” and similar trends are essentially repackaged versions of the same advice: eat protein and fiber first, don’t rush your meals. It’s useful advice for appetite and blood sugar, just not a substitute for medication if you have obesity or diabetes.
Eating to support your natural GLP-1 is good for almost everyone. It improves satiety, steadies blood sugar, and comes with cardiovascular and other benefits that the food itself provides. But natural GLP-1 release is measured in small, short-lived amounts.
GLP-1 medications produce a sustained effect many times stronger, which is why they work for conditions that diet alone often cannot resolve. Think of the food approach as something that helps whether or not you’re on a medication, and not as a replacement for one.
If you’re considering a GLP-1 medication, these are the questions worth covering with your prescriber.
If you want to understand your options in more depth, a good next step is learning about how GLP-1 costs and coverage work, or comparing the specific medications to understand which might be a better fit for your situation.
Astra pairs licensed clinicians at Wasef Health, PC with a US-licensed 503A pharmacy so getting started is straightforward and supported end-to-end.
Start your health profile Takes about 5 minutes.Not exactly. Ozempic is one specific GLP-1 medication. It’s the brand name for semaglutide approved to treat type 2 diabetes. “GLP-1” refers to the entire class of medications, which includes semaglutide (Ozempic, Wegovy, Rybelsus), tirzepatide (Mounjaro, Zepbound), liraglutide, dulaglutide, and others. So every Ozempic is a GLP-1, but not every GLP-1 is Ozempic.
Nausea is by far the most common. It tends to be worse in the first few weeks and after each dose increases, then it eases as your body adjusts. Other frequent gastrointestinal effects include vomiting, diarrhea, and constipation. Most side effects are mild to moderate, but rarer serious risks (pancreatitis, gallbladder problems, and a boxed warning about thyroid tumors) are why these are prescription-only medications.
The organs most relevant to GLP-1 side effects are the pancreas and gallbladder. There’s a warning about pancreatitis (pancreas inflammation), and rapid weight loss of any kind raises the risk of gallstones. The medications carry a boxed warning about thyroid C-cell tumors based on rodent studies, though this hasn’t been confirmed in humans.
For most people, GLP-1s are actually protective of the heart and kidneys. The SELECT trial found semaglutide reduced both cardiovascular events and kidney-related outcomes.
In the only head-to-head trial to date (SURMOUNT-5), tirzepatide produced greater weight loss than semaglutide: about 20% versus 14% of body weight.
Usually, yes. Because GLP-1 medications treat a chronic condition rather than cure it, stopping typically leads to appetite returning and weight coming back. In the STEP 1 trial extension, people who stopped semaglutide regained about two-thirds of their lost weight within a year. Maintaining weight after stopping is possible but requires sustained lifestyle habits, and some people stay on a lower maintenance dose long-term.
It’s harder but possible. The appetite suppression makes it difficult to eat enough protein, and the calorie deficit that drives weight loss also works against muscle building. That said, people who prioritize protein (around 1.2–1.6 g/kg/day) and do regular resistance training can preserve lean mass while losing fat on a GLP-1. Without that effort, expect to lose some muscle along with the fat.
This article is for educational purposes only and does not constitute medical advice. Consult a licensed physician regarding any medical condition or treatment.