What Is Semaglutide Used For? A Science-Backed Guide to Its Real Benefits and Risks

When a drug generates this much cultural noise, it helps to cut through the hype and look at what the science actually says. Semaglutide — sold under brand names Ozempic and Wegovy — has become one of the most discussed medications of the decade. And for good reason. A 2022 systematic review and meta-analysis found that subcutaneous semaglutide produced an average 11.85% reduction in body weight compared to placebo in people with obesity who didn’t have diabetes. That’s not a rounding error. That’s a clinically meaningful shift in body composition — the kind that moves the needle on blood pressure, metabolic markers, and cardiovascular risk.

But understanding what semaglutide is actually used for — beyond the headlines — requires looking at the mechanism, the approved indications, the clinical trial data, and the real-world tradeoffs. Whether you’re considering it, currently using it, or simply trying to understand what all the noise is about, here’s what the evidence shows.

What Semaglutide Is and How It Works

Semaglutide is a glucagon-like peptide-1 receptor agonist, or GLP-1 RA. GLP-1 is a hormone your gut naturally releases after eating. It stimulates insulin secretion, suppresses glucagon, slows gastric emptying, and — critically — acts on appetite-regulating centers in the brain to reduce hunger and caloric intake. Semaglutide is a synthetic analog of that hormone, engineered to have a much longer half-life than the natural version, which is why it can be dosed once weekly by injection or daily in oral form.

As Smits and Van Raalte noted in their 2021 safety review, semaglutide is unique among GLP-1 receptor agonists in that it’s the only agent in the class available in both subcutaneous and oral formulations — a significant development for patient accessibility and adherence. The drug was originally developed and FDA-approved for type 2 diabetes management, where its ability to improve glycemic control while also producing meaningful weight loss set it apart from other antidiabetic agents.

The weight loss effect isn’t just a side benefit — it became the entire second act of the drug’s story. As Singh, Krauthamer, and Bjalme-Evans outlined in their 2022 review, data from the SUSTAIN, PIONEER, and STEP clinical trial programs collectively demonstrated that semaglutide — whether injected or oral — outperformed placebo and other antidiabetic medications in weight reduction across a range of patient populations. This evidence base is what ultimately led to FDA approval of Wegovy (semaglutide 2.4 mg) specifically for chronic weight management.

The Two Primary FDA-Approved Uses

Semaglutide currently has two distinct FDA-approved indications, and understanding the difference matters. As Ozempic (1.0 mg, once weekly subcutaneous injection), it’s approved for glycemic control in adults with type 2 diabetes and to reduce cardiovascular risk in those with established cardiovascular disease. As Wegovy (2.4 mg, once weekly), it’s approved for chronic weight management in adults with a BMI of 30 or above, or 27 and above with at least one weight-related comorbidity.

The STEP 2 trial, published in The Lancet in 2021, demonstrated what the higher dose can do even in people who already have type 2 diabetes. Participants on semaglutide 2.4 mg lost an estimated 9.6% of body weight by week 68, compared to just 3.4% in the placebo group. Nearly 69% of participants on the higher dose achieved at least 5% body weight reduction — a threshold associated with meaningful improvements in metabolic health markers. That’s a compelling signal, especially in a population where weight loss is notoriously difficult to sustain.

It’s also worth noting what semaglutide is increasingly being studied for beyond these two approved uses. Researchers are examining its potential role in non-alcoholic fatty liver disease, polycystic ovary syndrome, and cardiovascular risk reduction independent of diabetes status. The SELECT trial, for instance, showed cardiovascular benefit in people with obesity but without diabetes — a finding that has expanded how clinicians and researchers think about the drug’s utility.

As a 2023 JAMA Medical News article discussed chronic weight management with semaglutide, sold under the brand names Ozempic and Wegovy, the surge in semaglutide’s popularity has brought renewed attention to how chronic weight management should be approached — not as a cosmetic concern but as a legitimate medical intervention for a condition with serious downstream consequences.

The Tradeoffs You Need to Know

No drug this effective comes without real tradeoffs, and semaglutide is no exception. The most common adverse effects are gastrointestinal — nausea, vomiting, diarrhea, and constipation — and they are documented consistently across the trial data. In the STEP 2 trial, over 63% of participants on the 2.4 mg dose reported gastrointestinal adverse events, compared to 34% in the placebo group. These effects are typically described as mild to moderate and tend to decrease over time as the body adjusts, but they’re real enough that discontinuation rates are meaningfully higher in semaglutide groups than placebo.

The 2022 meta-analysis by Tan and colleagues confirmed this pattern — while semaglutide produced that impressive 11.85% weight reduction, it also carried higher risk of gastrointestinal adverse events, treatment discontinuation, and serious adverse events compared to placebo. This isn’t an argument against the drug, but it is an argument for using it with appropriate medical oversight and realistic expectations about the adjustment period.

The 2021 safety review by Smits and Van Raalte adds important nuance: semaglutide’s overall safety profile is considered favorable, with no unexpected safety signals emerging from the extensive phase 3 trials. The authors do flag that patients at risk for diabetic retinopathy complications should be monitored carefully, and that the risk of gallbladder disease (cholelithiasis) is elevated. For the vast majority of appropriate candidates, however, the risk-benefit calculation is positive — particularly when obesity itself carries significant cardiovascular, metabolic, and mortality risk.

One underappreciated concern for men specifically: semaglutide-induced weight loss doesn’t discriminate between fat mass and lean mass. Without deliberate resistance training and adequate protein intake, a portion of the weight lost can come from muscle. If you’re using semaglutide, prioritizing strength training and hitting 1.6 to 2.2 grams of protein per kilogram of body weight daily aren’t optional extras — they’re essential protective strategies.

The Takeaway

Semaglutide is a legitimately powerful tool for two evidence-backed purposes: managing blood sugar in type 2 diabetes, and producing clinically meaningful weight loss in people with obesity. The research is unusually robust for a pharmaceutical agent, spanning multiple large-scale randomized controlled trials and systematic reviews that consistently show the same result — meaningful weight reduction with a manageable, if real, side effect profile. It isn’t magic, and it isn’t a replacement for the fundamentals of nutrition, training, and sleep. But for men struggling with obesity-related metabolic dysfunction, it represents one of the most effective pharmacological options currently available. Use it as part of a broader strategy, go in with clear eyes about the side effects, and do everything in your power to protect your muscle mass along the way.