The Changing Science of GLP-1 Medications

It seems like only yesterday that Ozempic and Wegovy became household names. In truth, it was several years ago, but the science surrounding GLP-1 medications is moving so quickly that even last year’s information has become outdated.

During the past year, since we last wrote about these groundbreaking drugs, new medications have been approved, more powerful versions have moved closer to market, and researchers have uncovered additional health benefits that may go beyond the positive impact of losing weight. At the same time, we’re learning more about some potentially serious side effects, and the booming market for unapproved versions of these drugs has raised new safety concerns.

For the millions of Americans taking GLP-1 medications to manage type 2 diabetes or obesity, there’s a lot to catch up on.

First, a Refresher: How Do GLP-1s Work?

It’s all about hormones. Our bodies produce a variety of hormones that help regulate digestion, blood sugar, and appetite. One of them is glucagon-like peptide-1, or GLP-1, which is released by the intestines after we eat.

GLP-1 sends messages to several parts of the body. It tells the pancreas to release insulin when blood sugar rises, suppresses the release of another hormone called glucagon when it isn’t needed, slows the movement of food out of the stomach, and communicates with the brain to help us feel satisfied after eating.

In people with type 2 diabetes, the body has trouble responding properly to insulin, and the pancreas may eventually struggle to produce enough of it. GLP-1 medications help the pancreas release insulin when glucose levels are elevated and reduce inappropriate glucagon secretion, improving blood sugar control.

Most important to many are the ways these medications affect appetite. They act on the brain’s appetite-regulating pathways, helping people feel full sooner, stay satisfied longer, and experience fewer persistent thoughts about food. The medications don’t simply make people too nauseated to eat, although nausea can certainly be an unwelcome side effect. They actually change the biological signals that influence hunger and satiety. They do this by activating receptors to the hormones that make us feel full (satiety hormones) and mimicking their effects. This is why these drugs are known as GLP-1 receptor agonists.

Semaglutide, the active ingredient in Ozempic and Wegovy, mimics GLP-1. Tirzepatide, sold as Mounjaro and Zepbound, activates receptors for both GLP-1 and another satiety hormone called GIP. Activating both pathways appears to produce greater average weight loss than targeting GLP-1 alone.

And now researchers are developing medications that target additional satiety hormone pathways, with the hope of producing even better results.

The New Generation: More Pills, More Hormones, More Weight Loss

One of the biggest developments this year is the arrival of more oral options.

In December 2025, the FDA approved an oral version of Wegovy for weight management. Oral semaglutide was already available as Rybelsus for type 2 diabetes, but the new approval expanded the options for people seeking obesity treatment without injections.

Then, in April 2026, the FDA approved Foundayo, a once-daily pill containing orforglipron. Unlike semaglutide, which is a peptide-based drug, orforglipron is a small molecule that activates the GLP-1 receptor. That distinction matters because it can be taken without the strict empty-stomach requirements associated with oral semaglutide.

Clinical trials have shown meaningful weight loss, although the most effective injectable medications generally produce greater average reductions. The advantage is convenience, particularly for people who would prefer to avoid injections.

Meanwhile, injectable medications are becoming more potent. In March, the FDA approved a higher-dose version of Wegovy, allowing certain adults to receive 7.2 milligrams weekly rather than the previous maximum weight-management dose of 2.4 milligrams.

And there are several promising medications still making their way through clinical trials.

Retatrutide, developed by Eli Lilly, targets three hormone receptors: GLP-1, GIP, and glucagon. Glucagon normally raises blood sugar, but activating its receptor as part of this particular drug combination may also increase energy expenditure and influence how the body processes fat. Recent phase 3 research has demonstrated substantial weight loss. It’s an exciting development, but retatrutide is still investigational, and its long-term safety profile is not yet fully established.

Novo Nordisk’s CagriSema takes a different approach. It combines semaglutide with cagrilintide, which mimics amylin, another hormone that helps regulate appetite and fullness. Recent trial results suggest the combination can produce considerable weight loss. It is also still awaiting regulatory approval.

Amgen is studying MariTide, an experimental medication that activates GLP-1 receptors while blocking GIP receptors. Interestingly, that’s the opposite GIP strategy from tirzepatide. Researchers are exploring whether its long-lasting action could eventually allow monthly dosing rather than weekly injections.

The common theme is that researchers are finding more ways to influence the complex hormonal systems that control appetite, metabolism, and blood sugar. But more powerful drugs may also bring more pronounced side effects, and impressive weight-loss numbers are only one part of determining whether a medication is safe and useful.

Are GLP-1s Doing More Than Helping People Lose Weight?

This may be the most intriguing development in the research.

We already know that losing excess weight can improve blood pressure, cholesterol, blood sugar control, sleep apnea, and reduce many cancer risks. So, when someone taking a GLP-1 medication loses 15 or 20 percent of their body weight and becomes healthier, that’s not necessarily surprising.

The more interesting question is whether the medication itself provides health benefits beyond those produced by losing weight.

Increasingly, the answer appears to be yes, at least for some conditions.

Consider cardiovascular disease. In a large clinical trial called SELECT, researchers followed more than 17,000 adults with overweight or obesity and established cardiovascular disease, but without diabetes. Participants taking semaglutide experienced a 20 percent relative reduction in major cardiovascular events, including heart attack, stroke, and cardiovascular death.

That finding was important on its own. But subsequent analyses revealed something even more interesting: cardiovascular benefits appeared before participants had lost substantial amounts of weight, and benefits were observed across different levels of weight loss.

Researchers are now examining several possible explanations. GLP-1 medications appear to influence inflammation, blood vessel function, blood sugar regulation, and other processes involved in cardiovascular disease. Some of these effects may occur independently of weight reduction.

A 2026 scientific review suggested that a meaningful portion of the cardiovascular protection associated with GLP-1 medications may not be explained by weight loss alone. However, these estimates come from statistical analyses, not experiments that can definitively separate the drug’s direct effects from the consequences of losing weight.

The distinction matters. It suggests that these medications may eventually have a role in treating certain conditions even when weight loss isn’t the primary objective. But it is way too early to guess if that will be the case.

Kidney disease is another area of considerable interest. Clinical trials have shown that semaglutide can reduce the progression of kidney disease and lower cardiovascular risk in certain patients with type 2 diabetes and chronic kidney disease. Researchers suspect that improved blood sugar, lower blood pressure, reduced inflammation, and other mechanisms all contribute.

Scientists are even exploring whether these drugs might influence addiction, cognitive decline, and neurodegenerative diseases. These findings have generated considerable excitement, but much of the evidence remains preliminary or mixed. An association in a large medical-record study is not the same as proof that a medication prevents dementia or treats addiction.

In other words, GLP-1 medications may eventually prove useful for considerably more than diabetes and obesity. But we’re not yet at the point where anyone should be taking one for anything other than diabetes and/or weight loss.

The Other Side of the Story: New Concerns About Side Effects

As the number of people taking this class of medications has increased, so has our information about potential negative side effects. Because they work so well for weight loss and diabetes, many patients struggling with those conditions embraced these medications before their long-term effects were defined and studied. In many ways, GLP-1 patients are part of a giant, ongoing longitudinal study, which continuously produces new insights into a range of side effects.

The familiar side effects haven’t gone away. Nausea, vomiting, constipation, diarrhea, and abdominal discomfort remain common, particularly when patients first begin treatment or increase their dose. Gradually increasing the dose helps many people tolerate the medications.

More serious problems, including gallbladder disease, pancreatitis, dehydration-related kidney injury, and severe gastrointestinal complications, are less common but require attention.

Over the past year, researchers have also been examining some less familiar problems.

Vision changes. One of the most concerning findings involves a rare eye condition called nonarteritic anterior ischemic optic neuropathy, or NAION. It occurs when blood flow to the optic nerve is disrupted, potentially causing sudden and sometimes permanent vision loss.

A 2026 analysis combining results from multiple studies found an association between GLP-1 medications and an increased risk of NAION. However, other analyses, including those focused on randomized clinical trials, have produced less definitive results.

The condition is rare, and diabetes, obesity, and cardiovascular disease are themselves associated with eye problems. That makes it difficult to determine how much of the observed risk is caused by the medication rather than the underlying health conditions of the people taking it.

The concern is credible enough to take seriously, but not a reason for most patients to abandon a beneficial medication. Sudden changes in vision should always be evaluated urgently.

Hair, skin, and nails. Dermatologists are seeing more patients who report hair thinning, changes in skin appearance, and brittle nails while taking GLP-1 medications.

Some of these changes have a fairly straightforward explanation. Rapid weight loss can temporarily disrupt the normal hair-growth cycle, causing a condition called telogen effluvium. Eating significantly less can also make it harder to consume enough protein, iron, and other nutrients needed to maintain healthy hair, skin, and nails.

Weight loss also reduces facial fat, which can make wrinkles and loose skin more noticeable. The much-discussed “Ozempic face” is largely a consequence of losing facial volume, not evidence that the medication is directly damaging the skin.

But recent research suggests the hair-loss question may be more complicated. A 2026 study comparing people taking GLP-1 medications with those using other diabetes drugs found a higher relative incidence of alopecia, although the absolute risk remained low. Researchers are still trying to determine whether the medications themselves contribute to hair loss beyond the effects of weight reduction.

Evidence connecting these drugs directly to brittle nails or other nail disorders is much weaker. For now, inadequate nutrition and rapid weight loss remain important possible explanations.

Muscle loss. Another concern is the loss of lean tissue during substantial weight reduction. When people lose weight, they generally lose a combination of fat and lean mass. This isn’t unique to GLP-1 medications, but the amount and speed of weight loss make it especially important to preserve muscle.

Adequate protein, resistance exercise, and appropriate medical monitoring can help protect strength and function during treatment. And some of the formulations pending approval claim to help prevent muscle loss.

A Word About Compounded and Unapproved Drugs

As demand for GLP-1 medications has grown, so has the market for compounded versions, online prescriptions, and products advertised as alternatives to approved drugs.

Compounding can serve a legitimate medical purpose when an individual patient needs a medication that isn’t commercially available in a suitable form. But compounded medications are not FDA-approved, and the agency does not independently review their safety, effectiveness, or manufacturing quality before they are marketed.

Federal restrictions on routinely compounding copies of commercially available GLP-1 medications have also tightened as shortages have resolved. The FDA has raised concerns about dosing errors, inconsistent quality, and misleading marketing. There is a huge difference between working with a trusted medical provider to secure compounded medications and filling out an online questionnaire sent by an organization marketing “lifestyle medicines.”

Even more troubling is the online sale of investigational drugs such as retatrutide and cagrilintide, sometimes advertised as compounded medications or “research peptides.”

Neither substance is approved by the FDA, and the agency has explicitly stated that they cannot legally be used in compounding under federal law.

The fact that a medication is being studied in a clinical trial does not mean it is safe to purchase from an online seller. There is a considerable difference between receiving an experimental medication under carefully controlled research conditions and injecting something purchased from a website.

Patients should always discuss the source, formulation, and safety of their medication with a qualified healthcare provider.

What About Long-Term Use?

One of the most important lessons from the past several years is that obesity is a chronic medical condition, and GLP-1 treatment often needs to be approached the same way.

These medications change the hormonal signals that regulate appetite and metabolism while they’re being taken. When treatment stops, those effects diminish, and many people experience a return of hunger and regain some or much of the weight they lost.

That doesn’t mean the medication failed. It means the biological processes that contributed to weight gain are still operating.

New research is exploring whether patients can transition from injections to oral medications, use different maintenance doses, or combine medication with lifestyle interventions to preserve their results. But there is no established strategy that guarantees weight maintenance after discontinuation.

The decision to begin treatment should therefore include a discussion about long-term affordability, insurance coverage, side effects, and what happens if the medication becomes unavailable.

Not everyone is an appropriate candidate. People with a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia syndrome type 2 should not use medications carrying those contraindications. Pregnancy, certain serious gastrointestinal conditions, and other individual medical risks also require careful evaluation.

And if you’re planning a procedure involving anesthesia or deep sedation, make sure your medical team knows you’re taking a GLP-1 medication. Current guidance is more individualized than the old blanket recommendation to stop injections a week beforehand. Many patients can continue treatment, while those at higher risk of delayed stomach emptying may need additional precautions.

The Bottom Line

GLP-1 medications have already transformed the treatment of type 2 diabetes and obesity. Now we’re learning that their potential benefits may extend to the heart, kidneys, and other organs, sometimes through mechanisms that go beyond weight loss.

But we’re also learning that these powerful medications affect multiple systems in the body, and there is still much we don’t know about their long-term effects.

The growing number of options is encouraging. Pills may make treatment more convenient, new combinations may make it more effective, and ongoing research may identify additional patients who could benefit.

The goal, however, isn’t simply to lose the most weight in the shortest time. It’s to improve long-term health while minimizing risks.

If you’re considering a GLP-1 medication, already taking one, or wondering whether a newer option might be right for you, talk with your Amaze medical team. We can help you evaluate the benefits, risks, medication options, and practical considerations based on your individual health history.