Over the past several years, a class of medications that activate the glucagon-like peptide 1 receptor, commonly called GLP-1 receptor agonists, has reshaped how researchers and clinicians think about type 2 diabetes and obesity. A newer agent, tirzepatide, goes one step further by activating a second receptor, the glucose-dependent insulinotropic polypeptide receptor, creating what scientists call a dual agonist. Both approaches lower blood glucose, reduce body weight, and in published trials have shown benefits for the heart and kidneys.
Yet a review published in Nature Reviews Endocrinology points to a quieter side of the story. Real-world data from the past two years suggest that a large share of people who start these medications stop them, often within the first twelve months. The review, authored by Ceriello and colleagues, asks two connected questions: why do people discontinue, and what does discontinuation actually do to cardiometabolic health over time?
The answers, the authors argue, have serious implications for how long-term diabetes care and weight management should be planned. This article summarizes their findings in plain terms.
How these medications work
To understand why stopping matters, it helps to understand what these drugs are doing while a person is on them. GLP-1 receptor agonists mimic a hormone the gut naturally releases after eating. That hormone signals the pancreas to release insulin when blood sugar rises, tells the liver to slow glucose production, and sends satiety signals to the brain. The result is lower blood sugar and, over time, meaningful reductions in body weight.
Tirzepatide adds activation of a second gut hormone receptor. Early and ongoing trial data suggest this dual mechanism produces even larger reductions in blood glucose and body weight compared with single-receptor agonists. Both drug classes also appear to reduce inflammation in blood vessel walls and support cardiovascular health through several pathways, though the review notes that the precise anti-atherosclerotic mechanisms are still being studied.
Why people stop
The review identifies several recurring reasons why patients discontinue these medications, drawing on real-world adherence data. Gastrointestinal side effects top the list. Nausea, vomiting, and related symptoms are common early in treatment and, for a meaningful proportion of users, are severe enough to prompt stopping entirely.
Cost is a second major barrier. Both drug classes carry high list prices in many markets, and insurance coverage varies widely. When coverage lapses or cost-sharing rises, patients frequently discontinue regardless of how well the medication was working.
A third reason is perceived lack of efficacy. Not every person achieves the dramatic weight or blood sugar results that clinical trials headline. When results feel disappointing relative to expectations, or when weight loss plateaus, some patients and their prescribers decide to stop.
Finally, the review notes that fear about uncommon or rare adverse effects, often amplified by media coverage, leads some patients to discontinue preemptively even without personally experiencing a problem. The authors are careful to note that many of these feared effects remain uncommon in the published trial data, but perception shapes behavior regardless.
Weight regain after stopping
The most immediately visible consequence of discontinuation, according to the review, is weight regain. Because these medications suppress appetite through receptor-level signaling, removing that signal allows appetite to return, often to levels that feel higher than before treatment. Published data consistently show that a substantial portion of the weight lost during therapy returns once therapy ends.
This is not simply an aesthetic concern. Excess body weight is itself a risk factor for cardiovascular disease, type 2 diabetes progression, and a range of other conditions. The review frames weight regain not as a failure of willpower but as a predictable pharmacological consequence of stopping a drug that was actively suppressing biological hunger signals.
Glucose control and HbA1c fluctuation
For people with type 2 diabetes, stopping these medications also means losing active glycemic control. Blood glucose levels rise, and HbA1c, a measure of average blood sugar over roughly three months, climbs back toward pre-treatment values. The review highlights that repeated cycles of starting, stopping, and restarting therapy could produce oscillating HbA1c levels over time.
The authors flag this oscillation as a concern in its own right. Research in diabetes care has linked fluctuating blood sugar control, as opposed to steady control even at a somewhat elevated level, to higher rates of microvascular complications including damage to the eyes, kidneys, and nerves. Consistent control, the literature suggests, matters not just for the average number but for how stable that number is over months and years.
Cardiovascular risk around discontinuation
Perhaps the most striking section of the review addresses the cardiovascular implications of stopping these drugs. While the medications are on board, they appear to provide multiple layers of protection: lower glucose, lower body weight, reduced inflammation, and possibly direct effects on arterial plaques. When they are stopped, all of those effects reverse.
The review raises a specific concern about plaque stability. Atherosclerotic plaques, the fatty deposits that build up inside artery walls, can be more or less vulnerable to rupture depending on their composition and the inflammatory environment around them. The incretin-based medications appear to support plaque stabilization through anti-inflammatory pathways. Removing that support, especially suddenly, might leave plaques in a more vulnerable state, at least temporarily.
The authors are careful to acknowledge the limits of current evidence here. They note that few published studies have directly measured hard cardiovascular outcomes, such as heart attacks or strokes, specifically in the period immediately following discontinuation. The concern is grounded in mechanistic reasoning and early observational signals, not yet in large randomized trial data. Still, the review argues that this gap in the evidence deserves serious research attention.
Long-term implications for care planning
The review closes by reframing the discontinuation problem as a care-planning problem. If clinicians and patients treat these medications as short-term tools rather than long-term therapies, the review argues, the pattern of starting and stopping may itself generate cardiometabolic risk that offsets some of the benefit gained during active treatment.
The authors call for better strategies to improve persistence on therapy. That includes more aggressive management of gastrointestinal side effects early in treatment, clearer patient education about the expected course of benefits, policy efforts to reduce cost barriers, and follow-up research to understand what happens biologically in the weeks and months after stopping.
For researchers studying metabolic peptides more broadly, the review reinforces a growing theme in the literature: that the timing, continuity, and context of receptor-level signaling matters as much as the peak effect of any single agent. Incretin pathways do not operate in isolation, and the consequences of withdrawing their activation ripple through glucose metabolism, body weight regulation, vascular biology, and inflammatory signaling simultaneously.
The literature on GLP-1 receptor biology and related metabolic peptides continues to grow rapidly. This review adds an important dimension by focusing not on what these molecules do when present, but on what the body does when they are taken away.
