Mayo Clinic Proceedings puts GI side-effect rates at 40-70% and makes diet the first-line response

A clinical review published in Mayo Clinic Proceedings and aimed at primary care physicians reports that 40% to 70% of patients taking GLP-1 and GIP receptor agonists experience gastrointestinal adverse effects, and recommends that management begin with dietary modification rather than medication ^[1].

The paper, titled "GLP1 and GIP Receptor Agonists: Effects on the Gastrointestinal Tract and Management Strategies for Primary Care Physicians," frames stomach and bowel symptoms as the most common practical problem clinicians face with this drug class, and lays out a first step that does not involve prescribing anything new ^[1].

What the review recommends first

According to the review, the opening move for gastrointestinal complaints is dietary: smaller, more frequent meals, adequate hydration, and avoiding high-fat or high-sugar foods ^[1]. That advice is directed at the physicians who manage these prescriptions day to day, and it reflects how closely the side effects of this drug class are tied to how the gut handles food.

GLP-1 receptor agonists include semaglutide, sold as Ozempic and Rybelsus for type 2 diabetes and as Wegovy for weight management. Tirzepatide, sold as Mounjaro and Zepbound, acts on both the GLP-1 and GIP receptors. The review covers this class as a group ^[1].

The 40% to 70% range is wide, and the sources available here do not break it down by individual drug, by dose, by how long someone has been taking the medication, or by how severe the symptoms were. The review's full methods — whether the figure comes from pooled clinical trial data, observational studies, or a mix — are not available in the material provided. Which specific symptoms are counted inside that range, such as nausea, vomiting, diarrhea or constipation, is also not spelled out in what is available.

What can be said is that a range that broad still points in one direction: gastrointestinal effects are common, not rare, and common enough that a journal read by general practitioners considered it worth publishing a management guide ^[1].

Why it matters for patients

Gastrointestinal side effects are one of the main reasons people stop taking GLP-1 medications, and they are also the symptoms most likely to show up in the first weeks of treatment or after a dose increase. A review telling primary care doctors that 40% to 70% of patients will experience them sets an expectation: if you feel sick on these drugs, you are not unusual ^[1].

The second practical point is about sequencing. The review positions diet as the starting response — smaller and more frequent meals, staying hydrated, and steering away from high-fat and high-sugar foods — before other interventions ^[1]. For a patient, that means a doctor who responds to a complaint about nausea with questions about meal size and fluid intake is following what this review advises, not brushing the problem off.

It also matters because primary care is where most of these prescriptions are now managed. Guidance written specifically for that audience tends to shape what happens in a 15-minute appointment more than specialist literature does.

What this review does not do, based on what is available, is tell patients when symptoms cross from expected to concerning, or what the next step is when diet changes are not enough. Those details may be in the full paper but are not in the sources here. Severe, persistent or worsening symptoms are a matter for a clinician, and nothing in this review changes that.

What happens next

The review was published in Mayo Clinic Proceedings with a 2025 article identifier ^[1]. Reviews like this one do not carry the force of a formal guideline from a professional society or the Food and Drug Administration; they are guidance that individual clinicians may or may not adopt. Whether the diet-first approach described here gets picked up in future society guidance is not addressed in the available sources.

Patients who want the specifics can ask their prescriber whether they follow this approach, and what the plan is if dietary changes do not settle the symptoms.