Not medical advice. This page explains what published drug labels and studies say, in plain language. It does not tell you whether to take, start, stop, skip, or change any medicine, and it gives no doses. Those decisions belong to you and your prescriber or pharmacist.
GLP-1 medicines have gone from a niche diabetes topic to a dinner-table subject. That makes this a hard topic to read about calmly: the headlines swing between miracle and menace. This guide sticks to what the official prescribing information says for people with type 2 diabetes, what its trials found, and what it warns about, so you can show up to an appointment with sharper questions. For the broader picture of these medicines for weight and blood sugar, see our general plain-English GLP-1 guide. This page is the diabetes-specific companion.
Quick answer: GLP-1 receptor agonists are prescription medicines, mostly given by injection, that copy a gut hormone. According to the labels I read, they raise insulin release and lower glucagon in a glucose-dependent way and slow stomach emptying. In the trials reported on the semaglutide label, A1C fell, and in two outcome trials that label also reports fewer major heart events in people with established heart disease and fewer kidney and heart events in people with chronic kidney disease. Nausea, vomiting and diarrhea are the most common side effects. The labels carry a boxed warning about thyroid C-cell tumors seen in animal studies, and list warnings for pancreatitis, gallbladder disease, kidney injury from fluid loss, eye changes in people with diabetic retinopathy, low blood sugar when combined with some other diabetes medicines, and lung aspiration risk during anesthesia. Whether any of this applies to you is a decision for your prescriber and pharmacist.
This guide comes from Metabolic Clarity Labs, not from a doctor or pharmacist. It leaves out doses on purpose, it makes no recommendation about any product, and it never suggests starting, stopping or switching a medicine.
What this drug class is
GLP-1 stands for glucagon-like peptide-1, a hormone your gut releases after you eat. GLP-1 receptor agonists are medicines that activate the same receptor. The label for the semaglutide product I read (Ozempic, Novo Nordisk, revised May 2026) describes semaglutide as a GLP-1 analogue that “selectively binds to and activates the GLP-1 receptor,” stimulating insulin release and lowering glucagon in a glucose-dependent way. The label for the dulaglutide product (Trulicity, revised March 2026) describes the same family of actions and adds that it slows gastric emptying.
I also read the label for tirzepatide (Mounjaro, Eli Lilly, revised August 2026), which the label describes as a GIP and GLP-1 receptor agonist: it activates two receptors, not one. Tirzepatide is not strictly a GLP-1-only medicine, but it is often discussed with the class, and its label lists very similar warnings. Other products exist, including at least one oral GLP-1 medicine. I did not review those labels, so nothing below applies to them.
All three labels I read are for type 2 diabetes and describe the medicine as an adjunct to diet and exercise to improve glycemic control in adults. The tirzepatide and dulaglutide labels also cover patients 10 years of age and older, and each lists a heart-event risk reduction indication for particular groups. Products sold for weight management have their own labels, which I did not read here, and that topic belongs to our weight and type 2 diabetes guide.
What the trials on the label found
Labels summarize the sponsor’s trials. They are valuable primary documents, but they are company trials in defined populations, and the results are group averages, not predictions for you. The table below shows what the semaglutide label reports.
| Trial or measure (semaglutide label) | Who and how long | What the label reports |
|---|---|---|
| Monotherapy vs placebo, A1C change | 388 adults, 30 weeks | Placebo -0.1%; the two semaglutide groups -1.4% and -1.6% |
| Add-on vs sitagliptin, A1C change | 1,231 adults, 56 weeks | Semaglutide groups -1.3% and -1.5%; sitagliptin -0.7% |
| Add-on vs exenatide ER, A1C change | 813 adults, 56 weeks | Semaglutide -1.4%; exenatide ER -0.9% |
| Add-on vs insulin glargine, A1C change | 1,089 adults, 30 weeks | Semaglutide groups -1.2% and -1.5%; glargine -0.9% |
| Add-on to basal insulin vs placebo, A1C change | 397 adults, 30 weeks | Placebo -0.2%; semaglutide groups -1.3% and -1.7% |
These comparator trials were run by the sponsor, and the label does not generalize them to the whole class. Treat the A1C rows as what happened in those trials. The label does not say your A1C will drop by these amounts, and neither do I. The Endotext clinical review (Feingold, updated December 29, 2025) lists high glucose-lowering ability, no hypoglycemia on their own, weight loss and cardiovascular and heart failure benefits for the GLP-1 class in its summary tables, and notes that in the GRADE trial the GLP-1 receptor agonist liraglutide was more effective than the sulfonylurea glimepiride at keeping A1C below 7 percent. I read that chapter only in part, and I did not check the underlying GRADE paper.
Heart and kidney trials, read carefully
The semaglutide label also reports two outcome trials. In SUSTAIN 6, 3,297 adults with type 2 diabetes and established cardiovascular disease were followed for a median of 2.1 years. The main composite of cardiovascular death, non-fatal heart attack or non-fatal stroke occurred in 6.6% of people on semaglutide and 8.9% on placebo (hazard ratio 0.74, 95% confidence interval 0.58 to 0.95). In FLOW, 3,533 adults with type 2 diabetes and chronic kidney disease were followed for a median of 41 months. The kidney-and-cardiovascular composite occurred in 18.7% versus 23.2% (hazard ratio 0.76, 95% confidence interval 0.66 to 0.88).
| Outcome trial | Event rate: medicine vs placebo | Gap (my arithmetic) | What it does not tell you |
|---|---|---|---|
| SUSTAIN 6 (heart events, median 2.1 years) | 6.6% vs 8.9% | 2.3 percentage points, or about 2.3 fewer events per 100 people over that period | Whether you are in the group studied |
| FLOW (kidney and heart composite, median 41 months) | 18.7% vs 23.2% | 4.5 percentage points, or about 4.5 fewer events per 100 people over that period | Whether you have the kidney disease studied |
These trials enrolled people with specific conditions. SUSTAIN 6 required established cardiovascular disease, and FLOW required chronic kidney disease with a stated eGFR and albumin range. If you are not in those groups, the results may not describe you. A good question for your prescriber is which, if any, of the studied groups you belong to, and what your own risk profile means for the choice of medicines.
Common side effects, from the labels
Gut symptoms lead the list on every label I read. Nausea, vomiting, diarrhea, abdominal pain and constipation are listed among common reactions. Below are the figures each label reports from its own placebo-controlled trials. Do not compare rows across drugs. The trials differ in people, duration, background medicines and design, so a number in one row cannot be set against a number in another. They are shown only so you can see how the labels describe the size of the effect.
| Label and trial pool | Nausea | Vomiting | Diarrhea |
|---|---|---|---|
| Semaglutide: two placebo-controlled trials, 521 treated, mean exposure 32.9 weeks | 6.1% placebo; 15.8% and 20.3% in the two semaglutide groups | 2.3% placebo; 5% and 9.2% | 1.9% placebo; 8.5% and 8.8% |
| Tirzepatide: two placebo-controlled trials, 718 adults | 4% placebo; 12% to 18% on the medicine | 2% placebo; 5% to 9% | 9% placebo; 12% to 17% |
| Dulaglutide: placebo-controlled pool, 1,670 adults, mean exposure about 24 weeks | 5.3% placebo; 21.1% in the higher-dose group | 2.3% placebo; 12.7% | 6.7% placebo; 12.6% |
The tirzepatide label also lists decreased appetite (5% to 11% vs 1% on placebo), constipation (6% to 7% vs 1%), dyspepsia (5% to 8% vs 3%) and abdominal pain (5% to 6% vs 4%). The dulaglutide label lists abdominal pain (9.4% vs 4.9%), decreased appetite (8.6% vs 1.6%), dyspepsia (5.8% vs 2.3%) and fatigue (5.6% vs 2.6%), and says gastrointestinal reactions overall occurred in 41% of the higher-dose group versus 21% on placebo. Postmarketing reports for semaglutide include ileus, intestinal obstruction and severe constipation including fecal impaction, and the semaglutide label says it is not recommended in people with severe gastroparesis. The semaglutide label reports that about 1% of treated patients developed anti-drug antibodies, and says the neutralizing activity of those antibodies is uncertain.
The semaglutide label also says the medicine causes a delay of gastric emptying, which may affect how oral medicines are absorbed, and advises caution when oral medicines are taken at the same time. If you take other medicines, your pharmacist is the right person to ask about timing and interactions.
Serious warnings, quoted carefully
The semaglutide, tirzepatide and dulaglutide labels all open with a boxed warning about thyroid C-cell tumors. The semaglutide label says it “causes dose-dependent and treatment-duration-dependent thyroid C-cell tumors” (in rodents), and the dulaglutide label says dulaglutide causes thyroid C-cell tumors in rats. The tirzepatide label says the same for rats of both sexes. Each label says it is unknown whether this occurs in humans. All three are contraindicated in people with a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). The semaglutide label tells prescribers to counsel patients about symptoms of thyroid tumors, such as a mass in the neck, trouble swallowing, shortness of breath and persistent hoarseness, and says routine calcitonin or thyroid ultrasound monitoring is of “uncertain value” for early detection.
| Warning (from the labels I read) | What the label says | What to bring to your prescriber |
|---|---|---|
| Pancreatitis | Observed in patients treated with GLP-1 receptor agonists. Medication Guide says severe, persistent abdominal pain that may spread to the back needs prompt medical contact. | Any history of pancreas problems |
| Gallbladder disease | If gallstones or gallbladder inflammation are suspected, gallbladder studies and follow-up are indicated. | Upper abdominal pain, fever, yellowing, clay-colored stools |
| Kidney injury from fluid loss | Nausea, vomiting or diarrhea can cause volume depletion; labels advise monitoring kidney function in patients reporting such reactions. | Persistent vomiting or diarrhea, dizziness, low urine output |
| Low blood sugar with other medicines | Label says it may increase the risk of hypoglycemia, including severe, when combined with insulin or insulin secretagogues (such as sulfonylureas). | Your full diabetes medicine list |
| Diabetic retinopathy complications | Rapid improvement in glucose control has been associated with temporary worsening of diabetic retinopathy. | Eye exam history; any vision change |
| Allergic reactions | Serious hypersensitivity (anaphylaxis, angioedema) has been reported. | Prior reactions to any GLP-1 medicine |
| Lung aspiration with anesthesia or sedation | Rare postmarketing reports of pulmonary aspiration; tell providers before planned surgery or procedures. | Any planned surgery, endoscopy or sedation |
| Pregnancy and breastfeeding | Limited pregnancy data; semaglutide label notes a long washout period before planned pregnancy; no data on semaglutide in human milk. | Pregnancy plans, early |
One statement in the tirzepatide label is worth knowing about: it says the medicine may reduce the efficacy of oral hormonal contraceptives. If that applies to you, it is a question for your prescriber. The tirzepatide and dulaglutide labels also list severe gastrointestinal adverse reactions among their warnings, and the semaglutide label lists heart rate increases (a mean increase of 2 to 3 beats per minute in placebo-controlled trials) under adverse reactions.
The semaglutide Medication Guide lists symptoms that deserve a call to your healthcare provider, including severe stomach pain that will not go away, changes in vision, signs of low blood sugar such as dizziness, blurred vision, sweating, confusion and fast heartbeat, signs of dehydration, and signs of an allergic reaction such as swelling of the face, lips, tongue or throat. Severe symptoms like trouble breathing or swallowing mean emergency services.
Kidney, liver and age: what the semaglutide label says
The semaglutide label reports that kidney impairment and liver impairment did not have a clinically relevant effect on how the body handles semaglutide, and that no overall differences in safety or efficacy were detected in older patients compared with younger ones, while cautioning that greater sensitivity in some older individuals cannot be ruled out. I am repeating a statement about a specific product. It does not mean every GLP-1 product, every kidney situation, or you in particular. Ask your prescriber how your own kidney numbers and age enter the decision.
Availability, shortages, and compounded versions
Availability has been messy, and it changes. A March 20, 2025 Pharmacy Times article reported that FDA had declared the shortages of tirzepatide and semaglutide resolved, with the tirzepatide resolution affirmed in December 2024 and the semaglutide shortage listing ending around late February 2025 (dates inferred from that article’s references). The same article quotes experts raising concerns about compounded versions, saying they are not approved by regulators, that FDA told compounders they had a transition period to stop production once shortages ended, and that some patients may face problems switching from compounded to approved products because the contents of compounded products are unknown. I could not open FDA’s own page on this topic, and I did not find a current shortage list, so check with your pharmacist for what is true today.
I have no price claims for this guide. Prices, coverage and prior-authorization rules vary by plan and change often. Ask your pharmacy and insurer.
How glucose tracking fits in
Whatever medicines you use, a log of your own numbers and symptoms helps your care team. Our guide to reading CGM data and the post-meal glucose tracker show how to keep a clean record. A useful log for these medicines might include dates, meals, glucose readings, nausea or vomiting episodes, and any vision changes or severe stomach pain. Bring it to your prescriber, because they are the right person to interpret it and decide whether anything about your medicines should change. A CGM can also reveal low readings, which matters if you take insulin or a sulfonylurea alongside a GLP-1 medicine, as the labels warn.
Food and movement still matter. The labels frame these medicines as adjuncts to diet and exercise. Our diabetes food guide and diets compared page cover eating patterns, and our plain-language metformin guide covers the other medicine people most often ask about.
How to read your own medicine label
You do not need a medical degree to find the useful parts of a prescribing label, and reading yours before an appointment makes the visit more productive. Search for your product on DailyMed or on FDA’s Drugs@FDA site, and check the revision date at the top, because labels change. The first page, called the highlights, shows the boxed warning if there is one, the indications (what the medicine is approved for and in whom), the contraindications (who should not use it) and a short list of warnings.
Further in, look for the adverse reactions section, which holds the tables I summarized above, and for the clinical studies section, which describes who was enrolled, how long the trials ran and what was measured. Always ask who the trial population was, because results describe the people studied. The Medication Guide at the end is written for patients, in plainer language, and is a good place to find the symptoms that should prompt a call. If something on the label does not make sense, write it down and ask your pharmacist, who is trained to explain it.
Two habits help. First, read the label for the exact product you are prescribed, not a different product in the same class. Second, treat a label as a snapshot: if your prescriber changes your product, read the new one.
Questions to bring, by situation
These are prompts, not instructions.
If a GLP-1 medicine has been suggested for you
Why this medicine for me, and what is the goal? Which of the studied groups, if any, do I fit (heart disease, kidney disease)? What side effects should I expect and when should I call? Which of my current medicines interact? How will we know whether it is working?
If you take insulin or a sulfonylurea
The labels warn about a higher risk of low blood sugar with these combinations. What should I watch for, what is the plan if I have a low, and who adjusts my other medicines?
If you have eye disease, pancreatitis or gallbladder history
The labels list diabetic retinopathy complications, pancreatitis and gallbladder disease. How does my history change the conversation, and how often should my eyes be checked?
If you have kidney disease, or vomiting and diarrhea
Nausea, vomiting and diarrhea can lead to fluid loss, which the labels link to kidney injury. What is my sick-day plan? Who should I call, and how quickly?
If you are planning surgery or a procedure with sedation
The labels mention aspiration risk with anesthesia and deep sedation. Who needs to know I take this medicine, and who decides what happens around the procedure?
If you could become pregnant, are pregnant or are breastfeeding
The labels discuss pregnancy and, for tirzepatide, oral contraceptives. What is the plan before conception and during pregnancy, and which products are discussed for those situations?
If you saw an online offer or a “natural” alternative
Ask your prescriber before buying anything. A supplement is not a replacement for a prescribed medicine, and compounded products are not FDA-approved. For what is and is not known about one popular claim, see our existing berberine and “nature’s Ozempic” page and berberine and metformin. Neither is a reason to change a prescription.
Common mistakes
Reading class-wide claims as product-specific. A statement on one label is about that product. Ask which product is being discussed.
Comparing side effect percentages across labels. Different trials, different populations. The table above says so for a reason.
Treating outcome-trial results as a promise. SUSTAIN 6 and FLOW enrolled specific high-risk groups.
Ignoring low-blood-sugar risk when combined with other medicines. The labels name insulin and insulin secretagogues.
Not telling anyone before surgery or sedation. The labels ask you to inform your providers.
Assuming a compounded or online version is the same product. The experts quoted in Pharmacy Times say compounded versions are not approved and their contents are unknown.
Making changes on your own. Nothing here is a reason to start, stop, skip or switch anything. Talk to your prescriber first.
Myth versus fact
Myth: These medicines are just for weight loss. Fact: The labels I read are for type 2 diabetes, as adjuncts to diet and exercise; weight-management products have separate labels.
Myth: The thyroid warning means they cause thyroid cancer in people. Fact: The boxed warning is based on rodent studies. The labels say whether it occurs in humans is unknown, and the medicines are contraindicated in people with a personal or family history of MTC or MEN 2.
Myth: Every GLP-1 product is the same. Fact: Each has its own label, trials and details. Tirzepatide acts on two receptors.
Myth: A supplement works like a prescription GLP-1. Fact: Supplements do not have the trial programs summarized on these labels, and nothing here supports swapping one for the other.
Myth: If one trial found fewer heart events, every user gets that benefit. Fact: The trials studied specific groups, and group results do not guarantee individual outcomes.
Twelve questions to ask your prescriber or pharmacist
- Which specific product are we discussing, and why that one for me?
- What is the goal, and how will we judge whether it is working?
- Which studied group (heart disease, kidney disease) do I fit, if any?
- Which of my current medicines interact or raise the risk of low blood sugar?
- What side effects should I expect, and when should I call?
- What is my plan for vomiting, diarrhea or dehydration?
- How does my eye, pancreas, gallbladder or thyroid history change this?
- Who needs to know before surgery, endoscopy or sedation?
- If I could become pregnant, what should I know now?
- What do labs, eye exams and check-ins look like while I am on it?
- How should I think about compounded or online versions?
- What should I bring to the next visit?
Frequently asked questions
What are GLP-1 medicines for type 2 diabetes?
Prescription medicines that activate the GLP-1 receptor. The labels I read describe them as adjuncts to diet and exercise to improve glycemic control in adults with type 2 diabetes. Some labels also list heart-event risk reduction in specific groups.
How do they work?
The semaglutide label says it activates the GLP-1 receptor, stimulating insulin release and lowering glucagon in a glucose-dependent way. The dulaglutide label also describes slowed gastric emptying. Tirzepatide acts on both GIP and GLP-1 receptors.
What are the common side effects?
Nausea, vomiting, diarrhea, abdominal pain and constipation lead the labels. For example, the semaglutide label reports nausea in 15.8% and 20.3% of the two treated groups vs 6.1% on placebo in two trials. Do not compare percentages across different drugs.
What does the thyroid boxed warning mean?
The labels say the medicines cause thyroid C-cell tumors in rodents, and that it is unknown whether this occurs in humans. They are contraindicated in people with a personal or family history of medullary thyroid carcinoma or MEN 2. Ask your prescriber how your history applies.
Can they cause low blood sugar?
The labels say they may increase the risk of hypoglycemia, including severe hypoglycemia, when combined with insulin or insulin secretagogues. Ask your prescriber about your own combination.
Do they affect the kidneys?
The labels warn that nausea, vomiting and diarrhea can cause fluid loss and acute kidney injury, and advise monitoring kidney function. The semaglutide label also reports a kidney outcomes trial in people with type 2 diabetes and chronic kidney disease. Ask what applies to you.
Should I tell my surgeon or anesthesiologist?
The labels list rare postmarketing reports of pulmonary aspiration during general anesthesia or deep sedation and ask patients to tell providers before planned procedures. Your care team decides what to do.
Are compounded versions the same?
Experts quoted by Pharmacy Times in March 2025 said compounded versions are not approved by regulators and that their contents are unknown. Ask your pharmacist about current rules.
Can a supplement replace a GLP-1 medicine?
This page does not support that. Supplements do not have the trial programs summarized on these labels. See our berberine pages and talk to your prescriber.
How is this different from metformin?
They are different medicines with different labels, mechanisms and warnings. See our plain-language metformin guide. Which one, if either, fits your situation is a prescriber decision.
Sources
- FDA label: Ozempic (semaglutide) injection, Novo Nordisk, revised May 2026
- FDA label: Mounjaro (tirzepatide) injection, Eli Lilly, revised August 2026
- FDA label: Trulicity (dulaglutide) injection, revised March 2026
- Feingold KR, Oral and Injectable (Non-Insulin) Pharmacological Agents for the Treatment of Type 2 Diabetes, Endotext (updated December 29, 2025)
- Pharmacy Times (March 20, 2025): concerns surrounding compounded GLP-1s as shortages end
I could not open MedlinePlus, NIDDK, FDA’s own compounding page, or the ADA Standards of Care, so I did not quote them. I read the labels through a summarizing tool, not line by line, so check the current label for your own product. Labels change often.
About the author: Charles Kirkland is the founder of Metabolic Clarity Labs and author of The Journey Back. He is not a physician. This is general education, not a medically reviewed treatment plan.
Sources checked October 31, 2026. Discuss personal decisions with a qualified clinician. Do not start, stop, or change prescribed treatment based on this article.
Leave a Reply