Short answer: In the label's placebo-controlled trials, the most common Trulicity side effects were nausea (12.4% on 0.75 mg and 21.1% on 1.5 mg vs 5.3% on placebo), diarrhea (8.9% and 12.6% vs 6.7%), vomiting (6.0% and 12.7% vs 2.3%), stomach pain, decreased appetite, indigestion and fatigue. Trulicity has a boxed warning about thyroid C-cell tumors.
What Trulicity is approved for: Trulicity is approved, along with diet and exercise, to improve blood sugar control in adults and children 10 years and older with type 2 diabetes, and to lower the risk of major heart and blood vessel events in adults with type 2 diabetes who have heart disease or several heart risk factors (section 1).
Source
TRULICITY (dulaglutide) injection, prescribing information and Medication Guide. Eli Lilly. DailyMed, version published August 10, 2026. DailyMed setid 463050bd-2b1c-40f5-b3c3-0a04bb433309
WARNING: RISK OF THYROID C-CELL TUMORS
In rats, dulaglutide caused thyroid C-cell tumors after lifetime exposure. It is not known whether Trulicity causes these tumors, including medullary thyroid carcinoma (MTC), in people. Trulicity must not be used by anyone with a personal or family history of MTC or with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).
These are the label's own numbers from the Adverse Reactions section. Where the label compares with placebo (a dummy treatment), both columns are shown, so you can see how much more often a reaction happened on Trulicity.
| Adverse reaction | Placebo (N=568) % | Trulicity 0.75 mg (N=836) % | Trulicity 1.5 mg (N=834) % |
|---|---|---|---|
| Nausea | 5.3 | 12.4 | 21.1 |
| Diarrhea | 6.7 | 8.9 | 12.6 |
| Vomiting | 2.3 | 6.0 | 12.7 |
| Abdominal Pain | 4.9 | 6.5 | 9.4 |
| Decreased Appetite | 1.6 | 4.9 | 8.6 |
| Dyspepsia | 2.3 | 4.1 | 5.8 |
| Fatigue | 2.6 | 4.2 | 5.6 |
1,670 adults with type 2 diabetes on Trulicity for a mean of 23.8 weeks. Diarrhea includes larger or more frequent bowel movements; vomiting includes retching; abdominal pain includes discomfort and tenderness; fatigue includes weakness and malaise. Hypoglycemia is reported separately.
| Adverse reaction | Trulicity 1.5 mg (N=612) % | Trulicity 3 mg (N=616) % | Trulicity 4.5 mg (N=614) % |
|---|---|---|---|
| Nausea | 13.4 | 15.6 | 16.4 |
| Diarrhea | 7.0 | 11.4 | 10.7 |
| Vomiting | 5.6 | 8.3 | 9.3 |
| Dyspepsia | 2.8 | 5.0 | 2.6 |
1,842 adults taking the higher doses as an add-on to metformin. No placebo group in this trial.
Stomach and gut reactions overall: placebo 21%, 0.75 mg 32%, 1.5 mg 41%. Stopping because of them: 1.3% and 3.5% vs 0.2% on placebo. Investigators graded most as mild (58% and 48%) or moderate (35% and 42%); 7% and 11% were severe.
Less common gut reactions (placebo; 0.75 mg; 1.5 mg): constipation 0.7%, 3.9%, 3.7%; gas 1.4%, 1.4%, 3.4%; bloating 0.7%, 2.9%, 2.3%; acid reflux 0.5%, 1.7%, 2.0%; burping 0.2%, 0.6%, 1.6%.
Fast heart rate (sinus tachycardia): 3.0% on placebo, 2.8% on 0.75 mg and 5.6% on 1.5 mg. First-degree AV block: 0.9%, 1.7% and 2.3%.
Injection site reactions such as rash or redness: 0.5% on Trulicity vs 0.0% on placebo in adults. Systemic allergic reactions, sometimes severe: 0.5% of adults.
Low blood sugar was more frequent with a sulfonylurea or insulin: under 54 mg/dL in 20% and 21% of people with a sulfonylurea (0.75 mg and 1.5 mg) in a 78-week trial.
The Warnings and Precautions part of the label lists these. Each line gives the label's heading and what it means in plain words.
Risk of thyroid C-cell tumors. The boxed warning risk. One case of MTC was reported in a Trulicity trial, in a person whose calcitonin was already about 8 times the upper limit of normal before treatment.
Acute pancreatitis. Inflammation of the pancreas, including fatal cases, has been seen with this drug class, including Trulicity. If it is suspected, Trulicity is stopped.
Low blood sugar with insulin or sulfonylureas. Using Trulicity with insulin or a sulfonylurea raises the risk of low blood sugar, including severe episodes. Lowering the dose of those medicines may reduce the risk.
Serious allergic reactions. Anaphylaxis and angioedema have been reported after approval. If one happens, Trulicity is stopped.
Kidney injury from fluid loss. Kidney injury, sometimes needing dialysis, has been reported, mostly after fluid loss from nausea, vomiting or diarrhea.
Severe stomach and gut reactions. Gut side effects can be severe. Trulicity is not recommended for people with severe gastroparesis.
Diabetic eye disease. In a heart outcomes trial (median 5.4 years), diabetic eye complications happened in 1.9% on Trulicity 1.5 mg vs 1.5% on placebo, and in 8.5% vs 6.2% of people with a history of retinopathy. Fast blood sugar improvement can temporarily worsen retinopathy; people with a history of it should be monitored.
Gallbladder disease. Gallstones and gallbladder inflammation have been reported with this drug class. If gallstones are suspected, the label calls for gallbladder tests.
Breathing in stomach contents during anesthesia. Trulicity slows stomach emptying. Rare cases of pulmonary aspiration under general anesthesia or deep sedation have been reported with this drug class; tell the care team before any procedure.
From the Medication Guide that comes with Trulicity:
Dose Track has a side-effect log. Each entry records the symptom, a severity (none, mild, moderate, severe or life-threatening), the date and an optional note, and can be tied to a specific dose or logged on its own. The history screen shows what you logged over time, which makes it easier to tell your prescriber when a reaction started and whether it is easing. The app records what you enter; it does not judge whether a symptom is serious. For anything on the label's call-your-doctor list, call your doctor.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.