Is Tirzepatide Safe? Trial Data, FAERS Reports, Compounded Risks
Tirzepatide has been FDA-approved since 2022 and was tested in 19,884 people across 8 major trials. Its label carries a boxed warning for thyroid C-cell tumors and 9 other warnings. 2 groups should not take it.
- FDA-approved since
- 2022
- People in its major trials
- 19,884
- Boxed warning
- Thyroid C-cell tumors
Key facts about Zepbound
Half-life 5 to 6 days: after 5.5 d, half remains, and about 3% is still present after five half-lives (27.5 d).
In SURMOUNT-1 over 72 weeks, the reported body-weight loss was 20.9%, versus 3.1% with placebo.
Monthly prices in US dollars include the list price and self-pay offers, each taken from the maker's price page.
Sources: FDA label (DailyMed), Eli Lilly 1 2, cnbc.com.
Boxed warning
Boxed warning: it caused thyroid C-cell tumors in rodents; whether it causes them in people is not known. Do not take this medicine if your personal or family history includes medullary thyroid cancer (MTC), or if you have MEN 2.
Source: FDA label (DailyMed).
Who should not take tirzepatide?
- Your personal or family history includes medullary thyroid cancer (MTC), or you have MEN 2.
- You experienced a serious allergic reaction to tirzepatide or one of the product's ingredients in the past.
Source: FDA label (DailyMed).
Source: FDA label (DailyMed).
Rates of serious side effects
These rates come from label trials and are shown with placebo results from the same trials.
| Problem | Label | On the drug | On placebo | More |
|---|---|---|---|---|
| Vomiting |  Mounjaro | 9% (15 mg) | 2% | Not listed |
Sources: Mounjaro label (DailyMed), Zepbound label (DailyMed).
More warnings from the Mounjaro label
- Thyroid C-cell tumors. It caused thyroid C-cell tumors in rodents; whether it causes them in people is not known. Do not take it if medullary thyroid cancer (MTC) appears in your personal or family history, or if you have MEN 2.
- Pancreatitis. Inflammation of the pancreas can occur from the drug. If stomach pain is severe and will not ease, stop taking it and get care. Sometimes the pain spreads to your back.
- Low blood sugar. Using insulin or a sulfonylurea with it increases the chance of low blood sugar; those doses may need to be lowered.
- Serious allergic reactions. Allergic reactions that are serious Reports describe serious allergic reactions that involve swelling in the face, lips or throat. When this happens, stop taking it and seek help right away.
- Kidney injury from fluid loss. Fluid loss from vomiting or diarrhea can result in kidney injury. Drink fluids and report any heavy fluid loss.
- Severe stomach and gut reactions. Severe stomach and gut reactions Side effects in these organs are common and may be severe. This medicine is not recommended if you have severe gastroparesis.
- Worsening of diabetic eye disease. With type 2 diabetes, diabetic eye disease may worsen, especially if blood sugar falls quickly. If you already have it, eye checks are important.
- Gallbladder disease. Gallstones and inflammation of the gallbladder can occur. Report yellow skin or eyes, fever, or upper right belly pain.
- Food in your lungs during anesthesia or sedation. During anesthesia or sedation: risk of food in the lungs Under anesthesia or deep sedation, food can remain in the stomach longer, so this matters. Tell your care team before you have any procedure.
Source: FDA label (DailyMed).
Long-term safety data
The trials looked at hard outcomes rather than weight alone.
| Trial | What it measured | Result | Compared with | Length |
|---|---|---|---|---|
| SURPASS-CVOT | Heart attack, stroke or death from heart disease | 12.2% vs 13.1% 8% lower risk | dulaglutide 1.5 mg (Trulicity) | Not listed |
| SURMOUNT-OSA | Breathing pauses per hour of sleep (AHI) | in Tirzepatide trial 1 (no CPAP), there were 25.3 fewer breathing pauses per hour; Tirzepatide trial 2 (on CPAP) had 29.3 fewer breathing pauses per hour | Placebo | 52 weeks |
| SUMMIT | Death from heart causes or worsening heart failure | 9.9% vs 15.3% 38% lower risk | Placebo | 104 weeks (median follow-up) |
The source information comes from SUMMIT (PubMed) and SURPASS-CVOT (PubMed).
How many people quit treatment because of side effects?
| Trial | Dose group | What happened | Drug | Placebo |
|---|---|---|---|---|
| SURMOUNT-1 | Tirzepatide 5 mg weekly | Stopped for side effects | 4.3% | 2.6% |
| SURMOUNT-1 | Tirzepatide 10 mg weekly | Stopped for side effects | 7.1% | 2.6% |
| SURMOUNT-1 | Tirzepatide 15 mg weekly | Stopped for side effects | 6.2% | 2.6% |
| SUMMIT | Tirzepatide weekly | Stopped for side effects | 6.3% | 1.4% |
Sources: SURMOUNT-1 (PubMed), SUMMIT (PubMed).