What the label lists and what reports show
Simvastatin side effects
Simvastatin's FDA label: “Most common adverse reactions (incidence ≥5%) are upper respiratory infection, headache, abdominal pain, constipation, and nausea.” FAERS holds 248,728 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is fatigue (13,810 reports).
- Generic listed
Check it at the source: the simvastatin FDA label on DailyMed (effective March 28, 2025, Organon LLC); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of ZOCOR?ZOCOR may cause serious side effects including: Muscle pain, tenderness, and weakness (myopathy). Muscle problems, including muscle breakdown, can be serious in some people and rarely cause kidney damage that can lead to death. Tell your healthcare provider right away if: you have unexplained muscle pain, tenderness, or weakness, especially if you have a fever or feel more tired than usual, while you take ZOCOR. you have muscle problems that do not go away even after your healthcare provider has advised you to stop taking ZOCOR. Your healthcare provider may do further tests to diagnose the cause of your muscle problems. […]
Source: FDA drug label, Organon LLC, effective March 28, 2025 (SPL set 8f55d5de-5a4f-4a39-8c84-c53976dd6af9), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions (incidence ≥5%) are upper respiratory infection, headache, abdominal pain, constipation, and nausea.
Table 1: Adverse Reactions Reported ≥2% of Patients Treated with ZOCOR and Greater than Placebo in Study 4S
| Reaction | % Placebo (N = 2,223) | % ZOCOR (N = 2,221) |
|---|---|---|
| Bronchitis | 6.3 | 6.6 |
| Abdominal pain | 5.8 | 5.9 |
| Atrial fibrillation | 5.1 | 5.7 |
| Gastritis | 3.9 | 4.9 |
| Eczema | 3.0 | 4.5 |
| Vertigo | 4.2 | 4.5 |
| Diabetes mellitus | 3.6 | 4.2 |
| Insomnia | 3.8 | 4.0 |
| Myalgia | 3.2 | 3.7 |
| Urinary tract infection | 3.1 | 3.2 |
| Edema/swelling | 2.3 | 2.7 |
| Headache | 2.1 | 2.5 |
| Sinusitis | 1.8 | 2.3 |
| Constipation | 1.6 | 2.2 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following important adverse reactions are described below and elsewhere in the labeling: Myopathy and Rhabdomyolysis [see Warnings and Precautions (5.1) ] Immune-Mediated Necrotizing Myopathy [see Warnings and Precautions (5.2) ] Hepatic Dysfunction [see Warnings and Precautions (5.3) ] Increases in HbA1c and Fasting Serum Glucose Levels [see Warnings and Precautions (5.4) ] Most common adverse reactions (incidence ≥5%) are upper respiratory infection, headache, abdominal pain, constipation, and nausea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Organon LLC, a subsidiary of Organon & Co., at 1-844-674-3200 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. In clinical studies, 2,423 adult patients were exposed to ZOCOR with a median duration of follow-up of approximately 18 months. The most commonly reported adverse reactions (incidence ≥5%) in these ZOCOR clinical studies were: upper respiratory infections (9%), headache (7%), abdominal pain (7%), constipation (7%), and nausea (5%). Overall, 1.4% of patients discontinued ZOCOR due to adverse reactions. …
Source: FDA drug label, Organon LLC, effective March 28, 2025 (SPL set 8f55d5de-5a4f-4a39-8c84-c53976dd6af9), via openFDA; the full label on DailyMed
What do FAERS reports show?
248,728 reports list simvastatin among the medicines taken, each a report of something that happened, not proof the medicine caused it; 22,213 are coded as a death and 95,730 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 21 reactions below, 12 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Simvastatin: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions