Based on NIH | Can atorvastatin cause diarrhea, how common is it, and what should I do if it happens?

Short answer

Yes atorvastatin can cause diarrhea. Diarrhea is listed among the common side effects in the official prescribing information and consumer medication guides. ^{[1] [2]} In pooled clinical trial data summarized in the U.S. label, diarrhea occurred in roughly 5–14% of users depending on dose and study population, making it one of the more frequently reported non‑serious adverse effects. ^[3] In many people it is mild and temporary, but if it is persistent, severe, or accompanied by concerning symptoms, you should contact your clinician to discuss dose adjustment, switching statins, or supportive care. ^{[4] [5]}

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How often does diarrhea happen with atorvastatin?

• Diarrhea is listed as a common side effect in clinical studies and consumer information for atorvastatin. ^{[1] [4]}
• In tabulated trial data from the FDA‑recognized label, diarrhea rates ranged approximately from 5% up to about 14% across different trial arms and doses. ^[3]
• Consumer medication guides also highlight diarrhea as a frequently reported effect along with upset stomach and muscle or joint pain. ^{[6] [2]}

Quick data snapshot

The figures below come from pooled trial tables in the official atorvastatin labeling; ranges reflect different doses and study cohorts reported in those tables. ^{[3] [7]}

Outcome	Reported frequency range
Diarrhea	~5% to ~14% in clinical studies
Dyspepsia (upset stomach)	~3% to ~6%
Nausea	~3% to ~7%

These ranges help illustrate that gastrointestinal effects, including diarrhea, were among the more common non‑serious adverse events captured in trials. ^[3]

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Why does it happen?

Gastrointestinal side effects with statins are thought to relate to local gut effects and individual sensitivity; they are usually mild and may improve over time as the body adjusts. ^[2] Large randomized trials evaluating overall tolerability show digestive system complaints are among the most common categories of reported events, though most are not serious. ^[8]

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What to do if you develop diarrhea

• Monitor severity and duration: Many cases are mild and settle within days to a couple of weeks. ^[2]
• Hydration and diet: Consider small sips of fluids and bland foods; avoid triggers like caffeine and high‑fat meals until symptoms ease. This general approach often helps with medication‑related loose stools.
• When to call your clinician: If diarrhea is persistent, worsens, leads to dehydration, or is accompanied by fever, blood, severe cramps, or weight loss, you should seek medical advice. ^{[2] [4]}
• Don’t stop on your own without a plan: Because atorvastatin lowers cardiovascular risk, any change should be coordinated with your clinician. ^[5]

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Options your clinician may consider

• Dose adjustment: Reducing the dose may improve tolerability while still providing cardiovascular benefit. ^[5]
• Switch to another statin: Some people tolerate a different statin better; trying an alternative agent is a common strategy. ^{[5] [9]}
• Intermittent dosing: For selected individuals, non‑daily dosing may be used to balance benefit and side effects. ^[5]
• Add or substitute non‑statin therapy: If intolerance persists, non‑statin lipid‑lowering agents may be added or substituted, understanding their own pros and cons. ^[5]

These are recognized, stepwise approaches used to manage statin side effects while aiming to keep you protected from heart attack and stroke. ^{[5] [9]}

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Red flags needing prompt attention

Seek care urgently if diarrhea is severe or accompanied by signs of dehydration (dizziness, very dry mouth, reduced urination), high fever, blood or black stools, or significant abdominal pain. ^[2] While rare, any new severe symptoms should be evaluated to rule out other causes and to ensure safe continuation or modification of therapy. ^[2]

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Key takeaways

• Diarrhea is a known and relatively common side effect of atorvastatin in clinical studies and consumer information. ^{[1] [2]}
• Reported rates in trial summaries range roughly from 5% to 14%, depending on dose and study. ^[3]
• Most cases are mild; if symptoms persist or are troublesome, contact your clinician to discuss adjustments, switching statins, or supportive care strategies, rather than stopping on your own. ^{[4] [5]}