Statins do cause side effects, but fewer than most people expect. In blinded trials, where nobody knew who was taking the statin and who was taking a dummy pill, muscle aches were reported almost as often on the dummy pill.
The side effects with solid trial evidence are a small excess of muscle pain in the first year, a small upward shift in blood sugar, and changes in liver blood tests. Serious muscle or liver injury is rare. If you have symptoms, they deserve a proper look, and the right move is a conversation with your prescriber.
Key takeaways
- In pooled blinded trials, about 27% of people reported muscle pain or weakness whether they took a statin or a placebo.
- Experiments that switched people between statin, placebo and no pill suggest most symptoms come from taking a tablet, not from the drug.
- Statins raise the chance of a new diabetes diagnosis, mainly in people whose blood sugar was already near the threshold.
- Serious muscle damage and serious liver injury are both rare.
- Report symptoms to your prescriber instead of stopping the medication yourself.
Muscle symptoms: what blinded trials found
Muscle aches are common in adults whether or not they take a statin. That makes it hard to know the cause from one person's experience, and it is why blinded trials matter.
The Cholesterol Treatment Trialists' Collaboration pooled 19 placebo-controlled trials with nearly 124,000 participants. Over about four years, 27.1% of people on a statin and 26.6% of people on placebo reported muscle pain or weakness.1
The difference showed up in the first year. During that year, statins produced a 7% relative increase in muscle pain or weakness, which works out to about 11 extra reports per 1,000 people per year. The authors estimated that only about one in 15 muscle reports from people on a statin in that year was caused by the statin. After the first year, there was no significant excess.
The pain that statins did cause was mostly mild.
The nocebo evidence
A nocebo effect is a real symptom brought on by expecting harm from a treatment. It does not mean the symptom is imagined.
The SAMSON trial tested this in 60 people who had stopped statins because of side effects. Each person received twelve one-month bottles: four with a statin, four with a placebo and four empty. They scored their symptoms every day without knowing which pill was which.
Average symptom scores were 8.0 in months with no tablets, 16.3 in statin months and 15.4 in placebo months. Symptoms rose when people took any tablet, and the statin and placebo months did not differ. The researchers calculated that 90% of the symptom burden from statin tablets also appeared with placebo tablets.2
A larger UK trial, StatinWISE, used a similar design in 200 people who had stopped or were thinking of stopping a statin because of muscle symptoms. It found no overall difference in muscle symptom scores between statin and placebo periods.3
These trials have limits. They were small, each tested one statin at one strength, and they report averages. They do not rule out true statin-related muscle symptoms in an individual. They do show that the timing of a symptom, starting after a pill and easing after stopping, cannot prove the drug caused it.
Blood sugar and diabetes
Statins shift blood sugar slightly upward. In pooled blinded trials, low-intensity or moderate-intensity statin treatment produced a 10% proportional increase in new diabetes diagnoses, and high-intensity treatment a 36% proportional increase.4
Two details put that in context. The average rise in A1c was small, under a tenth of a percentage point. And most new diagnoses happened in people whose blood sugar was already close to the diabetes threshold before they started.
The authors also point out that the heart benefit measured in these trials already includes any harm from the blood sugar change. If your glucose or A1c is borderline, that is useful for your prescriber to know. Our page on insulin resistance covers that side of the picture.
Liver, memory and other concerns
| Concern | What the evidence shows |
|---|---|
| Serious muscle injury (rhabdomyolysis) | Rare: under 0.1% in an American Heart Association review |
| Serious liver injury | Very rare: about 0.001% in the same review |
| Abnormal liver blood tests | Slightly more common on a statin than on placebo in blinded trials |
| Memory problems, depression, sleep disturbance, nerve damage | Blinded trial data do not support a causal link |
The American Heart Association review put the risk of serious muscle injury below 0.1% and the risk of serious liver toxicity at about 0.001%.5
A 2026 analysis checked 66 other side effects listed on statin labels against blinded trial data and found a significant excess for only four, including abnormal liver blood tests.6 It did not find support for cognitive impairment, depression, sleep disturbance or peripheral neuropathy.
Statin side effects in women
Women were a minority in many statin trials, so it is fair to ask whether the evidence applies to them. In a pooled analysis of 27 trials with about 174,000 participants, statins lowered major vascular events by a similar proportion in women and men at the same level of risk.7
Reports of side effects are where women and men differ. A meta-analysis of 176 studies with more than 4 million patients found that female sex was linked to higher odds of statin intolerance, along with older age, obesity, diabetes and an underactive thyroid.8 Intolerance was reported far less often in randomized trials than in observational studies, 4.9% compared with 17%.8
On blood sugar, a large observational study of postmenopausal women in the Women's Health Initiative linked statin use to a 48% higher risk of a new diabetes diagnosis.9 That study was not randomized. In the blinded trials described above, the relative rise in diabetes diagnoses was similar across the different types of participants studied.4
Pregnancy is a separate question. In 2021 the FDA removed the pregnancy Category X designation from statins.10 A 2026 meta-analysis of 21 studies found no link between statin use in pregnancy and birth defects, but its authors still called for an individual risk-benefit decision rather than routine use.10 If you are pregnant, planning a pregnancy or breastfeeding, talk to your prescriber before making any change.
What to tell your prescriber
Do not quit, skip or change the strength of a statin by yourself, and do not restart one by yourself either. Bring your prescriber the details instead:
- What the symptom is, where you feel it, and whether it is on both sides.
- When it began in relation to starting or changing the medication.
- Any new exercise, injury or illness around the same time.
- Every other medication and supplement you take.
- Any history of thyroid, kidney or liver problems.
Call promptly if you have severe muscle pain, marked weakness or dark urine. These are uncommon, and they need same-day medical attention.
Your prescriber has several ways to respond, and choosing among them is their job. Our guides to non-statin medicines and CoQ10 and statins describe the evidence for two things people often ask about.
Next step: bring data to the conversation
If you are weighing a statin against its side effects, it helps to know what the statin is doing for you. ApoB, Lp(a), hs-CRP, glucose, insulin and A1c are part of the lab panel in both Cardio Res-Q assessments: the Comprehensive Assessment ($775) and the Enhanced Assessment ($999).
See the Cardio Res-Q program page for what each includes, and read Already on a Statin? before you book. The clinic can share results with your prescriber. Medication changes go through the clinician who prescribes for you.
Are You a Candidate for Cardio Res-Q?
Three quick questions about the risk factors we screen for. Your answers stay between you and the clinic.
Frequently asked questions
How common are muscle aches from statins?
Muscle aches are common, but most are not caused by the statin. In pooled blinded trials about 27% of people reported muscle pain or weakness on a statin and nearly the same share on placebo. The excess caused by statins was about 11 extra reports per 1,000 people in the first year, and none was detected after that.
Does the nocebo effect mean my symptoms are not real?
No. Nocebo symptoms are felt in the body and can be strong enough to make people stop treatment. What the trials show is that the same symptoms often appear with a placebo tablet. That is a reason to work through the cause with your prescriber, not a reason to dismiss what you feel.
Do statins cause diabetes?
They raise the chance of a new diagnosis modestly, and more with high-intensity treatment. Most of those diagnoses occur in people whose blood sugar was already near the diabetes range. Trial results on heart attacks and strokes already account for this effect.
Related reading
This article is for general education and is not medical advice. Decisions about testing and medication should be made with your clinician. If you have chest pain or other symptoms of a heart attack, call 911.
