- 01Your own baseline is the yardstick
On a statin, the question is how far LDL fell from your own pre-statin number (30 to 49% on moderate intensity, 50% or more on high intensity), not whether the lab flags it high or low. The flag compares you with a population; the percent drop compares you with yourself.
On a lab report, a statin's effect shows up as a fall in your follow-up LDL cholesterol from your own starting number: 30 to 49% on a moderate-intensity statin, 50% or more on a high-intensity one 1. The follow-up lipid panel usually comes 4 to 12 weeks after the statin is started or the dose changes 1. LDL (low-density lipoprotein) is the main artery-clogging cholesterol on the panel, and the percent drop from your pre-statin result is the first number to read.
How statins lower LDL and ApoB
Statins block HMG-CoA reductase, the enzyme liver cells use to build cholesterol. The drop on your panel comes from how the liver responds to that block.
How a statin pulls LDL out of your blood
For a line-by-line read of the panel itself, see how to read your lipid panel. On a statin, four markers move: LDL cholesterol, non-HDL cholesterol, ApoB and, to a smaller degree, triglycerides.
Expected LDL drop by statin intensity
The 2018 AHA/ACC cholesterol guideline (from the American Heart Association and the American College of Cardiology) groups statins by how much they lower LDL from your own baseline, and labels each group by intensity 1.
| Intensity | Expected LDL drop from your baseline | Examples (the prescriber sets the dose) |
|---|---|---|
| High | 50% or more | Atorvastatin or rosuvastatin at their higher doses |
| Moderate | 30 to 49% | Lower doses of atorvastatin or rosuvastatin; standard doses of simvastatin or pravastatin |
| Low | Under 30% | Low doses of simvastatin, pravastatin, lovastatin or fluvastatin |
Work out your own percent drop
- 1Find your pre-statin LDLUse the panel drawn before the first dose. Example: 160 mg/dL.
- 2Find your follow-up LDLUse the panel drawn 4 to 12 weeks after starting or a dose change 1. Example: 90 mg/dL.
- 3Subtract, then divide by the starting value160 minus 90 is 70. 70 divided by 160 is 0.44, so LDL fell 44%.
- 4Match the drop to the intensityA 44% drop sits in the moderate-intensity band of 30 to 49%. From the same start of 160 mg/dL, a high-intensity statin would be expected to bring LDL to about 80 mg/dL or lower.
- 5Bring both numbers to the prescriberThe guideline uses this panel to check both response and whether doses are being taken 1. A drop smaller than the band can come from missed doses, lab-to-lab differences or individual response, and the prescriber works out which.
Example: a 44% LDL drop on a statin% drop from pre-statin LDL
If you have your lipid panel in hand, the calculator below reads each line of it.
The numbers your lipid panel implies
Enter three values, read LDL, non-HDL, and your ratio. Nothing leaves your browser.
Why the size of the drop matters
The benefit of a statin tracks how far LDL falls. The Cholesterol Treatment Trialists' (CTT) Collaboration pooled 26 randomised trials (a meta-analysis, which combines results across studies) with about 170,000 people. It found that each 1.0 mmol/L (about 39 mg/dL; see lab units explained if your report uses mmol/L) reduction in LDL cut major vascular events, meaning heart attacks, strokes and artery-opening procedures, by about 22% 2. That is why your own before-and-after comparison carries more information than a single reading. A single result can shift with lab-to-lab variation; trends beat single readings shows how to compare results over time.
LDL numbers the guideline uses
LDL still has absolute cutoffs. The 2018 AHA/ACC guideline uses them to decide who is offered a statin and at what intensity 1. The high cholesterol page covers the risk categories in full.
| LDL (mg/dL) | How the 2018 AHA/ACC guideline uses the number |
|---|---|
| 190 or higher | Severe high cholesterol: a high-intensity statin is recommended without a risk score, and inherited causes such as FH (familial hypercholesterolemia, high LDL that runs in families) are considered 1 |
| 160 to 189 | A risk-enhancing factor (something that pushes a borderline risk toward treatment) that can tip a borderline 10-year heart risk toward a statin; an ApoB of 130 mg/dL or higher counts the same way 1 |
| 70 to 189 | In adults 40 to 75 without diabetes or heart disease, the 10-year risk estimate (your doctor's estimate of your chance of a heart attack or stroke in the next 10 years), more than LDL alone, guides whether a statin is offered. Adults 40 to 75 with diabetes and LDL of 70 or higher are generally offered a statin without a risk score 1 |
| 70 or higher on the highest tolerated statin | In people with a prior heart attack or stroke at very high risk, the level at which adding a non-statin drug (a second cholesterol medicine added to the statin) is considered 1 |
The high and low flags on your lab report compare your LDL with a population reference range, which is a different question from whether the statin is doing its job. Our guide to reference ranges explains where those flags come from. An LDL inside the lab's normal range can still sit above the goal your prescriber has set, and a flagged LDL can still be a good result if it is half of where you started. Ask your prescriber which yardstick they are using: a percent drop, a target number, or both.
LDL, non-HDL and ApoB on a statin
Three numbers on or near the lipid panel track the same artery-clogging particles in different ways. LDL is the main scorecard for statin response; non-HDL and ApoB help when LDL reads less reliably.
| LDL cholesterol | Non-HDL cholesterol | ApoB | |
|---|---|---|---|
| What it measures | Cholesterol carried in LDL particles, often calculated rather than measured | Total cholesterol minus HDL (high-density lipoprotein, the cholesterol carried away from arteries): cholesterol in all artery-clogging particles | The number of artery-clogging particles, since each carries one ApoB |
| Fasting needed? | Usually not 1 | No | No |
| On a standard lipid panel? | Yes | Yes, or easy to work out from total cholesterol and HDL | Usually a separate order |
| When it helps most | The main yardstick for statin intensity and response 1 | When triglycerides are high and calculated LDL is less reliable | When LDL and particle count may disagree, as with high triglycerides, diabetes or obesity; 130 mg/dL or higher is a risk enhancer 1 |
If you have both an LDL and an ApoB result, the checker below shows whether they agree.
Do your apoB and LDL agree?
Enter both numbers to see whether your particle count and your cholesterol tell the same story. Nothing leaves your browser.
Fasting, cost and how often to retest
A nonfasting lipid panel works for most people. The 2018 guideline suggests a fasting repeat when nonfasting triglycerides come back at 400 mg/dL or higher 1. The standard lipid panel is a routine, low-cost blood test that is often drawn with other yearly labs; ApoB is usually ordered separately, so ask whether your insurance covers it. After the first follow-up panel at 4 to 12 weeks, the guideline describes repeating the lipid panel every 3 to 12 months as needed 1.
If your pre-statin LDL was 190 mg/dL or higher, ask your prescriber whether FH is a possibility. Because FH is inherited, the 2018 guideline supports checking cholesterol in close relatives such as parents, siblings and children 1.
An underactive thyroid is one of the secondary causes of high LDL the guideline asks clinicians to look for 1, and it also makes statin muscle symptoms more likely 6. It is reasonable to ask whether your TSH has been checked. See hypothyroidism and, if you already take thyroid medicine, levothyroxine.
Three other labs can move on a statin: ALT, CK and HbA1c. Each changes in a small, known way, and each has a point where the change needs attention.
| Lab | Typical change on a statin | When the change matters |
|---|---|---|
| ALT (alanine aminotransferase, a liver enzyme) | A mild rise in some people, often under 3 times the upper limit of normal (ULN) 6 | A rise to 3 times ULN or higher 6, or symptoms of liver injury such as yellow skin or eyes, dark urine or pain under the right ribs 1 |
| CK (creatine kinase, an enzyme released by damaged muscle) | Not checked routinely, though a baseline CK may be drawn in people at higher risk of muscle problems 1; usually unchanged | Checked when severe muscle pain or weakness appears 1; a very high CK with muscle pain needs urgent care |
| HbA1c and fasting glucose | A small upward drift in some people 4 | A move across the prediabetes or diabetes cutoff; about 1 extra diabetes case per 255 people treated for 4 years 4 |
Statins and liver enzymes (ALT)
Statin labels once called for regular liver enzyme checks. In February 2012 the FDA removed that requirement, keeping a baseline check before starting and testing when symptoms point to the liver, because routine checks did not prevent the rare cases of serious injury 5.
Serious liver injury with statins is rare and unpredictable in individual patients.US Food and Drug Administration, Drug Safety Communication on statin label changes, February 2012 5
A small rise in ALT on a statin, under 3 times the upper limit of normal, can occur 6. On its own, a rise that size is not by itself a sign of serious statin-related liver injury, but it can have several causes, so it is a number to discuss with the prescriber 6 5. AST, the other liver enzyme on a metabolic panel, can rise along with it. Fatty liver, alcohol and other medicines also raise ALT; liver enzymes explained and the fatty liver page walk through those causes.
Yellowing of the skin or eyes, dark urine, or pain under the right ribs on a statin need same-day medical care, whatever the ALT number.
Statins and blood sugar (HbA1c)
Statins raise blood sugar slightly in some people. A 2010 meta-analysis of 13 statin trials found about 9% higher odds of new diabetes than in people not on a statin, a small increase on a small starting risk. That works out to roughly 1 extra case for every 255 people treated for 4 years 4. The same analysis estimated about 5 fewer coronary events (heart attacks or deaths from heart disease) in those 255 people over the same 4 years 4. The markers to watch are HbA1c, a 3-month average of blood sugar, and fasting glucose.
Statin therapy is associated with a slightly increased risk of development of diabetes, but the risk is low both in absolute terms and when compared with the reduction in coronary events.Sattar N et al., The Lancet, 2010 4
If your HbA1c crosses the prediabetes or diabetes cutoff after starting a statin, bring the before and after values to your prescriber. Blood sugar explained shows how to read HbA1c and fasting glucose.
Are muscle aches on a statin caused by the statin?
In large trials, most muscle complaints in people on a statin were not caused by the statin. In 19 trials where neither patients nor doctors knew who got the statin and who got a dummy pill (placebo), with more than 120,000 people, 27.1% of people taking a statin and 26.6% taking a placebo reported muscle pain or weakness 3. The CTT Collaboration concluded that more than 90% of muscle complaints in people on a statin were not caused by the drug, and the small excess that was caused by the statin appeared mostly in the first year 3. Trial averages cannot tell whether your own symptoms come from the drug; that is for your prescriber to assess.
True statin myopathy (muscle damage caused by the drug) is rare. It shows up as muscle pain or weakness together with a raised CK, which is why CK is measured when symptoms appear rather than on a schedule 1. Its severe form, rhabdomyolysis (rapid muscle breakdown that can injure the kidneys), is rarer still. Doctors check the kidneys with a creatinine and eGFR blood test; kidney function explained shows how to read them. Questions about CoQ10 for statin-related aches are answered on the CoQ10 page.
For the wider set of heart-related markers, the heart topic page links each one.
Link · Circulation2018 AHA/ACC guideline on the management of blood cholesterolThe full guideline that defines statin intensity, the 4 to 12 week follow-up panel, and the LDL thresholds used in US practice.ahajournals.orgCitations
- Grundy SM et al. 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol. Circulation. 2019;139:e1082-e1143
- Cholesterol Treatment Trialists' (CTT) Collaboration. Efficacy and safety of more intensive lowering of LDL cholesterol: a meta-analysis of data from 170,000 participants in 26 randomised trials. Lancet. 2010;376:1670-1681
- Cholesterol Treatment Trialists' (CTT) Collaboration. Effect of statin therapy on muscle symptoms: an individual participant data meta-analysis of large-scale, randomised, double-blind trials. Lancet. 2022;400:832-845
- Sattar N et al. Statins and risk of incident diabetes: a collaborative meta-analysis of randomised statin trials. Lancet. 2010;375:735-742
- US FDA. Drug Safety Communication: Important safety label changes to cholesterol-lowering statin drugs (February 2012)
- Newman CB et al. Statin Safety and Associated Adverse Events: A Scientific Statement From the American Heart Association. Arterioscler Thromb Vasc Biol. 2019;39:e38-e81
Educational context only, not medical advice or a diagnosis. Always discuss your results with a clinician.