Statin genetic test: what SLCO1B1 can tell you, and what it can’t

Statins are cholesterol-lowering medicines. A statin genetic test is a pharmacogenomic (PGx) test, a kind of DNA test for medications, that reads a gene called SLCO1B1. It doesn’t tell you whether you need a statin. It describes how your body is likely to handle some of them, for the person who prescribes for you.

SLCO1B1 makes a transporter, a protein that carries statins from the blood into the liver, where they do their work. Some common variants make the transporter work less well, so more of certain statins stays in the blood. That is linked to a higher chance of statin-related muscle symptoms, such as aches or weakness.^[1]

CPIC’s 2022 statin guideline gives prescribers recommendations based on SLCO1B1 for several statins.^[1] These three are in our Medication Check, each at CPIC level A:^[2]

• Atorvastatin. Its guidance uses SLCO1B1.
• Simvastatin. Its guidance uses SLCO1B1.
• Rosuvastatin. Its guidance uses SLCO1B1. Its guidance also uses ABCG2, which our test does not check.

Pharmacogenomic results describe how your body is likely to process certain medicines. They do not tell you whether a medicine will work for you, and they are not dosing instructions. Never start, stop or change a medication because of a genetic result. Bring it to the prescriber who manages your medicines.

A SLCO1B1 result describes how well your transporter is likely to work, in CPIC’s terms: for example normal, decreased or poor function.^[1] With decreased or poor function, more of some statins stays in your blood, and the guideline sets out how a prescriber can take that into account.

A decreased-function result doesn’t mean you will get muscle symptoms, and a normal result doesn’t mean you won’t. Other things play a part too, including your other medicines and your health.

• Whether you need a statin. That rests on things a genetic test doesn’t read, and it is a decision for you and your clinician.
• Your health risks. It reads how you’re likely to handle some medicines, not your chance of any illness.
• Whether a statin will help you. It describes how your body is likely to handle one, not how well it will work.
• Whether you’ll have side effects. It shows one known influence on muscle symptoms, not what will happen to you.

Bring the report to whoever prescribes your statin, or to the clinician who has suggested one. Some questions to start with:

• Does my SLCO1B1 result matter for the statin I take, or one you are thinking about?
• Is there anything in my result you would want to keep an eye on?
• Which muscle symptoms should I tell you about?

GenePGx, our pharmacogenomic test, uses one saliva sample you collect at home. Checks selected known variants in 15 genes, plus CYP2D6 copy number, by genotyping. SLCO1B1 is among them, and your report sets its result beside the medicines whose guidance uses it. It tests genes named in CPIC prescribing guidelines for 56 medicines (checked September 29, 2026).

GenePGx is for adults 18 and older. To look up a single medicine first, use the Medication Check.