Simvastatin — Cholesterol Lowering Guide | KiwiMeds
✅ Reviewed by a Registered Pharmacist NZ | Last updated: May 2026 | This information is for educational purposes only and does not replace advice from your doctor or pharmacist.
What is simvastatin?
Simvastatin is a statin medication used to lower LDL (“bad”) cholesterol and triglycerides while raising HDL (“good”) cholesterol. It reduces the risk of heart attacks and strokes. In New Zealand, simvastatin is available as a generic and is one of the most commonly prescribed statins alongside atorvastatin.
What is it used for? (NZ context)
Simvastatin is prescribed to reduce cardiovascular risk in people with high cholesterol, diabetes, or existing heart disease. It is fully funded by Pharmac. It is usually taken lifelong as part of a heart health strategy.
How does it work?
Simvastatin is a HMG-CoA reductase inhibitor (statin). It blocks the enzyme the liver uses to produce cholesterol. The liver then takes more cholesterol from the blood to compensate, lowering blood cholesterol levels. It also has anti-inflammatory effects on blood vessel walls.
How to take it
Simvastatin is taken once daily, typically in the evening (cholesterol production is highest at night). Avoid grapefruit and grapefruit juice — it significantly increases simvastatin levels and the risk of side effects. Take with or without food.
Common side effects
- Muscle aches or weakness (myalgia)
- Headache
- Nausea or stomach upset
- Fatigue
Serious side effects to watch for
Rarely, statins can cause rhabdomyolysis — severe muscle breakdown that can damage the kidneys. Report any unexplained severe muscle pain, weakness, or dark urine to your doctor immediately. Liver problems are rare but your doctor may monitor liver function tests.
Important drug interactions
Grapefruit juice increases simvastatin blood levels substantially — avoid entirely. Some antibiotics (clarithromycin, erythromycin), antifungals (fluconazole), amiodarone, and calcium channel blockers significantly increase simvastatin levels and the risk of muscle side effects. Amlodipine — maximum dose of simvastatin is 20mg if taken together.
NZ-specific information
Pharmac funding: Simvastatin 10mg, 20mg, and 40mg tablets are fully funded by Pharmac. The 80mg dose is not recommended due to high risk of muscle side effects. NZ brand names include Zocor (original) and many generics.
Frequently asked questions
Should I take simvastatin in the morning or evening?
Evening is preferred because the liver makes most cholesterol overnight, so simvastatin is more effective when taken at night. However, consistency matters most — take it at the same time each day.
Why can’t I have grapefruit with simvastatin?
Grapefruit contains compounds that block a liver enzyme that breaks down simvastatin. This causes simvastatin levels in the blood to rise significantly, increasing the risk of muscle damage. Even one glass can have an effect. Atorvastatin is also affected.
Do I need to stop statins if my muscles hurt?
Minor muscle aches are common and often improve. However, if you have severe, unexplained muscle pain or weakness, stop taking it and contact your doctor promptly.
💬 Talk to your pharmacist or doctor for personalised advice about simvastatin.
Reviewed by a Registered Pharmacist NZ | BPharm, Pharmacy Council of New Zealand
References & Further Information
The following New Zealand and international resources were used to inform this page: