Crestor vs Synthroid: side-by-side comparison
Crestor (Cardiovascular Medications) and Synthroid (Hormones and Birth Control) belong to different therapeutic classes and are rarely interchangeable. This page compares the medications' purposes, mechanisms and the situations where each is used.
| Property | Crestor | Synthroid |
|---|---|---|
| Active ingredient | Rosuvastatin | Levothyroxine |
| Manufacturer | AstraZeneca | AbbVie |
| Class | Cardiovascular Medications | Hormones and Birth Control |
| Strengths | 5mg, 10mg, 20mg, 40mg | 25mcg, 50mcg, 75mcg, 100mcg, 150mcg |
| Forms | tablet | tablet |
What's the same
Crestor and Synthroid are used in very different patients, and the points in common are limited. The main shared element is that both meet regulatory standards for efficacy and safety and benefit from pharmacist oversight.
Key differences
Crestor belongs to Cardiovascular Medications while Synthroid belongs to Hormones and Birth Control. Indications, mechanisms and target populations differ. The comparison is most useful when a clinician has mentioned both medications and the patient wants to understand where each fits.
Mechanism and action
Crestor: Rosuvastatin competitively inhibits HMG-CoA reductase, the rate-limiting enzyme in hepatic cholesterol synthesis. Synthroid: Levothyroxine replaces deficient endogenous thyroxine, which is converted in tissues to the active hormone triiodothyronine (T3) by deiodinase enzymes.
When Crestor is preferred
Crestor is approved in adults for the treatment of primary hypercholesterolaemia and mixed dyslipidaemia, for the prevention of cardiovascular events in patients at elevated risk and for the secondary prevention of cardiovascular events.
When Synthroid is preferred
Synthroid is approved for hypothyroidism of any cause (Hashimoto thyroiditis, post-thyroidectomy, post-radioiodine, congenital), goitre and TSH suppression after differentiated thyroid cancer.
Frequently asked questions
Is Crestor or Synthroid better? ▾
Crestor and Synthroid are not interchangeable — they treat different conditions. Asking which is "better" is meaningful only when a clinician has weighed both for the same specific clinical scenario.
Can I switch from Crestor to Synthroid? ▾
Switching between Crestor and Synthroid is rarely an appropriate decision since they belong to different classes and treat different conditions. The real question is usually whether the diagnosis calls for one medication or the other — which the prescriber resolves.
Do Crestor and Synthroid have the same side effects? ▾
No — they belong to different classes and have distinct side-effect profiles. Each medication has its own prescribing information.
More Crestor comparisons
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.