Crestor with thyroid medication (levothyroxine)
Levothyroxine is one of the most prescribed medications worldwide, and many adults on it also use chronic medications such as Crestor (Rosuvastatin). The combination is generally safe, but levothyroxine's narrow therapeutic index and finicky absorption mean a few practical points matter more than for most other co-administered drugs at 5mg, 10mg, 20mg, 40mg.
How Crestor affects thyroid medication
Levothyroxine absorption is sensitive to timing relative to food, calcium, iron and several medications. Whether Crestor interferes depends on Rosuvastatin — most agents in Cardiovascular Medications have no clinically meaningful effect on thyroid hormone levels, but a small number affect TSH or T4 free fraction. Rosuvastatin competitively inhibits HMG-CoA reductase, the rate-limiting enzyme in hepatic cholesterol synthesis.
Practical timing
According to standard endocrine practice, levothyroxine is taken on an empty stomach at least 30 minutes before food and 4 hours from interacting medications. Crestor at 5mg, 10mg, 20mg, 40mg can usually be taken at any time relative to the levothyroxine dose, but the prescribing information for Rosuvastatin should be checked for specific timing instructions.
Frequently asked questions
Will Crestor affect my thyroid levels? ▾
Most Cardiovascular Medications medications do not directly affect thyroid hormone levels at 5mg, 10mg, 20mg, 40mg. Some affect TSH testing, hormone-binding proteins or T4 free fraction in subtle ways. Routine thyroid function tests every few months catch any meaningful drift.
When should I take Crestor relative to levothyroxine? ▾
Levothyroxine is taken on an empty stomach with at least a 30-minute fast and 4-hour separation from interacting medications. Crestor at 5mg, 10mg, 20mg, 40mg usually has no specific timing constraint relative to levothyroxine; the pharmacist confirms based on the prescribing information for Rosuvastatin.
More on Crestor
- With alcoholCrestor and alcohol — is it safe to drink?
- With foodShould Crestor be taken with food?
- Side effectsCrestor side effects: common, rare and warning signs
- Dosage guideCrestor dosage guide: how much to take and when
- OnsetHow fast does Crestor start working?
- DurationHow long does Crestor last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.