Lunesta vs Synthroid: side-by-side comparison
Lunesta (Sleep Aids and Hypnotics) 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 | Lunesta | Synthroid |
|---|---|---|
| Active ingredient | Eszopiclone | Levothyroxine |
| Manufacturer | Sunovion | AbbVie |
| Class | Sleep Aids and Hypnotics | Hormones and Birth Control |
| Strengths | 1mg, 2mg, 3mg | 25mcg, 50mcg, 75mcg, 100mcg, 150mcg |
| Forms | tablet | tablet |
What's the same
Lunesta 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
Lunesta belongs to Sleep Aids and Hypnotics 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
Lunesta: Eszopiclone is a positive allosteric modulator of the GABA-A receptor at a site close to the benzodiazepine binding site. Synthroid: Levothyroxine replaces deficient endogenous thyroxine, which is converted in tissues to the active hormone triiodothyronine (T3) by deiodinase enzymes.
When Lunesta is preferred
Lunesta is approved in adults for the treatment of insomnia, including difficulty falling asleep and difficulty maintaining sleep.
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 Lunesta or Synthroid better? ▾
Lunesta 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 Lunesta to Synthroid? ▾
Switching between Lunesta 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 Lunesta 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 Lunesta comparisons
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.