Synthroid vs Elavil: side-by-side comparison
Synthroid (Hormones and Birth Control) and Elavil (Anti-Depressants) belong to different therapeutic classes and are rarely interchangeable. This page compares the medications' purposes, mechanisms and the situations where each is used.
| Property | Synthroid | Elavil |
|---|---|---|
| Active ingredient | Levothyroxine | Amitriptyline |
| Manufacturer | AbbVie | Various generics |
| Class | Hormones and Birth Control | Anti-Depressants |
| Strengths | 25mcg, 50mcg, 75mcg, 100mcg, 150mcg | 10mg, 25mg, 50mg, 75mg, 100mg |
| Forms | tablet | tablet |
What's the same
Synthroid and Elavil 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
Synthroid belongs to Hormones and Birth Control while Elavil belongs to Anti-Depressants. 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
Synthroid: Levothyroxine replaces deficient endogenous thyroxine, which is converted in tissues to the active hormone triiodothyronine (T3) by deiodinase enzymes. Elavil: Amitriptyline inhibits reuptake of serotonin and noradrenaline at central synapses.
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.
When Elavil is preferred
Amitriptyline is approved for major depressive disorder, but contemporary use is dominated by low-dose off-label indications: neuropathic pain, fibromyalgia, chronic tension headache, migraine prevention, irritable bowel syndrome, nocturnal enuresis, and insomnia.
Frequently asked questions
Is Synthroid or Elavil better? ▾
Synthroid and Elavil 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 Synthroid to Elavil? ▾
Switching between Synthroid and Elavil 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 Synthroid and Elavil 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 Synthroid comparisons
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.