What the FDA labels say about taking them together
Levothyroxine and sertraline
Levothyroxine's FDA label of February 20, 2024 names sertraline in its drug interactions section; the sertraline labels PlainMeds reads (3) do not name levothyroxine. The levothyroxine label: “Administration of sertraline in patients stabilized on LEVOXYL may result in increased LEVOXYL requirements.”
Check it at the source: the levothyroxine FDA label on DailyMed (effective February 20, 2024, AbbVie Inc.); the sertraline FDA label on DailyMed (effective August 8, 2023, Viatris Specialty LLC).
What does the levothyroxine label say about sertraline?
Levothyroxine label, drug interactionsAdministration of sertraline in patients stabilized on SYNTHROID may result in increased SYNTHROID requirements.
Levothyroxine Sodium label (Amneal Pharmaceuticals NY LLC, December 6, 2024), drug interactionsDrug or Drug Class: Antidepressants - Tricyclics (e.g., Amitriptyline) - Tetracyclics (e.g., Maprotiline) - Selective Serotonin Reuptake Inhibitors (SSRIs; e.g., Sertraline); Effect: Concurrent use of tri/tetracyclic antidepressants and levothyroxine may increase the therapeutic and toxic effects of both drugs, possibly due to increased receptor sensitivity to catecholamines.Toxic effects may include increased risk of cardiac arrhythmias and CNS stimulation; onset of action of tricyclics may be accelerated. Administration of sertraline in patients stabilized on levothyroxine may result in increased levothyroxine requirements.
Source: FDA drug label (Levothyroxine Sodium, NDA021210), Amneal Pharmaceuticals NY LLC, effective December 6, 2024 (SPL set fca88c97-5cd4-4834-ba87-deb5bd637788), via openFDA
Source: FDA drug label (Levothyroxine Sodium, NDA021116), Bryant Ranch Prepack, effective July 29, 2025 (SPL set 9e3bffb9-f66e-4c73-befc-e60d769f6610), via openFDA
Source: FDA drug label (Levoxyl, NDA021301), Pfizer Laboratories Div Pfizer Inc, effective December 15, 2020 (SPL set 758588c3-c63e-491b-0aa2-4f50d80cb174), via openFDA
Source: FDA drug label (Synthroid), AbbVie Inc., effective February 20, 2024 (SPL set 1e11ad30-1041-4520-10b0-8f9d30d30fcc), via openFDA; the full label on DailyMed
What does the sertraline label say about levothyroxine?
Sertraline's label (effective August 8, 2023) and its 2 other brand-application labels do not name levothyroxine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Zoloft), Viatris Specialty LLC, effective August 8, 2023 (SPL set fda754f6-d0f3-4dce-a17a-927d64f912f7), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Levothyroxine | Sertraline | |
|---|---|---|
| Labeled for | Hypothyroidism | Depression, Anxiety |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.0588 per tablet 112 mcg tablet | $0.0507 per tablet 100 mg tablet |
| Shortage now | No current entry | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once