Levothyroxine interactions
Overview
Levothyroxine (Synthroid, Levoxyl) is a thyroid hormone replacement. In our database it has 8 known interactions with common medicines and substances: 0 serious, 8 that need caution and 0 minor.
Use caution 8 interactions
Can reduce thyroid medicine absorptionEsomeprazole
Can reduce thyroid medicine absorptionFamotidine
Can reduce thyroid medicine absorptionIron supplements
Can reduce thyroid medicine absorptionMagnesium
Can reduce thyroid medicine absorptionOmeprazole
Can reduce thyroid medicine absorptionPantoprazole
Can reduce thyroid medicine absorptionZinc
Can reduce thyroid medicine absorption
No known interaction found
Our rules found no interaction between Levothyroxine and: Acetaminophen, Acyclovir, Albuterol, Alcohol, Allopurinol, Alprazolam, Amitriptyline, Amlodipine, Amoxicillin, Amoxicillin-clavulanate, Amphetamine salts, Apixaban, Aripiprazole, Ashwagandha, Aspirin, Atenolol, Atorvastatin, Azithromycin, Baclofen, Birth control pills, Bismuth subsalicylate, Buprenorphine-naloxone, Bupropion, Buspirone, Caffeine, Cannabis, Carvedilol, Celecoxib, Cephalexin, Cetirizine, Ciprofloxacin, Citalopram, Clindamycin, Clonazepam, Clonidine, Clopidogrel, Codeine, Colchicine, Creatine, Cyclobenzaprine, DayQuil, Dextromethorphan, Diazepam, Diclofenac, Digoxin, Diphenhydramine, Doxycycline, Doxylamine, Duloxetine, Empagliflozin, Escitalopram, Estradiol, Excedrin, Fexofenadine, Finasteride, Fish oil, Fluconazole, Fluoxetine, Furosemide, Gabapentin, Glipizide, Grapefruit juice, Guaifenesin, Hydrochlorothiazide, Hydrocodone, Hydroxychloroquine, Hydroxyzine, Ibuprofen, Insulin, Isotretinoin, Kratom, Lamotrigine, Levetiracetam, Levofloxacin, Lisdexamfetamine, Lisinopril, Lithium, Loperamide, Loratadine, Lorazepam, Losartan, Meclizine, Melatonin, Meloxicam, Metformin, Methocarbamol, Methotrexate, Methylphenidate, Methylprednisolone, Metoprolol, Metronidazole, Mirtazapine, Montelukast, Morphine, Naltrexone, Naproxen, Nicotine, Nitrofurantoin, NyQuil, Ondansetron, Oseltamivir, Oxycodone, Paroxetine, Paxlovid, Phentermine, Phenylephrine, Potassium supplements, Pravastatin, Prednisone, Pregabalin, Probiotics, Promethazine, Propranolol, Pseudoephedrine, Quetiapine, Rivaroxaban, Rosuvastatin, Semaglutide, Sertraline, Sildenafil, Simvastatin, Spironolactone, St. John's wort, Sulfamethoxazole-trimethoprim, Sumatriptan, Tadalafil, Tamsulosin, Tirzepatide, Tizanidine, Topiramate, Tramadol, Trazodone, Turmeric, Valacyclovir, Venlafaxine, Vitamin D, Warfarin, Zolpidem.
Add at least two medicines, supplements or alcohol.
Sources
Source: FDA label for Levothyroxine on DailyMed (effective 2026-09), plus the labels of each interacting medicine.
This list covers the 147 medicines and substances in our database. It is not a complete list of every possible interaction. Always tell your doctor and pharmacist about every medicine, supplement and herbal product you take.