Can You Take Lansoprazole with Levothyroxine?
Last reviewed: · Source: US FDA drug label database
Like all PPIs, lansoprazole can reduce levothyroxine absorption over time — separate the doses and recheck thyroid levels after starting or stopping the PPI.
Is it safe to take Lansoprazole with Levothyroxine?
Levothyroxine absorption depends partly on stomach acid, which lansoprazole suppresses. The result can be a gradual rise in TSH and a return of hypothyroid symptoms despite an unchanged levothyroxine dose. The drugs can absolutely be used together — just take levothyroxine correctly (empty stomach, 30-60 minutes before breakfast), take lansoprazole before a different meal, and have TSH rechecked about 6-8 weeks after any PPI change.
How do Lansoprazole and Levothyroxine interact?
PPI-induced hypochlorhydria impairs levothyroxine tablet dissolution and absorption. Studies show increased levothyroxine dose requirements in long-term PPI users. Liquid/soft-gel levothyroxine formulations are less pH-dependent and are an option where the interaction proves troublesome.
Data sourced from the US Food and Drug Administration (FDA) drug label database: OpenFDA levothyroxine label — gastric acidity and absorption.
Who should be careful?
Anyone with previously stable thyroid function that drifts after starting lansoprazole, pregnant women on levothyroxine, and people already needing high or fluctuating levothyroxine doses.
What if I've already taken Lansoprazole and Levothyroxine?
No urgency — this is a slow absorption effect. Optimise dose timing as above and book a TSH test 6-8 weeks after the PPI change. Report returning tiredness, weight gain, or cold intolerance.
Not sure if this combination is safe for your specific situation?
Speak to a pharmacist online — get personalised advice in minutes.
Speak to a pharmacist online →Service provided by independent online pharmacy partners.
⭐ Recommended on Amazon
Weekly Pill Organiser
Keep your medications organised with a clear 7-day pill box — reduces missed and double doses.
View on Amazon →Medication Reminder App Guide
Practical notebook for tracking your medication, doses and any side effects you notice.
View on Amazon →Medicine Storage Box
Lockable cabinet to store all your medications safely and in one place.
View on Amazon →Affiliate links below. As an Amazon Associate we earn from qualifying purchases at no extra cost to you.
Frequently Asked Questions
Can I take lansoprazole with levothyroxine?
Yes, with sensible timing — levothyroxine on an empty stomach before breakfast, lansoprazole before another meal — and a TSH recheck after starting the PPI.
How far apart should the doses be?
Levothyroxine 30-60 minutes before breakfast; lansoprazole works well 30 minutes before the evening meal. Total separation isn't the issue — consistent routine and monitoring are.
My thyroid symptoms came back after starting lansoprazole — why?
Reduced stomach acid can lower levothyroxine absorption. A TSH test will confirm; your GP can raise the dose or switch formulation.
Do antacids cause the same problem?
Calcium/magnesium/aluminium antacids directly bind levothyroxine — separate those by at least 4 hours. The PPI effect is slower and via acid suppression.