Drug & supplement interaction

Thyroid Extract + Methylphenidate

Methylphenidate brand names: Ritalin, Ritalin-SR, Concerta, Methylin, Metadate, and others.

Minor Interaction
Medically reviewed by · Updated November 2023
The bottom line Minor

Thyroid Extract has a minor interaction with Methylphenidate. Food and medications can interfere with thyroid hormone absorption.

Read the full interaction report
SeverityMinor
LikelihoodLikely
EvidenceA
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Thyroid Extract and Methylphenidate

Here is the interaction we found between these two, with the evidence behind it.

Minor

Oral Drugs

Why this applies to Methylphenidate

Methylphenidate falls under Oral Drugs — the group Thyroid Extract interacts with.

Food and medications can interfere with thyroid hormone absorption. Some foods, particularly those high in fiber or containing certain minerals like calcium or iron, can bind to thyroid hormones and reduce their absorption in the digestive tract. Additionally, taking thyroid medications with certain drugs, like antacids or calcium supplements, can hinder the effectiveness of the thyroid medication, necessitating adjustments in dosage or timing. Prescription thyroid medications, such as Synthroid, are recommended to be taken on an empty stomach, at least 30 minutes before food and other medications, for optimal absorption.
Severity Minor Likelihood Likely Evidence A

Well-controlled human studies have demonstrated the likely existence of this interaction.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here the concern runs in one direction: your methylphenidate (Ritalin, Concerta) can interfere with how well the body absorbs the thyroid hormone in the extract. When you swallow them close together, the stimulant pill and food in your stomach can blunt how much thyroid hormone actually gets absorbed, so the thyroid product may not work as reliably.

The good news is this is rated a minor, easily managed issue. The classic fix is timing: thyroid hormone is best taken on an empty stomach, at least 30 to 60 minutes before other medicines like your methylphenidate. Since over-the-counter thyroid extract is unpredictable to begin with, I'd really encourage you to talk with your doctor or pharmacist about whether you need it at all and how to space your doses.

Contact Dr. Brian directly if you have additional questions on this interaction

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Thyroid Extract Also Interacts With Other Medications

Thyroid Extract has 3 moderate, 2,018 minor known drug interactions in our database — the Methylphenidate one above is one of them. If you take anything else, check it against the full list below.

Moderate 3 Minor 2,018 No known interaction 809 (incl. Methylphenidate)
Taking anything else?

Check Another of Your Medications Against Thyroid Extract

Covers the 2,830 medications we’ve checked against Thyroid Extract. Pick one to open its full report.

From our Q&A

Questions About Thyroid Extract or Methylphenidate

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Thyroid Extract or Methylphenidate, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Methylphenidate

This page covers Thyroid Extract only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methylphenidate page lists 85 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Ephedra (major), Lithium (major), Peyote (major) and Rauvolfia Vomitoria (major).

By severity: 6 major · 64 moderate · 15 minor.

From our pharmacist’s overview on the Methylphenidate page

“Methylphenidate (Ritalin, Concerta, Metadate) is itself a stimulant, and that one fact shapes most of this list. The largest cluster of interacting supplements adds a second stimulant on top of it, from ephedra and its relatives to everyday caffeine sources like coffee and green tea, which can push heart rate and blood pressure higher…”

Reviewed by 2 · Jul 18, 2026

Open the Methylphenidate interaction page

How much people look this up

Where Thyroid Extract and Methylphenidate Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Thyroid Extract
Top 25%

#336 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Methylphenidate
Top 10

#5 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Thyroid Extract

What is Thyroid Extract?

Thyroid Extract
  • Hypothyroidism (underactive thyroid)
  • Fatigue and low energy
  • Weight management
  • Sluggish metabolism
  • General thyroid support

Thyroid extract supplements are made from dried animal thyroid gland and may contain real thyroid hormones (T3 and T4), but the amounts in over-the-counter products are not standardized and can be unpredictable. Self-treating a thyroid problem with these supplements can be risky, so always work with a doctor or pharmacist and use prescription thyroid medicine when treatment is needed.

Read the full Thyroid Extract monograph & all interactions
Medication

About Methylphenidate

What Is Methylphenidate Used For?

Brand names: Ritalin, Ritalin-SR, Concerta, Methylin, Metadate, Metadate CD, Methylin ER, Ritalin LA, Aptensio XR, Quillivant Xr, Cotempla XR-ODT, Jornay PM, Relexxii

Methylphenidate treats ADHD across many oral and patch products. Age ranges differ by product. Some are approved for children 6 and older, some for children and teens, and some also for adults up to age 65.

Some immediate-release and certain extended-release methylphenidate tablets are also used for narcolepsy (a sleep disorder with sudden, overwhelming sleepiness). Methylphenidate oral solution and chewable tablets are described for attention deficit disorders in children, as part of a total treatment program that includes psychological, educational and social support. Not every product is approved for every use or age group.

See full Methylphenidate drug information
Keep checking

Other Drugs & Thyroid Extract

Browse every other medication we’ve checked against Thyroid Extract — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
3Moderate
2,018Minor
808No known interaction
3 Moderate 2,018 Minor 808 No interaction
Moderate

3 interactions

Minor

2,018 interactions

Showing 60 of 2,018 minor interactions — see all 2,018 on the Thyroid Extract page.

No interaction 808 drugs checked — show the list

We also checked Thyroid Extract against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 808 medications checked with no known interaction — see the full Thyroid Extract list.

See the full Thyroid Extract interactions page
See every supplement checked against Methylphenidate, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Thyroid Extract monograph › Uses, safety, and every drug interaction in one place Methylphenidate supplement interactions › Every supplement checked against Methylphenidate, ranked by severity Methylphenidate drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Thyroid Extract and Methylphenidate Together: Common Questions

Can you take Thyroid Extract with Methylphenidate?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Thyroid Extract and Methylphenidate interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Methylphenidate and Thyroid Extract?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.