Drug & supplement interaction

Thyroid Extract + Maraviroc

Maraviroc brand names: Celsentri, Selzentry.

Minor Interaction
The bottom line Minor

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

Read the full interaction report
SeverityMinor
LikelihoodLikely
EvidenceA
What do Severity, Likelihood & Evidence mean?
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Interaction report

Thyroid Extract and Maraviroc

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

Minor

Oral Drugs

Why this applies to Maraviroc

Maraviroc 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 the other way from what you might expect. It is not that Maraviroc changes your thyroid extract. Instead, taking other oral pills and food around the same time can block the thyroid hormone in the extract from being absorbed well, which is why prescription thyroid pills are usually taken on an empty stomach by themselves. If you swallow Maraviroc right alongside it, the two could compete for that absorption window.

This is rated minor, and Maraviroc itself is not a prodrug, so its HIV-fighting job should still work normally. The practical fix is simple spacing. Because thyroid extract is unstandardized and HIV therapy is too important to weaken, please let your pharmacist or doctor map out the timing for you.

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 Maraviroc one above is one of them. If you take anything else, check it against the full list below.

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.

Everything else you take

See Every Supplement That Interacts With Maraviroc

This page covers Thyroid Extract only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Maraviroc page lists 168 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 124 moderate · 38 minor.

From our pharmacist’s overview on the Maraviroc page

“Someone taking maraviroc (Selzentry) for HIV needs a steady blood level to keep the virus suppressed, and that level is exactly what most of the 168 supplements on this page can disturb, so this list calls for genuine care. About 121 entries share maraviroc's clearance route, the CYP3A4 enzyme, which means grapefruit can push levels up…”

Reviewed by 2 · Jul 18, 2026

Open the Maraviroc interaction page

How much people look this up

Where Thyroid Extract and Maraviroc 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 half

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

29 days ago today
Medication Maraviroc
Steady interest

#2,549 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 Maraviroc

What Is Maraviroc Used For?

Brand names: Celsentri, Selzentry

Maraviroc treats a specific type of HIV-1 infection called CCR5-tropic HIV-1. It is always used alongside other antiretroviral (anti-HIV) medicines — never alone. A special test called a tropism assay must be done before starting treatment to confirm you have the right type of HIV.

Selzentry (the brand-name oral solution and tablet) is approved for adults and pediatric patients weighing at least 2 kg. Generic maraviroc tablets are approved for adults and pediatric patients aged 2 years and older weighing at least 10 kg. Neither form is recommended for patients whose HIV is classified as dual/mixed-tropic or CXCR4-tropic.

See full Maraviroc 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
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.

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

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Pharmacist Counseling Corner

Taking Thyroid Extract and Maraviroc Together: Common Questions

Can you take Thyroid Extract with Maraviroc?
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 Maraviroc 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 Maraviroc and Thyroid Extract?

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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.