Drug & supplement interaction

Thyroid Extract + Testosterone

Testosterone brand names: Intrinsa, Testim, Androgel, Andropatch, Testogel, and others.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Oct 4, 2026
The bottom line No known interaction

We found no known interaction between Thyroid Extract and Testosterone in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Thyroid Extract and Testosterone

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Testosterone and Thyroid Extract in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Thyroid Extract safety at a glance

Thyroid Extract overall Use caution OTC thyroid extracts may contain active hormones in unknown amounts and should not be used without medical supervision.
Pregnancy Avoid Thyroid hormone levels must be carefully controlled in pregnancy, so do not use unregulated extracts.
Breastfeeding Avoid Unregulated thyroid hormone exposure could affect the nursing infant, so avoid unless directed by a doctor.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Testosterone and Thyroid Extract? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Testosterone

Interactions in our licensed database are recorded against drug classes, not just single drug names. Testosterone is filed under 5 classifications — including androgens, topical drugs, hepatotoxic drugs. Thyroid Extract has documented interactions with 2 drug classes — the most serious being levothyroxine (synthroid, others) (moderate) and oral drugs (minor) — and none of Testosterone’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Thyroid Extract Does Interact With Other Medications

Thyroid Extract has 3 moderate, 2,019 minor known drug interactions in our database — Testosterone isn’t one of them. If you take anything else, check it against the full list below.

Moderate 3 Minor 2,019 No known interaction 808 (incl. Testosterone)
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.

What to actually watch for

No Interaction Found — But Data Suggests Thyroid Extract and Testosterone May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • Raised blood pressure Worth acting on Additional detail

    Thyroid Extract

    “Clinical research shows that many patients treated with thyroid extract experience abnormally high levels of triiodothyronine (T3) and/or thyroxine (T4). In some patients, these elevated hormone levels result in thyrotoxic crisis or thyroid storm, with symptoms including nausea, vomiting, myalgia, fever, tachycardia, hypertension, agitation, and altered mental state.”

    Thyroid Extract · Natural Medicines adverse-effect record, reported in hypertension.

    3 sources cited
    1. 28621. Gerard, P., Malvaux, P., and De Visscher, M. Accidental poisoning with thyroid extract treated by exchange transfusion. Arch Dis Child 1972;47(256):981-982. PubMed
    2. 29987. Jackson IM, Cobb WE. Why does anyone still use desiccated thyroid USP? Am J Med 1978;64(2):284-8. PubMed
    3. 97621. Jha S, Waghdhare S, Reddi R, Bhattacharya P. Thyroid storm due to inappropriate administration of a compounded thyroid hormone preparation successfully treated with plasmapheresis. Thyroid. 2012;22(12):1283-6. PubMed

    Testosterone

    Listed in the ADVERSE REACTIONS section of the FDA label for Testosterone. Read the label on DailyMed ›

  • Anxiety or restlessness / Nausea Additional detail

    Thyroid Extract

    Recorded for Thyroid Extract in the same Natural Medicines adverse-effect record shown under Raised blood pressure above.

    Testosterone

    Listed in the ADVERSE REACTIONS section of the FDA label for Testosterone. Read the label on DailyMed ›

Reported for Thyroid Extract but not commonly for Testosterone: a fast or pounding heartbeat, hives, vomiting and a stuffy or runny nose.

Effects for Testosterone come from the ADVERSE REACTIONS section of its FDA label; effects for Thyroid Extract come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

From our Q&A

Questions About Thyroid Extract or Testosterone

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 Testosterone, 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 Testosterone

This page covers Thyroid Extract only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Testosterone page lists 170 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 5 major · 129 moderate · 36 minor.

From our pharmacist’s overview on the Testosterone page

“The supplement list for testosterone therapy (Androgel, Testim, Nebido, and others) deserves real attention, mainly because five of its 170 entries are rated major and four of those are everyday items: grapefruit, St. John's wort, and alcohol in the form of beer or wine.”

Reviewed by 2 · Jul 18, 2026

Open the Testosterone interaction page

How much people look this up

Where Thyroid Extract and Testosterone 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 Testosterone
Top 1%

#13 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Thyroid Extract reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified October 4, 2026. The Thyroid Extract and Testosterone records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
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.

Animal thyroid gland tissue (commonly from pigs or cows) · Capsules, tablets, dried powder

An interaction check asks whether these two react with each other — it does not ask whether Thyroid Extract is a good idea for someone in your situation. Here is what our Thyroid Extract record says about it on its own.

Thyroid Extract: dosing

There is no established or standardized safe dose for over-the-counter thyroid extract supplements, partly because their hormone content varies from product to product. This is a major reason healthcare providers are cautious about them.If thyroid hormone replacement is truly needed, it should be prescribed and monitored by a doctor, often with regular blood tests to fine-tune the dose. Never adjust or stop prescription thyroid medicine on your own.

From our Thyroid Extract monograph — the full record covers uses, side effects and every documented interaction.

Read the full Thyroid Extract monograph & all interactions
Medication

About Testosterone

What Is Testosterone Used For?

Brand names: Intrinsa, Testim, Androgel, Andropatch, Testogel, Nebido, Delatestryl, Natesto, Vogelxo

Testosterone products are used as replacement therapy in men with low or absent natural testosterone. This is called hypogonadism (the body doesn't make enough testosterone).

Labels list two types: primary hypogonadism (a problem in the testicles) and hypogonadotropic hypogonadism (a problem with the brain's pituitary or hypothalamus signals). Some labels, such as Testopel pellets, also mention helping start puberty in carefully selected males with clearly delayed puberty.

See full Testosterone 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
2,019Minor
807No known interaction
3 Moderate 2,019 Minor 807 No interaction
Moderate

3 interactions

Minor

2,019 interactions

Showing 60 of 2,019 minor interactions — see all 2,019 on the Thyroid Extract page.

No interaction 807 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 807 medications checked with no known interaction — see the full Thyroid Extract list.

See the full Thyroid Extract interactions page
See every supplement checked against Testosterone, ranked by severity
Evidence & sources

Thyroid Extract References

The 6 references that drive our Thyroid Extract monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Benvenga, S., Trimarchi, F., Barbera, C., Costante, G., Morabito, S., Barberio, G., and Consolo, F. Circulating immunoglobulin E (IgE) antibodies to L-thyroxine in a euthyroid patient with multinodular goiter and allergic rhinitis. J Endocrinol Invest 198 PubMed
  2. Gerard, P., Malvaux, P., and De Visscher, M. Accidental poisoning with thyroid extract treated by exchange transfusion. Arch Dis Child 1972;47(256):981-982. PubMed
  3. Tofahrn, J. and Hundeiker, M. [Nevus eruption following thyroidin with spontaneous involution]. Z Hautkr 1976;51(15):617-620.
  4. Rees-Jones RW, Larsen PR. Triiodothyronine and thyroxine content of desiccated thyroid tablets. Metabolism 1977;26(11):1213-1218. PubMed
  5. Jackson IM, Cobb WE. Why does anyone still use desiccated thyroid USP? Am J Med 1978;64(2):284-8. PubMed
  6. Jha S, Waghdhare S, Reddi R, Bhattacharya P. Thyroid storm due to inappropriate administration of a compounded thyroid hormone preparation successfully treated with plasmapheresis. Thyroid. 2012;22(12):1283-6. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Thyroid Extract and Testosterone Together: Common Questions

Is it safe to take Thyroid Extract with Testosterone?
We do not list a known interaction between Thyroid Extract and Testosterone. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Thyroid Extract and Testosterone have any of the same side effects?
Yes — our sources link each of them separately to 3 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Thyroid Extract and Testosterone combination checked?
Interactions in our licensed database are recorded against drug classes. Testosterone is filed under 5 classifications, and Thyroid Extract has documented interactions with 2 drug classes — none of Testosterone's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Thyroid Extract interact with any other medications?
Yes. Thyroid Extract has 2,022 documented drug interactions in our database — Testosterone is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Testosterone interact with any supplements?
Yes. Testosterone has documented interactions with 170 supplements in our database — Thyroid Extract is not one of them. The Testosterone interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Thyroid Extract monograph Uses, safety profile, and every drug interaction in one place Testosterone drug information The full plain-English guide to this medication Testosterone supplement interactions Every supplement checked against Testosterone, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 6 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Testosterone 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.