Drug & supplement interaction

Thyroid Extract + Salmeterol

Salmeterol brand name: Serevent.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Thyroid Extract and Salmeterol 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 label for Salmeterol states a food rule worth keeping to, and 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 Salmeterol

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 Salmeterol 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 Salmeterol and Thyroid Extract? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Salmeterol

Interactions in our licensed database are recorded against drug classes, not just single drug names. Salmeterol is filed under 3 classifications — beta-adrenergic agonists, qt interval-prolonging drugs, cytochrome p450 3a4 (cyp3a4) substrates. Thyroid Extract has documented interactions with 2 drug classes — the most serious being levothyroxine (synthroid, others) (moderate) and oral drugs (minor) — and none of Salmeterol’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 — Salmeterol 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. Salmeterol)
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 Salmeterol 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.

  • A stuffy or runny nose Additional detail

    Thyroid Extract

    “A 30-year-old female with allergic rhinitis and multinodular goiter developed allergic urticaria after treatment with desiccated thyroid extract.”

    Thyroid Extract · Natural Medicines adverse-effect record, reported in allergic rhinitis (hay fever).

    1 source cited
    1. 28619. 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

    “In one case report, a teenage female taking thyroid extract developed multiple nevi on the skin. In another case report, a 30-year-old female with allergic rhinitis and multinodular goiter developed allergic urticaria after treatment with desiccated thyroid extract.”

    Thyroid Extract · Natural Medicines adverse-effect record, reported in allergic rhinitis (hay fever).

    2 sources cited
    1. 28622. Tofahrn, J. and Hundeiker, M. [Nevus eruption following thyroidin with spontaneous involution]. Z Hautkr 1976;51(15):617-620.
    2. 28619. 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

    Salmeterol

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

  • Muscle pain 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

    Salmeterol

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

Reported for Thyroid Extract but not commonly for Salmeterol: raised blood pressure, a fast or pounding heartbeat, anxiety or restlessness and hives.

Effects for Salmeterol come from the ADVERSE REACTIONS section of its FDA label; effects for Thyroid Extract come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 107,431 voluntary FDA FAERS reports for Salmeterol that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

How to take them

Some Salmeterol Products Have a Food Rule — Thyroid Extract Should Not Break It

At least one FDA label for a product containing Salmeterol says to take it on an empty stomach. Most supplements — Thyroid Extract included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Salmeterol on its own and move Thyroid Extract to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Salmeterol products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

One inhalation of SEREVENT DISKUS at least 30 minutes before exercise has been shown to protect patients against EIB.

From the Dosage and Administration section of the FDA label we read for Salmeterol — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Salmeterol

This page covers Thyroid Extract only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Salmeterol page lists 141 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: American Hellebore (major), Arsenic (major), Cesium (major), Ephedra (major) and Grapefruit (major).

By severity: 7 major · 105 moderate · 29 minor.

From our pharmacist’s overview on the Salmeterol page

“Salmeterol (Serevent) is the long-acting inhaler taken twice daily for asthma or COPD, and its supplement list is one I would approach with real caution. Seven of the 141 ingredients on file rate major: grapefruit can raise salmeterol levels by blocking the enzyme that clears it, St.”

Reviewed by 2 · Jul 18, 2026

Open the Salmeterol interaction page

How much people look this up

Where Thyroid Extract and Salmeterol 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

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

29 days ago today
Medication Salmeterol
Steady interest

#2,546 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 September 20, 2026. The Thyroid Extract and Salmeterol 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 Salmeterol Oral Inhalation

What Is Salmeterol Oral Inhalation Used For?

Brand name: Serevent

Serevent Diskus (salmeterol inhalation powder) is used for three main purposes: treating asthma in patients aged 4 and older alongside an inhaled corticosteroid (ICS), preventing exercise-induced bronchospasm (EIB) in patients aged 4 and older, and providing long-term maintenance treatment of bronchospasm associated with COPD — including chronic bronchitis and emphysema — in adults.

Important: Serevent Diskus is not a rescue inhaler. It will not relieve a sudden asthma or COPD attack. For asthma, it must always be used together with an inhaled corticosteroid — using it alone for asthma is contraindicated due to a serious risk of asthma-related death.

See full Salmeterol Oral Inhalation 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 Salmeterol, 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 Salmeterol Together: Common Questions

Is it safe to take Thyroid Extract with Salmeterol?
We do not list a known interaction between Thyroid Extract and Salmeterol. 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 Salmeterol have any of the same side effects?
Yes — our sources link each of them separately to 2 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.
Should I take Thyroid Extract and Salmeterol at the same time of day?
At least one FDA label for a product containing Salmeterol says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Salmeterol on its own and move Thyroid Extract to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
How was the Thyroid Extract and Salmeterol combination checked?
Interactions in our licensed database are recorded against drug classes. Salmeterol is filed under 3 classifications, and Thyroid Extract has documented interactions with 2 drug classes — none of Salmeterol'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 — Salmeterol 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 Salmeterol interact with any supplements?
Yes. Salmeterol has documented interactions with 141 supplements in our database — Thyroid Extract is not one of them. The Salmeterol 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 Salmeterol Oral Inhalation drug information The full plain-English guide to this medication Salmeterol supplement interactions Every supplement checked against Salmeterol, 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 Salmeterol 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.