Drug & supplement interaction

Diiodothyronine + Formoterol

Formoterol brand names: Foradil Aerolizer, Atimos Modulite, Oxis Turbohaler, Perforomist, Foradil Certihaler.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated June 2026 · Pair last verified Sep 13, 2026

The bottom line No known interaction

We found no known interaction between Diiodothyronine and Formoterol 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.

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Interaction report

Diiodothyronine and Formoterol

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 Formoterol and Diiodothyronine 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Diiodothyronine at all — not against Formoterol, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Diiodothyronine safety at a glance

Diiodothyronine overall Use caution It is a thyroid-active compound with limited human safety data and possible effects on the heart and thyroid.

Pregnancy Avoid Avoid during pregnancy; thyroid-active compounds can affect mother and baby and safety is unknown.

Breastfeeding Avoid Avoid while breastfeeding due to unknown effects on the infant.

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

Still wondering about combining Formoterol and Diiodothyronine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

What to actually watch for

What Formoterol’s Own FDA Label Lists

This is not an interaction — none of it involves Diiodothyronine. These are the most notable effects listed in the ADVERSE REACTIONS section of Formoterol’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 7 of them are worth acting on rather than waiting out — marked below.

Low potassium Worth acting on
High blood sugar Worth acting on
Wheezing Worth acting on
Chest pain Worth acting on
Raised blood pressure Worth acting on
A severe allergic reaction Worth acting on
Hives Worth acting on
Tremor or shakiness
Dry mouth
A fast or pounding heartbeat

Showing the 10 most notable of 22 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Formoterol. Read the label on DailyMed › Diiodothyronine’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Diiodothyronine side to compare — that is a limit of the record, not a statement that Diiodothyronine has no side effects.

Everything else you take

See Every Supplement That Interacts With Formoterol

This page covers Diiodothyronine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Formoterol page lists 103 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,3-dmaa (moderate), Acacia Rigidula (moderate), Active Hexose Correlated Compound (ahcc) (moderate), Adrafinil (moderate) and African Wild Potato (moderate).

By severity: 84 moderate · 19 minor.

From our pharmacist’s overview on the Formoterol page

“Formoterol (Foradil, Perforomist) is the long-acting half of many asthma and COPD inhalers, keeping airways open for hours, and its supplement list is calmer than its length suggests. None of the 103 ingredients on file is rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Formoterol interaction page

One more smart check

Taking Diiodothyronine as Part of a Dietary Supplement Product? Check It for Interactions

We hold 58 real supplement products containing Diiodothyronine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Diiodothyronine. Even though Diiodothyronine itself has no known interaction with Formoterol, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Diiodothyronine and Formoterol 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 Diiodothyronine

Steady interest

#1,118 of 1,452 supplements looked up here in the last 7 days

29 days ago today

Medication Formoterol

Steady interest

#2,162 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. Diiodothyronine is not yet covered by that licensed database, so its write-up cites publicly available medical sources directly (see the references below).
Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Diiodothyronine reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Diiodothyronine and Formoterol records this page draws on were last updated June 22, 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 Dr. Brian Staiger, PharmD, BCPS.

Supplement

About Diiodothyronine

What is Diiodothyronine?

Weight loss and fat burning
Boosting metabolism
Bodybuilding and cutting
Increasing energy

Diiodothyronine (T2) is a thyroid hormone metabolite sold as a fat-loss and metabolism supplement, mostly in the bodybuilding world. Human evidence for its safety and effectiveness is very limited, and because it can affect the thyroid and heart, it should not be used without medical supervision.

Capsules, tablets, powders (sold as 'T2' supplements)

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

Diiodothyronine: dosing

There is no established, medically recommended dose of T2. It has not been studied well enough in humans to define a safe and effective amount.If a product lists a dose on the label, do not assume it is safe just because it is printed there. If you choose to use it despite the limited evidence, do not exceed the label directions and let your healthcare provider monitor you.

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

Read the full Diiodothyronine monograph & all interactions

Medication

About Formoterol Oral Inhalation

What Is Formoterol Oral Inhalation Used For?

Brand names: Foradil Aerolizer, Atimos Modulite, Oxis Turbohaler, Perforomist, Foradil Certihaler

Formoterol fumarate inhalation solution is used for the long-term maintenance treatment of airway narrowing (bronchoconstriction) in adults with COPD, including chronic bronchitis and emphysema. It is taken twice daily — morning and evening — as a regular, ongoing treatment.

Important limits: This medication is not for relieving sudden COPD flare-ups or breathlessness in the moment, and it is not approved to treat asthma. A separate short-acting inhaler should always be on hand for sudden symptoms.

See full Formoterol Oral Inhalation drug information

Keep checking

Other Drugs & Diiodothyronine

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

0Major

0Moderate

0Minor

2,829No known interaction

2,829 No interaction

No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Diiodothyronine list.

See the full Diiodothyronine interactions page

See every supplement checked against Formoterol, ranked by severity

Evidence & sources

Diiodothyronine References

The 3 sources that drive our Diiodothyronine monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing. Diiodothyronine is not covered by the licensed Natural Medicines interaction database, so its page cites these public sources directly.

Thyroid Hormone — MedlinePlus (U.S. National Library of Medicine) Source
Dietary Supplements: What You Need to Know — NIH Office of Dietary Supplements Source
Using Dietary Supplements Wisely — NIH NCCIH Source

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 Diiodothyronine and Formoterol Together: Common Questions

Is it safe to take Diiodothyronine with Formoterol?

We do not list a known interaction between Diiodothyronine and Formoterol. 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.

Does Formoterol interact with any supplements?

Yes. Formoterol has documented interactions with 103 supplements in our database — Diiodothyronine is not one of them. The Formoterol 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

Diiodothyronine monograph Uses, safety profile, and every drug interaction in one place Formoterol Oral Inhalation drug information The full plain-English guide to this medication Formoterol supplement interactions Every supplement checked against Formoterol, 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 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Formoterol and Diiodothyronine?

Our pharmacists answer your medication & supplement questions — free.

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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.