Diiodothyronine + Tasimelteon
Tasimelteon brand names: Hetlioz, Hetlioz Lq.
We found no known interaction between Diiodothyronine and Tasimelteon 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 Tasimelteon states a food rule worth keeping to.
Diiodothyronine and Tasimelteon
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 Tasimelteon 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 Tasimelteon, 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
Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
Some Tasimelteon Products Have a Food Rule — Diiodothyronine Should Not Break It
At least one FDA label for a product containing Tasimelteon says to take it on an empty stomach. Most supplements — Diiodothyronine included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Tasimelteon on its own and move Diiodothyronine 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 Tasimelteon 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.
2 DOSAGE AND ADMINISTRATION Indicated Population Dosage Form Body Weight Recommended Dosage Non-24 ( 2.2 ) Adults Capsules Not applicable 20 mg one hour prior to bedtime Nighttime sleep disturbances in SMS ( 2.3 ) Patients 16 years of age and older Capsules Not applicable 20 mg one hour prior to bedtime Pediatric Patients 3 to 15 years of age Oral Suspension ≤ 28 kg 0.7 mg/kg one hour before bedti
From the Dosage and Administration section of the FDA label we read for Tasimelteon — 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.
See Every Supplement That Interacts With Tasimelteon
This page covers Diiodothyronine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tasimelteon page lists 218 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Grapefruit (major).
By severity: 9 major · 166 moderate · 43 minor.
From our pharmacist’s overview on the Tasimelteon page
“Tasimelteon (Hetlioz) resets the body clock in people with non-24-hour sleep-wake disorder, and the sleep aids they often reach for, melatonin and kava among them, sit on an interaction list that deserves real respect. Nine of the 218 ingredients on file rate major, mostly in two directions: sedatives like kava stack drowsiness onto a…”
Reviewed by 2 · Jul 18, 2026
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 Tasimelteon, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:
Where Diiodothyronine and Tasimelteon 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.
#1,094 of 1,452 supplements looked up here in the last 7 days
#1,387 of 2,830 medications looked up here in the last 7 days
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 20, 2026. The Diiodothyronine and Tasimelteon 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.
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.
About Tasimelteon
What Is Tasimelteon Used For?
Brand names: Hetlioz, Hetlioz Lq
Tasimelteon capsules are approved to treat Non-24-Hour Sleep-Wake Disorder (Non-24) in adults. Non-24 is a condition where the body's internal clock does not align with the normal 24-hour day, causing sleep and wake times to shift continuously.
Hetlioz capsules are also approved to treat nighttime sleep disturbances in Smith-Magenis Syndrome (SMS) in patients 16 years of age and older. Hetlioz LQ oral suspension is approved specifically for nighttime sleep disturbances in SMS in pediatric patients ages 3 to 15 years.
Most-Reported Side Effects for Tasimelteon
From FAERS, the FDA’s public side-effect reporting system (5,770 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.
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.
No drugs match “”.
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.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Abemaciclib ›
- Ivermectin ›
- Sertraline ›
- Testosterone ›
- Acetaminophen ›
- Losartan Potassium ›
- Aspirin ›
- Rosuvastatin ›
- Metoprolol ›
- Escitalopram ›
- Clopidogrel ›
- Rivaroxaban ›
- Atorvastatin ›
- Methamphetamine ›
- Tirzepatide ›
- Docusate ›
- Ibuprofen ›
- Warfarin Sodium ›
- Tadalafil ›
- Sumatriptan ›
- Valacyclovir ›
- Hydroxyurea ›
- Isotretinoin ›
- Prednisone ›
- Semaglutide ›
- Metformin ›
- Lisdexamfetamine ›
- Propranolol ›
- Amitriptyline ›
- Amlodipine Besylate ›
- Methotrexate ›
- Amphetamine ›
- Amoxicillin ›
- Lisinopril ›
- Bupropion ›
- Fluoxetine ›
- Bendamustine ›
- Doxycycline ›
- Pregabalin ›
- Lamotrigine ›
- Azithromycin ›
- Acyclovir ›
- Gabapentin ›
- Levothyroxine, Liothyronine ›
- Dextroamphetamine ›
- Naproxen ›
- Quetiapine ›
- Clonazepam ›
- Omeprazole ›
- Buspirone ›
- Duloxetine ›
- Letrozole ›
- Acetaminophen, Codeine ›
- Citalopram ›
- Methylene Blue ›
Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Diiodothyronine list.
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.
Taking Diiodothyronine and Tasimelteon Together: Common Questions
Is it safe to take Diiodothyronine with Tasimelteon?
Should I take Diiodothyronine and Tasimelteon at the same time of day?
Does Tasimelteon interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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Still Have a Question About Tasimelteon and Diiodothyronine?
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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.