Drug & supplement interaction

Isopropylnorsynephrine + Tasimelteon

Tasimelteon brand names: Hetlioz, Hetlioz Lq.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Isopropylnorsynephrine 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.

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Interaction report

Isopropylnorsynephrine 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 Isopropylnorsynephrine 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.

Isopropylnorsynephrine safety at a glance

Isopropylnorsyneph... overall Use caution It is a poorly studied synthetic stimulant with unknown long-term safety in humans.
Pregnancy Possibly Unsafe When used orally. Isopropylnorsynephrine has been associated with vomiting, hypertension, blurred vision, palpitations, and respiratory distress. When used in c... Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used orally. Isopropylnorsynephrine has been associated with vomiting, hypertension, blurred vision, palpitations, and respiratory distress. When used in c... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Tasimelteon and Isopropylnorsynephrine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Tasimelteon

Interactions in our licensed database are recorded against drug classes, not just single drug names. Tasimelteon is filed under 5 classifications — including cytochrome p450 1a2 (cyp1a2) substrates, cytochrome p450 1a2 (cyp1a2) substrates, cns depressants. Isopropylnorsynephrine has documented interactions with 2 drug classes — the most serious being antihypertensive drugs (moderate) and stimulant drugs (moderate) — and none of Tasimelteon’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

Isopropylnorsynephrine Does Interact With Other Medications

Isopropylnorsynephrine has 344 moderate known drug interactions in our database — Tasimelteon isn’t one of them. If you take anything else, check it against the full list below.

Moderate 344 No known interaction 2,486 (incl. Tasimelteon)
Taking anything else?

Check Another of Your Medications Against Isopropylnorsynephrine

Covers the 2,830 medications we’ve checked against Isopropylnorsynephrine. Pick one to open its full report.

What to actually watch for

What Isopropylnorsynephrine Itself Has Been Linked To

This is not an interaction — nothing below involves Tasimelteon. It is the side-effect record for Isopropylnorsynephrine on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Isopropylnorsynephrine, this list is the first place to look. 2 entries are worth acting on rather than waiting out — marked below.

  • Raised blood pressure Worth acting on Additional detail

    “Orally and parenterally, isopropylnorsynephrine is generally regarded as unsafe.

    Serious Adverse Effects (Rare):

    Orally: Hypertension, palpitations, respiratory distress, and vomiting. Stroke and cardiac arrest have been reported when used with other stimulants or intensive exercise.”

    Isopropylnorsynephrine · Natural Medicines adverse-effect record, reported in acute respiratory distress syndrome (ards).

    “Orally, isopropylnorsynephrine has been associated with hypertension and palpitations. When used in combination with stimulants or intensive exercise, isopropylnorsynephrine has been associated with adverse cardiovascular events such as stroke and cardiac arrest.”

    Isopropylnorsynephrine · Natural Medicines adverse-effect record, reported in cardiac arrest.

    2 sources cited
    1. 21079. Venhuis B, Keizers P, van Riel A, de Kaste D. A cocktail of synthetic stimulants found in a dietary supplement associated with serious adverse events. Drug Test Anal. 2014 Jun;6(6):578-81. doi: 10.1002/dta.1664. Epub 2014 May 6. PubMed
    2. 104949. Cohen PA, Travis JC, Vanhee C, Ohana D, Venhuis BJ. Nine prohibited stimulants found in sports and weight loss supplements: deterenol, phenpromethamine (Vonedrine), oxilofrine, octodrine, beta-methylphenylethylamine (BMPEA), 1,3-dimethylamylamine (1,3-DMA
  • Shortness of breath Worth acting on Additional detail

    “Orally, isopropylnorsynephrine has been associated with respiratory distress.”

    Isopropylnorsynephrine · Natural Medicines adverse-effect record, reported in acute respiratory distress syndrome (ards).

    2 sources cited
    1. 21079. Venhuis B, Keizers P, van Riel A, de Kaste D. A cocktail of synthetic stimulants found in a dietary supplement associated with serious adverse events. Drug Test Anal. 2014 Jun;6(6):578-81. doi: 10.1002/dta.1664. Epub 2014 May 6. PubMed
    2. 104949. Cohen PA, Travis JC, Vanhee C, Ohana D, Venhuis BJ. Nine prohibited stimulants found in sports and weight loss supplements: deterenol, phenpromethamine (Vonedrine), oxilofrine, octodrine, beta-methylphenylethylamine (BMPEA), 1,3-dimethylamylamine (1,3-DMA
  • A fast or pounding heartbeat Additional detail

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

  • Vomiting Additional detail

    “Orally, isopropylnorsynephrine has been associated with vomiting.”

    Isopropylnorsynephrine · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    2 sources cited
    1. 21079. Venhuis B, Keizers P, van Riel A, de Kaste D. A cocktail of synthetic stimulants found in a dietary supplement associated with serious adverse events. Drug Test Anal. 2014 Jun;6(6):578-81. doi: 10.1002/dta.1664. Epub 2014 May 6. PubMed
    2. 104949. Cohen PA, Travis JC, Vanhee C, Ohana D, Venhuis BJ. Nine prohibited stimulants found in sports and weight loss supplements: deterenol, phenpromethamine (Vonedrine), oxilofrine, octodrine, beta-methylphenylethylamine (BMPEA), 1,3-dimethylamylamine (1,3-DMA

Everything above comes from the Natural Medicines adverse-effect record for Isopropylnorsynephrine — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Tasimelteon’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Tasimelteon column appears here.

Special populations

Isopropylnorsynephrine in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Unsafe

When used orally. Isopropylnorsynephrine has been associated with vomiting, hypertension, blurred vision, palpitations, and respiratory distress. When used in combination with stimulants or intensive exercise, isopropylnorsynephrine has been associated with adverse cardiovascular events such as stroke and cardiac arrest. Avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

How to take them

Some Tasimelteon Products Have a Food Rule — Isopropylnorsynephrine Should Not Break It

At least one FDA label for a product containing Tasimelteon says to take it on an empty stomach. Most supplements — Isopropylnorsynephrine 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 Isopropylnorsynephrine 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. See the Tasimelteon drug page ›

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 Tasimelteon

This page covers Isopropylnorsynephrine 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

Open the Tasimelteon interaction page

One more smart check

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

We hold 48 real supplement products containing Isopropylnorsynephrine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Isopropylnorsynephrine. Even though Isopropylnorsynephrine 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:

How much people look this up

Where Isopropylnorsynephrine 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.

Supplement Isopropylnorsynephrine
Steady interest

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

29 days ago today
Medication Tasimelteon
Steady interest

#2,172 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 Isopropylnorsynephrine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Isopropylnorsynephrine and Tasimelteon 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 Isopropylnorsynephrine

What is Isopropylnorsynephrine?

  • Weight loss and fat burning
  • Pre-workout energy and stimulation
  • Topical fat reduction (creams and gels)
  • Appetite suppression
  • Athletic performance

Isopropylnorsynephrine is a synthetic stimulant chemically related to synephrine, marketed mainly in weight-loss and pre-workout supplements. It has very little human safety or effectiveness research, and as a stimulant it may raise heart rate and blood pressure, so caution is strongly advised. Talk with a pharmacist or doctor before using any product that contains it.

Synthetic compound (not a plant part) · Capsules, tablets, powders, and topical gels or creams (often in fat-loss and pre-workout products)

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

Isopropylnorsynephrine: dosing

There is no established or proven safe dose for isopropylnorsynephrine. No official health authority has set a recommended amount, and studies do not provide reliable dosing guidance.If a product contains it, follow the label instructions and do not exceed them.

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

Read the full Isopropylnorsynephrine monograph & all interactions
Medication

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.

Insomnia 728 reports
Middle insomnia 414 reports
Somnolence 408 reports
Headache 386 reports
Nightmare 268 reports
See full Tasimelteon drug information
Keep checking

Other Drugs & Isopropylnorsynephrine

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

0Major
344Moderate
0Minor
2,485No known interaction
344 Moderate 2,485 No interaction
Moderate

344 interactions

Showing 60 of 344 moderate interactions — see all 344 on the Isopropylnorsynephrine page.

No interaction 2,485 drugs checked — show the list

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

Showing the 60 most looked-up of 2,485 medications checked with no known interaction — see the full Isopropylnorsynephrine list.

See the full Isopropylnorsynephrine interactions page
See every supplement checked against Tasimelteon, ranked by severity
Evidence & sources

Isopropylnorsynephrine References

The 3 references that drive our Isopropylnorsynephrine 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. Venhuis B, Keizers P, van Riel A, de Kaste D. A cocktail of synthetic stimulants found in a dietary supplement associated with serious adverse events. Drug Test Anal. 2014 Jun;6(6):578-81. doi: 10.1002/dta.1664. Epub 2014 May 6. PubMed
  2. Cohen PA, Travis JC, Vanhee C, Ohana D, Venhuis BJ. Nine prohibited stimulants found in sports and weight loss supplements: deterenol, phenpromethamine (Vonedrine), oxilofrine, octodrine, beta-methylphenylethylamine (BMPEA), 1,3-dimethylamylamine (1,3-DMA
  3. Anderson WG. The sympathomimetic activity of N-isopropyloctopamine in vitro. J Pharmacol Exp Ther 1983;225(3):553-8. DOI

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 Isopropylnorsynephrine and Tasimelteon Together: Common Questions

Is it safe to take Isopropylnorsynephrine with Tasimelteon?
We do not list a known interaction between Isopropylnorsynephrine and Tasimelteon. 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.
Should I take Isopropylnorsynephrine and Tasimelteon at the same time of day?
At least one FDA label for a product containing Tasimelteon 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 Tasimelteon on its own and move Isopropylnorsynephrine 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 Isopropylnorsynephrine and Tasimelteon combination checked?
Interactions in our licensed database are recorded against drug classes. Tasimelteon is filed under 5 classifications, and Isopropylnorsynephrine has documented interactions with 2 drug classes — none of Tasimelteon'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 Isopropylnorsynephrine interact with any other medications?
Yes. Isopropylnorsynephrine has 344 documented drug interactions in our database — Tasimelteon 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 Tasimelteon interact with any supplements?
Yes. Tasimelteon has documented interactions with 218 supplements in our database — Isopropylnorsynephrine is not one of them. The Tasimelteon 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

Isopropylnorsynephrine monograph Uses, safety profile, and every drug interaction in one place Tasimelteon drug information The full plain-English guide to this medication Tasimelteon supplement interactions Every supplement checked against Tasimelteon, 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 Tasimelteon and Isopropylnorsynephrine?

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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.