Drug & supplement interaction

Ash + Tasimelteon

Tasimelteon brand names: Hetlioz, Hetlioz Lq.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Ash 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

Ash 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 Ash 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.

Ash safety at a glance

Ash overall Use caution Likely fine in food amounts, but medicinal use lacks strong safety data.
Pregnancy Avoid Not enough safety information, so it is best avoided during pregnancy.
Breastfeeding Avoid No reliable safety data, so avoid while breastfeeding.

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

Still wondering about combining Tasimelteon and Ash? 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. Ash has documented interactions with 2 drug classes — the most serious being antidiabetes drugs (moderate) and antihypertensive 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

Ash Does Interact With Other Medications

Ash has 258 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.

Taking anything else?

Check Another of Your Medications Against Ash

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

What to actually watch for

What Tasimelteon’s Own FDA Label Lists

This is not an interaction — none of it involves Ash. These are the most notable effects listed in the ADVERSE REACTIONS section of Tasimelteon’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. 2 of them are worth acting on rather than waiting out — marked below.

  • Liver problems Worth acting on
  • A higher chance of infection Worth acting on
  • Vivid dreams or nightmares mentioned in 8.5% of FDA reports for Tasimelteon
  • Trouble sleeping mentioned in 19.8% of FDA reports for Tasimelteon
  • Headache mentioned in 6.7% of FDA reports for Tasimelteon

From the ADVERSE REACTIONS section of the FDA label for Tasimelteon. Read the label on DailyMed › Where a percentage is shown, it is the share of 5,765 voluntary FDA FAERS reports for Tasimelteon that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Ash’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Ash side to compare — that is a limit of the record, not a statement that Ash has no side effects.

How to take them

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

At least one FDA label for a product containing Tasimelteon says to take it on an empty stomach. Most supplements — Ash 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 Ash 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.

Everything else you take

See Every Supplement That Interacts With Tasimelteon

This page covers Ash 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 Ash as Part of a Dietary Supplement Product? Check It for Interactions

We hold 8 real supplement products containing Ash, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Ash. Even though Ash 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 Ash 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 Ash
Top half

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

29 days ago today
Medication Tasimelteon
Steady interest

#1,943 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 Ash reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Ash 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.
Data structure & sourcing designed and verified by .
Supplement

About Ash

What is Ash?

Ash
  • Joint pain and arthritis
  • Fever
  • Constipation
  • Fluid retention (diuretic)
  • Bladder and urinary complaints
  • Weight management and blood sugar

Ash (Fraxinus excelsior and related species) is a tree whose leaves, bark, and seeds have a long history in folk medicine for arthritis, fever, and fluid retention. Solid human evidence is limited for nearly all of these uses, so it should not replace proven treatments. Talk with your pharmacist or doctor before using it, especially if you are pregnant, breastfeeding, or taking other medicines.

Fraxinus excelsior · Oleaceae · Leaves, bark, and seeds · Tea, dried leaf, capsules, tinctures, extracts

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

Ash: dosing

There is no well-established standard dose for ash. Amounts vary widely between teas, tinctures, capsules, and extracts.If you choose to use an ash product, follow the directions on the label and do not exceed them.

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

Read the full Ash 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 & Ash

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

0Major
258Moderate
0Minor
2,571No known interaction
Moderate

258 interactions

Showing 60 of 258 moderate interactions — see all 258 on the Ash page.

No interaction 2,571 drugs checked — show the list
Evidence & sources

Ash References

The 3 references that drive our Ash 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. Zulet MA, Navas-Carretero S, Lara y Sánchez D, et al. A Fraxinus excelsior L. seeds/fruits extract benefits glucose homeostasis and adiposity related markers in elderly overweight/obese subjects: a longitudinal, randomized, crossover, double-blind,
  2. Montó F, Arce C, Noguera MA, et al. Action of an extract from the seeds of Fraxinus excelsior L. on metabolic disorders in hypertensive and obese animal models. Food Funct. 2014;5(4):786-96. PubMed
  3. Visen P, Saraswat B, Visen A, et al. Acute effects of Fraxinus excelsior L. seed extract on postprandial glycemia and insulin secretion on healthy volunteers. J Ethnopharmacol. 2009;126(2):226-32. 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 Ash and Tasimelteon Together: Common Questions

Is it safe to take Ash with Tasimelteon?
We do not list a known interaction between Ash 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 Ash 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 Ash 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 Ash and Tasimelteon combination checked?
Interactions in our licensed database are recorded against drug classes. Tasimelteon is filed under 5 classifications, and Ash 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 Ash interact with any other medications?
Yes. Ash has 258 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 — Ash 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

Still Have a Question About Tasimelteon and Ash?

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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.