Drug & supplement interaction

Ecklonia Cava + Letermovir (IV)

Letermovir (IV) brand name: Prevymis.

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 Ecklonia Cava and Letermovir (IV) 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 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

Ecklonia Cava and Letermovir (IV)

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 Letermovir (IV) and Ecklonia Cava 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 Ecklonia Cava at all — not against Letermovir (IV), 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.

Ecklonia Cava safety at a glance

Ecklonia Cava overall Use caution Generally taken short-term in studies, but long-term safety and iodine content are not well established.
Pregnancy Avoid Not enough safety data, and seaweed can carry high iodine levels, so it is best avoided.
Breastfeeding Avoid No reliable safety data during breastfeeding, so avoid use.

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

Still wondering about combining Letermovir (IV) and Ecklonia Cava? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Ecklonia Cava and Letermovir (IV) 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.

  • Diarrhea / Nausea Additional detail

    Ecklonia Cava

    “Orally, nausea, dyspepsia, and diarrhea have been reported by one person each in a clinical trial.”

    Ecklonia Cava · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 106335. Lee DH, Park MY, Shim BJ, et al. Effects of Ecklonia cava polyphenol in individuals with hypercholesterolemia: a pilot study. J Med Food. 2012;15(11):1038-44.

    Letermovir (IV)

    Listed in the ADVERSE REACTIONS section of the FDA label for Letermovir (IV). Read the label on DailyMed ›

Reported for Ecklonia Cava but not commonly for Letermovir (IV): stomach upset and hair loss.

Effects for Letermovir (IV) come from the ADVERSE REACTIONS section of its FDA label; effects for Ecklonia Cava come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

One more smart check

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

We hold 63 real supplement products containing Ecklonia Cava, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Ecklonia Cava. Even though Ecklonia Cava itself has no known interaction with Letermovir (IV), 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 Ecklonia Cava and Letermovir (IV) 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 Ecklonia Cava
Steady interest

#1,133 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Letermovir (IV)
Top 25%

#322 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 Ecklonia Cava reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Ecklonia Cava and Letermovir (IV) 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 Ecklonia Cava

What is Ecklonia Cava?

  • Antioxidant support
  • Heart and circulation health
  • Blood sugar support
  • Inflammation
  • Allergy symptoms
  • Erectile or sexual function

Ecklonia cava is an edible brown seaweed rich in plant compounds called phlorotannins that are studied as antioxidants. Early human and lab research hints at possible benefits for blood vessels, blood sugar, and inflammation, but the evidence is limited and far from proven. Because it contains iodine and has not been well studied for long-term safety, talk with your pharmacist or doctor before using it.

Ecklonia cava · Lessoniaceae · Whole brown seaweed (thallus), used to make extracts · Capsules, tablets, powders, and standardized extracts (often sold under branded names)

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

Ecklonia Cava: dosing

There is no official or standardized dose of Ecklonia cava. Studies have used different branded extracts at different amounts, so there is no single recommended dose for the general public.If you choose to use it, follow the directions on the product label and do not exceed the suggested amount. A pharmacist can help you review the product and decide whether it is appropriate for you, especially if you take other medicines or have a health condition.

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

Read the full Ecklonia Cava monograph & all interactions
Medication

About Letermovir Injection

What Is Letermovir Injection Used For?

Brand name: Prevymis

Prevymis injection is used to prevent cytomegalovirus (CMV) infection and disease in adults and children 6 months of age and older (weighing at least 6 kg) who have received an allogeneic hematopoietic stem cell transplant (HSCT) and are CMV-seropositive (meaning they carry the CMV virus).

Prevymis injection is also used to prevent CMV disease in adults and children 12 years of age and older (weighing at least 40 kg) who have received a kidney transplant and are at high risk — specifically when the donor tested positive for CMV but the recipient tested negative (D+/R-).

See full Letermovir Injection drug information
Keep checking

Other Drugs & Ecklonia Cava

Browse every other medication we’ve checked against Ecklonia Cava — 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 Ecklonia Cava 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 Ecklonia Cava list.

See the full Ecklonia Cava interactions page
See every supplement checked against Letermovir (IV), ranked by severity
Evidence & sources

Ecklonia Cava References

The 1 references that drive our Ecklonia Cava 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. Lee DH, Park MY, Shim BJ, et al. Effects of Ecklonia cava polyphenol in individuals with hypercholesterolemia: a pilot study. J Med Food. 2012;15(11):1038-44.

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 Ecklonia Cava and Letermovir (IV) Together: Common Questions

Is it safe to take Ecklonia Cava with Letermovir (IV)?
We do not list a known interaction between Ecklonia Cava and Letermovir (IV). 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 Ecklonia Cava and Letermovir (IV) 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.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Ecklonia Cava monograph Uses, safety profile, and every drug interaction in one place Letermovir Injection drug information The full plain-English guide to this medication Letermovir (IV) supplement interactions Every supplement checked against Letermovir (IV), 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 1 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Letermovir (IV) and Ecklonia Cava?

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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.