Drug & supplement interaction

Laminaria + Menotropins

Menotropins brand names: Repronex, Menopur.

Moderate Interaction
The bottom line Moderate

Laminaria has a moderate interaction with Menotropins. Due to its iodine content, laminaria might alter the effects of thyroid hormone.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Laminaria and Menotropins

Here is the interaction we found between these two, with the evidence behind it.

Moderate

THYROID HORMONE

Why this applies to Menotropins

Menotropins falls under THYROID HORMONE — the group Laminaria interacts with.

Due to its iodine content, laminaria might alter the effects of thyroid hormone.
Some laminaria supplements contain up to 1000 mcg of iodine. Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking laminaria could theoretically alter the effects of thyroid hormone.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the honest situation: the interaction we have on file is really about thyroid hormone medicines, and Menotropins (Repronex, Menopur) isn't one of those. Menotropins is an injectable fertility hormone made of FSH and LH that your doctor uses to help stimulate the ovaries. It isn't broken down by the same pathways that iodine affects, so kelp wouldn't directly speed it up or slow it down.

That said, the iodine in Laminaria can be high and unpredictable, and it can nudge your thyroid toward being over- or underactive. Since healthy thyroid function matters a lot during fertility treatment, an out-of-balance thyroid could work against your cycle. This is theoretical and based on weak evidence, so don't panic. Just talk with your fertility doctor or pharmacist before adding any kelp product.

References
  1. Eliason BC. Transient hyperthyroidism in a patient taking dietary supplements containing kelp. J Am Board Fam Pract 1998;11:478-80. PubMed
  2. Miyai K, Tokushige T, Kondo M; Iodine Research Group. Suppression of thyroid function during ingestion of seaweed "Kombu" (Laminaria japonoca) in normal Japanese adults. Endocr J. 2008 Dec;55(6):1103-8. Epub 2008 Aug 9.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Laminaria Also Interacts With Other Medications

Laminaria has 68 moderate known drug interactions in our database — the Menotropins one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Laminaria

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

Everything else you take

See Every Supplement That Interacts With Menotropins

This page covers Laminaria only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Menotropins page lists 21 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Tiratricol (major), Acetyl-l-carnitine (moderate), Alpha-lipoic Acid (moderate), Ascophyllum Nodosum (moderate) and Ashwagandha (moderate).

By severity: 1 major · 19 moderate · 1 minor.

From our pharmacist’s overview on the Menotropins page

“If you are using menotropins (Menopur, Repronex) for fertility treatment, I would hold off on every one of the 21 supplements on this page until your prescriber weighs in. All of them touch thyroid hormone activity in one direction or the other, and steady thyroid function matters when you are trying to get a cycle to succeed.”

Reviewed by 2 · Jul 18, 2026

Open the Menotropins interaction page

One more smart check

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

We hold 229 real supplement products containing Laminaria, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Laminaria. Your product may carry other ingredients that interact with Menotropins too, on top of Laminaria — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Laminaria and Menotropins 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 Laminaria
Steady interest

#1,017 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Menotropins
Steady interest

#1,483 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.

Supplement

About Laminaria

What is Laminaria?

  • Source of dietary iodine
  • Thyroid support
  • Cervical dilation (medical procedure)
  • Weight management
  • Digestive and detox supplements
  • General nutrition (vitamins and minerals)

Laminaria is a type of brown seaweed (kelp) that is very rich in iodine and is also used in medical settings as a natural cervical dilator. Because its iodine content can be high and variable, supplements may upset thyroid function, so it should be used cautiously and under professional guidance. Always talk with your pharmacist or doctor before using kelp products, especially if you have a thyroid condition.

Read the full Laminaria monograph & all interactions
Keep checking

Other Drugs & Laminaria

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

0Major
68Moderate
0Minor
2,761No known interaction
Moderate

68 interactions

Showing 60 of 68 moderate interactions — see all 68 on the Laminaria page.

No interaction 2,761 drugs checked — show the list
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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Pharmacist Counseling Corner

Taking Laminaria and Menotropins Together: Common Questions

Can you take Laminaria with Menotropins?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Laminaria and Menotropins interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

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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.