Drug & supplement interaction

Sea Moss + Hydrochlorothiazide

Hydrochlorothiazide brand names: Esidrix, Hydro, Microzide, HydroDiuril, Hydro-D, and others.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Sea Moss and Hydrochlorothiazide 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

Sea Moss and Hydrochlorothiazide

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 Hydrochlorothiazide and Sea Moss 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.

Sea Moss safety at a glance

Sea Moss overall Use caution Generally seen as food, but variable iodine levels and possible heavy-metal content warrant caution.
Pregnancy Likely Safe When used in food amounts. There is insufficient reliable information available about the safety of using larger amounts; avoid using. Read the full pregnancy detail
Breastfeeding Likely Safe When used in food amounts. There is insufficient reliable information available about the safety of using larger amounts; avoid using. 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 Hydrochlorothiazide and Sea Moss? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Hydrochlorothiazide

Interactions in our licensed database are recorded against drug classes, not just single drug names. Hydrochlorothiazide is filed under 8 classifications — including thiazide diuretics, diuretic drugs, organic anion transporter 3 (oat3) substrates. Sea Moss has documented interactions with 3 drug classes — the most serious being amiodarone (cordarone) (moderate), antithyroid drugs (moderate) and thyroid hormone (moderate) — and none of Hydrochlorothiazide’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

Sea Moss Does Interact With Other Medications

Sea Moss has 22 moderate known drug interactions in our database — Hydrochlorothiazide 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 Sea Moss

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

What to actually watch for

No Interaction Found — But Data Suggests Sea Moss and Hydrochlorothiazide 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.

  • Constipation / Diarrhea reported in 5.6% of FDA reports for Hydrochlorothiazide Additional detail

    Sea Moss

    “Orally, see moss has been reported to cause constipation and diarrhea in one observational study.”

    Sea Moss · Natural Medicines adverse-effect record, reported in constipation.

    1 source cited
    1. 109121. Palmieri B, Vadalà M, Laurino C. Clinical effects of overwintered-stressed Chondrus Crispus and non-overwintered-stressed Chondrus crispus dietary supplementations. Asian J Med Sci. 2018; 9(6): 7-13. DOI

    Hydrochlorothiazide

    Listed in the ADVERSE REACTIONS section of the FDA label for Hydrochlorothiazide, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Effects for Hydrochlorothiazide come from the ADVERSE REACTIONS section of its FDA label; effects for Sea Moss come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 209,395 voluntary FDA FAERS reports for Hydrochlorothiazide that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Sea Moss in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When used in food amounts. There is insufficient reliable information available about the safety of using larger amounts; 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

From our Q&A

Questions About Sea Moss or Hydrochlorothiazide

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Sea Moss or Hydrochlorothiazide, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Hydrochlorothiazide

This page covers Sea Moss only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydrochlorothiazide page lists 230 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Asarabacca (major) and Dolomite (major).

By severity: 10 major · 195 moderate · 25 minor.

From our pharmacist’s overview on the Hydrochlorothiazide page

“Hydrochlorothiazide sits at the strong end of the caution scale for supplement interactions, and the small group of major-rated entries deserves a careful read before everything else on the page. Most of what appears here either adds to the pill's blood-pressure-lowering effect or piles onto its diuretic action, pushing fluid and potas…”

Reviewed by 2 · Jul 18, 2026

Open the Hydrochlorothiazide interaction page

How much people look this up

Where Sea Moss and Hydrochlorothiazide 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 Sea Moss
Top half

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

29 days ago today
Medication Hydrochlorothiazide
Top 5%

#122 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 Sea Moss reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Sea Moss and Hydrochlorothiazide 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 Sea Moss

What is Sea Moss?

Sea Moss
  • Source of iodine and minerals
  • Thyroid support
  • Respiratory issues and cough
  • Digestive support
  • Skin and hair health
  • General immune and antioxidant support

Sea moss is a type of red seaweed that is naturally rich in iodine and several minerals, and it is popular as a 'whole-food' supplement. Strong human evidence for most of its health claims is lacking, and its high and variable iodine content can be a real concern, especially for people with thyroid problems. Talk to your pharmacist or doctor before using it, particularly if you are pregnant, breastfeeding, or have a thyroid condition.

Chondrus crispus · Gigartinaceae · Whole dried seaweed (thallus) · Gel, dried raw seaweed, capsules, powder, gummies, drinks, skin products

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

Sea Moss: dosing

There is no established, standardized dose for sea moss. Iodine content varies widely between products, which makes consistent dosing difficult and increases the risk of getting too much.If you choose to use it, follow the directions on the product label and start low.

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

Read the full Sea Moss monograph & all interactions
Medication

About Hydrochlorothiazide

What Is Hydrochlorothiazide Used For?

Brand names: Esidrix, Hydro, Microzide, HydroDiuril, Hydro-D, Oretic, Aquazide H, Aquazide, HCTZ

Hydrochlorothiazide treats high blood pressure (hypertension) in adults and children, either alone or combined with other blood pressure medicines. Lowering blood pressure reduces the risk of strokes and heart attacks.

It also treats edema (fluid buildup) linked to congestive heart failure, hepatic cirrhosis (liver scarring), and kidney conditions including nephrotic syndrome. Hydrochlorothiazide tablets are additionally indicated for edema caused by corticosteroid or estrogen therapy, and edema from acute glomerulonephritis or chronic renal failure. Inzirqo (the oral suspension) is specifically approved for both hypertension and edema in adult and pediatric patients.

Most-Reported Side Effects for Hydrochlorothiazide

From FAERS, the FDA’s public side-effect reporting system (209,395 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 13,772 reports
Nausea 13,724 reports
Diarrhea 11,763 reports
Dizziness 11,243 reports
Headache 10,766 reports
See full Hydrochlorothiazide drug information
Keep checking

Other Drugs & Sea Moss

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

0Major
22Moderate
0Minor
2,807No known interaction
Moderate

22 interactions

No interaction 2,807 drugs checked — show the list
Evidence & sources

Sea Moss References

The 3 references that drive our Sea Moss 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. Darias-Rosales J, Rubio C, Gutiérrez ÁJ, Paz S, Hardisson A. Risk assessment of iodine intake from the consumption of red seaweeds (Palmaria palmata and Chondrus crispus). Environ Sci Pollut Res Int 2020;27(36):45737-45741. PubMed
  2. U.S. Department of Agriculture (USDA). Agricultural Research Service. FoodData Central. Seaweed, irishmoss, raw. April 2019. Available at: https://fdc.nal.usda.gov/fdc-app.html#/food-details/168456/nutrients. Accessed Aug. 30, 2022.
  3. Palmieri B, Vadalà M, Laurino C. Clinical effects of overwintered-stressed Chondrus Crispus and non-overwintered-stressed Chondrus crispus dietary supplementations. Asian J Med Sci. 2018; 9(6): 7-13. 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 Sea Moss and Hydrochlorothiazide Together: Common Questions

Is it safe to take Sea Moss with Hydrochlorothiazide?
We do not list a known interaction between Sea Moss and Hydrochlorothiazide. 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 Sea Moss and Hydrochlorothiazide 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.
How was the Sea Moss and Hydrochlorothiazide combination checked?
Interactions in our licensed database are recorded against drug classes. Hydrochlorothiazide is filed under 8 classifications, and Sea Moss has documented interactions with 3 drug classes — none of Hydrochlorothiazide'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 Sea Moss interact with any other medications?
Yes. Sea Moss has 22 documented drug interactions in our database — Hydrochlorothiazide 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 Hydrochlorothiazide interact with any supplements?
Yes. Hydrochlorothiazide has documented interactions with 230 supplements in our database — Sea Moss is not one of them. The Hydrochlorothiazide 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 Hydrochlorothiazide and Sea Moss?

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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.