T-W Ingredients & Drug Interactions
by Pure Herbs
What is this page for?
First and foremost: checking T-W against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.
Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy
T-W is a dietary supplement by Pure Herbs with 4 active ingredients. Its ingredients are commonly taken for thyroid support, iodine source, weight management.Based on those ingredients, 1,126 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Bladderwrack Algae Extract, Wild Lettuce aerial parts extract, Dulse Leaf Extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against T-W by Pure Herbs
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AI summaries are generated from our interaction database for education only — always confirm with your pharmacist. How we use AI
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HelloPharmacist Scorecard of T-W by Pure Herbs
Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.
What’s inside
Low disclosure
Pure Herbs T-W is a liquid supplement with four active ingredients: bladderwrack algae extract, Irish moss extract (also called sea moss), dulse leaf extract, and wild lettuce aerial parts extract. These are all plant-derived sea vegetables and herbal materials.
The product contains no inactive ingredients listed. Each of the seaweeds — bladderwrack, Irish moss, and dulse — is rich in iodine and minerals, while wild lettuce has traditionally been used for its potential sedative properties.
The exact amounts of each ingredient are not specified on the label provided.
Does it work?
Not established
The evidence supporting this product's effectiveness is not established in the data we hold. Bladderwrack has been studied for aging skin, cardiovascular disease, constipation, diarrhea, and indigestion — all rated as having insufficient reliable evidence to rate its benefit.
Irish moss shows insufficient reliable evidence for fatigue, muscle strength, chronic pain, quality of life, and iodine deficiency. Dulse similarly lacks reliable evidence for high cholesterol and iodine deficiency.
Wild lettuce has no effectiveness ratings in our data. In short, we don't have evidence that this product works for any specific condition.
How safe is it?
Well-documented data
Oral use of bladderwrack may be unsafe due to its variable, high iodine content, which can disrupt thyroid function and the plant may concentrate heavy metals. Irish moss is generally seen as a food but has variable iodine levels and possible heavy-metal content.
Dulse is generally safe in food amounts, but concentrated supplements may contain high and unpredictable iodine and potassium levels and should be used cautiously. Wild lettuce has limited human safety data, and large doses have been linked to sweating, rapid heartbeat, dizziness, ringing in the ears, vision problems, and in extreme cases respiratory depression or coma.
During pregnancy, bladderwrack is rated unsafe due to excess iodine and possible heavy metals; Irish moss is rated likely safe but iodine and contaminants are unpredictable so it is best avoided; dulse safety data is incomplete; wild lettuce is rated unsafe due to insufficient safety information. During breastfeeding, bladderwrack and wild lettuce should be avoided — iodine passes into breast milk and may affect the baby's thyroid, and there is no reliable safety data for wild lettuce.
Irish moss and dulse have limited data but excess iodine can affect a nursing baby, so avoid supplement doses and talk with your doctor.
Meds to double-check
Moderate interaction found
Before taking this product, double-check with your doctor or pharmacist if you take lithium (risk of high iodine levels and thyroid problems), antithyroid drugs, thyroid hormone replacements, or amiodarone — all have Moderate interaction risks. Also check if you're on digoxin, potassium-sparing diuretics, ACE inhibitors, ARBs (angiotensin receptor blockers), blood thinners (anticoagulants or antiplatelets), sedating drugs, or anticholinergic drugs.
No interactions are documented for the ingredients we could not check.
The bottom line
Scorecard at a glanceFormula with limited ingredient disclosure with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.
This product is meant to contain sea vegetables and an herbal extract, but we don't have evidence it works for any specific condition. Because it's high in iodine and carries Moderate interaction risks with thyroid and heart medications, as well as other drugs, it's not for people taking lithium, antithyroid drugs, thyroid replacements, amiodarone, digoxin, or potassium-regulating drugs.
It's also unsafe in pregnancy and breastfeeding. Talk with your doctor or pharmacist before starting it, especially if you take any prescription medications or have a thyroid condition.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 4 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Nov 22, 2022.
This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed
General information
Key facts about T-W, straight from the product label.
| Brand | Pure Herbs |
|---|---|
| Net contents | 1 Fluid Ounce(s); 30 mL |
| Market status | On market |
| Date entered into DSLD | Nov 22, 2022 |
| DSLD ID | 279957 |
| Product type | Botanical |
| Supplement form | Liquid |
| Dietary claims / uses | All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years), Women (not pregnant or lactating) |
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.
Supplement Facts
The label details for T-W by Pure Herbs, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Proprietary Blend | 1907 mg | -- |
| Bladderwrack Algae Extract | 0 NP | -- |
| Irish Moss Extract | 0 NP | -- |
| Dulse Leaf Extract | 0 NP | -- |
| Wild Lettuce aerial parts extract | 0 NP | -- |
Other ingredients: None
Tap any ingredient to jump to its full detail below.
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Suggested/Recommended/Usage/Directions
Directions: For adults, mix 2 mL (abt. 1/2 tsp) of extract in 2 fl. oz (60 mL) water one time daily preferably with a meal.
Shake well before use
Formulation
To support healthy thyroid function.
FDA Disclaimer Statement
This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
Precautions
Warning: Not intended for use by pregnant or nursing women. If you have a medical condition or are taking medication, consult your doctor prior to use.
Discontinue use and consult with your doctor if any adverse reactions occur.
Keep out of reach of children
Brand IP Statement(s)
Pure Herbs, Ltd. Natural Herbal Extracts
FDA Statement of Identity
Dietary Supplement
General Statements
"No expense has been spared to provide the finest nature has to offer."
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
T-W by Pure Herbs label
The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.
Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.
View the full label (PDF)The Ingredients in T-W by Pure Herbs
These are the 4 active ingredients this product is made of. Select any to open its full monograph.
Serving size2 mL Dosage formLiquid Servings per container15 Amounts shown are per serving.
Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.
Proprietary Blend
Other (inactive) ingredients: None. These complete the product’s ingredient list but are not active constituents.
T-W by Pure Herbs Drug Interactions
HelloPharmacist Interaction Report
Pure Herbs T-W interacts with medications through its bladderwrack algae extract, Irish moss extract, dulse leaf extract, and wild lettuce aerial parts extract.
The most serious interaction is a Moderate-severity risk of high iodine levels and thyroid disruption when bladderwrack is combined with lithium — a case report documents hyperthyroidism in a patient taking both.
Read the full breakdown — every affected drug type, severity by severity
Bladderwrack, Irish moss, and dulse all contain significant iodine and interact Moderately with antithyroid drugs, amiodarone, and thyroid hormone replacements, potentially altering their effects or causing abnormal thyroid function. Bladderwrack also has Minor interactions with three enzyme systems (CYP2D6, CYP2C9, and CYP3A4 substrates) and with blood thinners (anticoagulants and antiplatelets).
Dulse adds Minor interactions with potassium-regulating drugs: ACE inhibitors, ARBs (angiotensin receptor blockers), and potassium-sparing diuretics — all due to its high potassium content — as well as a Moderate interaction with digoxin. Wild lettuce has Moderate interactions with sedating drugs (CNS depressants) and anticholinergic drugs.
Altogether, these interactions span 1,127 individual medications. Check your exact prescriptions with the search tool on this page before starting.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against T-W?
Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.
Go to the checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in T-W interact with 1,126 drugs. Click any drug to see the details.
4 of the 4 ingredients in T-W interact with drugs. Each result below shows which ingredient is responsible. Bladderwrack Algae Extract Wild Lettuce aerial parts extract Dulse Leaf Extract Irish Moss Extract
Isopropamide, ProchlorperazineCombid
How Isopropamide, Prochlorperazine interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractAnticholinergic Drugs Moderate
Interaction Summary
Studies report varying evidence on whether or not wild lettuce contains hyoscyamine, an anticholinergic drug.
Read the full Wild Lettuce Aerial Parts Extract + Isopropamide, Prochlorperazine interactionIsopropamide, TrifluoperazineStelabid Forte, Stelabid No 1, Stelabid No 2
How Isopropamide, Trifluoperazine interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractAnticholinergic Drugs Moderate
Interaction Summary
Studies report varying evidence on whether or not wild lettuce contains hyoscyamine, an anticholinergic drug.
Read the full Wild Lettuce Aerial Parts Extract + Isopropamide, Trifluoperazine interactionKetazolamLoftran
How Ketazolam interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractCns Depressants Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Ketazolam interactionLamotrigineLamictal
How Lamotrigine interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractCns Depressants Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Lamotrigine interactionLasmiditan SuccinateReyvow
How Lasmiditan Succinate interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractCns Depressants Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Lasmiditan Succinate interactionLemborexantDayvigo
How Lemborexant interacts with T-W — through 2 ingredients. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractCns Depressants Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Lemborexant interactionBladderwrack Algae ExtractCytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.
Read the full Bladderwrack Algae Extract + Lemborexant interactionLetibotulinumtoxina-wlbgLetybo
How Letibotulinumtoxina-wlbg interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractAnticholinergic Drugs Moderate
Interaction Summary
Studies report varying evidence on whether or not wild lettuce contains hyoscyamine, an anticholinergic drug.
Read the full Wild Lettuce Aerial Parts Extract + Letibotulinumtoxina-wlbg interactionLevetiracetamElepsia XR, Keppra, Spritam
How Levetiracetam interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractCns Depressants Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Levetiracetam interactionLevomethadylOrlaam
How Levomethadyl interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractCns Depressants Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Levomethadyl interactionLevorphanolLevo-Dromoran
How Levorphanol interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractCns Depressants Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Levorphanol interactionLevothyroxineEltroxin, Estre, Euthyrox, Levo-T, Levolet, Levothroid +5 more
How Levothyroxine interacts with T-W — through 3 ingredients. Tap an ingredient for the detail:
Bladderwrack Algae ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Algae Extract + Levothyroxine interactionDulse Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Theoretically, due to its iodine content, dulse might alter the effects of thyroid hormone.
Read the full Dulse Leaf Extract + Levothyroxine interactionIrish Moss ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, sea moss might alter the effects of thyroid hormone.
Read the full Irish Moss Extract + Levothyroxine interactionLevothyroxine SodiumErmez, Thyquidity, Tirosint-Sol
How Levothyroxine Sodium interacts with T-W — through 3 ingredients. Tap an ingredient for the detail:
Bladderwrack Algae ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Algae Extract + Levothyroxine Sodium interactionDulse Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Theoretically, due to its iodine content, dulse might alter the effects of thyroid hormone.
Read the full Dulse Leaf Extract + Levothyroxine Sodium interactionIrish Moss ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, sea moss might alter the effects of thyroid hormone.
Read the full Irish Moss Extract + Levothyroxine Sodium interactionLevothyroxine, LiothyronineArmour Thyroid
How Levothyroxine, Liothyronine interacts with T-W — through 3 ingredients. Tap an ingredient for the detail:
Bladderwrack Algae ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Algae Extract + Levothyroxine, Liothyronine interactionDulse Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Theoretically, due to its iodine content, dulse might alter the effects of thyroid hormone.
Read the full Dulse Leaf Extract + Levothyroxine, Liothyronine interactionIrish Moss ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, sea moss might alter the effects of thyroid hormone.
Read the full Irish Moss Extract + Levothyroxine, Liothyronine interactionLiothyronineCytomel
How Liothyronine interacts with T-W — through 3 ingredients. Tap an ingredient for the detail:
Bladderwrack Algae ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Algae Extract + Liothyronine interactionDulse Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Theoretically, due to its iodine content, dulse might alter the effects of thyroid hormone.
Read the full Dulse Leaf Extract + Liothyronine interactionIrish Moss ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, sea moss might alter the effects of thyroid hormone.
Read the full Irish Moss Extract + Liothyronine interactionLiotrixEuthroid 1, Euthroid 1/2, Euthroid 3
How Liotrix interacts with T-W — through 3 ingredients. Tap an ingredient for the detail:
Bladderwrack Algae ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Algae Extract + Liotrix interactionDulse Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Theoretically, due to its iodine content, dulse might alter the effects of thyroid hormone.
Read the full Dulse Leaf Extract + Liotrix interactionIrish Moss ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, sea moss might alter the effects of thyroid hormone.
Read the full Irish Moss Extract + Liotrix interactionLiotrix, T4/t3Euthroid 2
How Liotrix, T4/t3 interacts with T-W — through 3 ingredients. Tap an ingredient for the detail:
Bladderwrack Algae ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Algae Extract + Liotrix, T4/t3 interactionDulse Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Theoretically, due to its iodine content, dulse might alter the effects of thyroid hormone.
Read the full Dulse Leaf Extract + Liotrix, T4/t3 interactionIrish Moss ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, sea moss might alter the effects of thyroid hormone.
Read the full Irish Moss Extract + Liotrix, T4/t3 interactionLithium Carbonate (prescription Drug)Eskalith, Lithium Carbonate
How Lithium Carbonate (prescription Drug) interacts with T-W — through 2 ingredients. Tap an ingredient for the detail:
Bladderwrack Algae ExtractLithium Moderate
Interaction Summary
Concomitant use of Fucus vesiculosus and lithium has resulted in hyperthyroidism.
Read the full Bladderwrack Algae Extract + Lithium Carbonate (prescription Drug) interactionWild Lettuce Aerial Parts ExtractCns Depressants Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Lithium Carbonate (prescription Drug) interactionLofepramineFeprapax, Gamanil, Lomont, Tymelyt
How Lofepramine interacts with T-W — through 2 ingredients. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractCns Depressants, Anticholinergic Drugs Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Lofepramine interactionBladderwrack Algae ExtractCytochrome P450 2d6 (cyp2d6) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
Read the full Bladderwrack Algae Extract + Lofepramine interactionLoperamideImodium, Loperamide
How Loperamide interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractAnticholinergic Drugs Moderate
Interaction Summary
Studies report varying evidence on whether or not wild lettuce contains hyoscyamine, an anticholinergic drug.
Read the full Wild Lettuce Aerial Parts Extract + Loperamide interactionLoperamide, SimethiconeImodium Advanced
How Loperamide, Simethicone interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractAnticholinergic Drugs Moderate
Interaction Summary
Studies report varying evidence on whether or not wild lettuce contains hyoscyamine, an anticholinergic drug.
Read the full Wild Lettuce Aerial Parts Extract + Loperamide, Simethicone interactionLorazepamAtivan
How Lorazepam interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractCns Depressants Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Lorazepam interactionLoxapineAdasuve, Loxitane
How Loxapine interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractAnticholinergic Drugs, Cns Depressants Moderate
Interaction Summary
Studies report varying evidence on whether or not wild lettuce contains hyoscyamine, an anticholinergic drug.
Read the full Wild Lettuce Aerial Parts Extract + Loxapine interactionMagnesium Sulfate (prescription Drug)Bilagog, Magnesium Sulfate
How Magnesium Sulfate (prescription Drug) interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractCns Depressants Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Magnesium Sulfate (prescription Drug) interactionMeclizineAntivert, Medivert, Ru-Vert M
How Meclizine interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractAnticholinergic Drugs Moderate
Interaction Summary
Studies report varying evidence on whether or not wild lettuce contains hyoscyamine, an anticholinergic drug.
Read the full Wild Lettuce Aerial Parts Extract + Meclizine interactionMenotropinsMenopur, Repronex
How Menotropins interacts with T-W — through 3 ingredients. Tap an ingredient for the detail:
Bladderwrack Algae ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Read the full Bladderwrack Algae Extract + Menotropins interactionDulse Leaf ExtractThyroid Hormone Moderate
Interaction Summary
Theoretically, due to its iodine content, dulse might alter the effects of thyroid hormone.
Read the full Dulse Leaf Extract + Menotropins interactionIrish Moss ExtractThyroid Hormone Moderate
Interaction Summary
Due to its iodine content, sea moss might alter the effects of thyroid hormone.
Read the full Irish Moss Extract + Menotropins interactionMeperidineCytospaz, Pethadol
How Meperidine interacts with T-W — through 2 ingredients. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractCns Depressants Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Meperidine interactionBladderwrack Algae ExtractCytochrome P450 2d6 (cyp2d6) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
Read the full Bladderwrack Algae Extract + Meperidine interactionMeperidine, PromethazineMepergan, Meprozine
How Meperidine, Promethazine interacts with T-W — through 2 ingredients. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractAnticholinergic Drugs, Cns Depressants Moderate
Interaction Summary
Studies report varying evidence on whether or not wild lettuce contains hyoscyamine, an anticholinergic drug.
Read the full Wild Lettuce Aerial Parts Extract + Meperidine, Promethazine interactionBladderwrack Algae ExtractCytochrome P450 2d6 (cyp2d6) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
Read the full Bladderwrack Algae Extract + Meperidine, Promethazine interactionMephenytoinMesantoin
How Mephenytoin interacts with T-W — through 2 ingredients. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractCns Depressants Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Mephenytoin interactionBladderwrack Algae ExtractCytochrome P450 2c9 (cyp2c9) Substrates Minor
Interaction Summary
Theoretically, concomitant use of Fucus vesiculosus with CYP2C9 substrates might increase the risk for adverse effects.
Read the full Bladderwrack Algae Extract + Mephenytoin interactionMephobarbitalMebaral
How Mephobarbital interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractCns Depressants Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Mephobarbital interactionMeprobamateEquanil, Meprospan, Miltown, Neuramate
How Meprobamate interacts with T-W — through 1 ingredient. Tap an ingredient for the detail:
Wild Lettuce Aerial Parts ExtractCns Depressants Moderate
Interaction Summary
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Read the full Wild Lettuce Aerial Parts Extract + Meprobamate interactionEach ingredient & the kinds of drugs it affects
For each ingredient in T-W with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.
Bladderwrack Algae Extract
Amiodarone (Cordarone)
Theoretically, combining Fucus vesiculosus with amiodarone might cause excessively high iodine levels.
Fucus vesiculosus contains high concentrations of iodine. Amiodarone contains 37.3% iodine and can increase iodine levels. Concomitant use might increase the risk of having excessive iodine levels and adversely affecting thyroid function. Monitor thyroid function.
Antithyroid Drugs
Due to its iodine content, Fucus vesiculosus might alter the effects of antithyroid drugs.
Fucus vesiculosus contains high concentrations of iodine. Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking Fucus vesiculosus while using antithyroid drugs could alter the effects of the antithyroid drugs.
Lithium
Concomitant use of Fucus vesiculosus and lithium has resulted in hyperthyroidism.
There is a case of hyperthyroidism occurring in a patient taking Fucus vesiculosus and lithium. Monitor thyroid hormones closely in patients taking lithium and Fucus vesiculosus concomitantly.
Thyroid Hormone
Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.
Fucus vesiculosus contains high concentrations of iodine. Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking Fucus vesiculosus while using thyroid hormone could alter the effects of thyroid hormone.
Anticoagulant/Antiplatelet Drugs
Theoretically, taking Fucus vesiculosus with antiplatelet or anticoagulant drugs might increase the risk of bruising and bleeding.
In vitro evidence suggests that a constituent of Fucus vesiculosus, known as fucoidan, has anticoagulant effects. However, in clinical research, fucoidan does not seem to have significant anticoagulant activity when taken orally, possibly due to poor absorption.
Cytochrome P450 2C8 (Cyp2C8) Substrates
Theoretically, concomitant use of Fucus vesiculosus with CYP2C8 substrates might increase the risk for adverse effects.
In vitro research shows that fucoidan, a constituent of Fucus vesiculosus, inhibits CYP2C8. This interaction has not been reported in humans.
Cytochrome P450 2C9 (Cyp2C9) Substrates
Theoretically, concomitant use of Fucus vesiculosus with CYP2C9 substrates might increase the risk for adverse effects.
In vitro research shows that fucoidan, a constituent of Fucus vesiculosus, inhibits CYP2C9. This interaction has not been reported in humans.
Cytochrome P450 2D6 (Cyp2D6) Substrates
Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.
In vitro research shows that fucoidan, a constituent of Fucus vesiculosus, both inhibits and induces CYP2D6. This interaction has not been reported in humans.
Cytochrome P450 3A4 (Cyp3A4) Substrates
Theoretically, concomitant use of Fucus vesiculosus with CYP3A4 substrates might increase the risk for adverse effects.
In vitro research shows that fucoidan, a constituent of Fucus vesiculosus, inhibits CYP3A4. This interaction has not been reported in humans.
Wild Lettuce aerial parts extract
Anticholinergic Drugs
Studies report varying evidence on whether or not wild lettuce contains hyoscyamine, an anticholinergic drug. If it does, it appears to be in very low amounts. Nevertheless, there have been case reports of individuals consuming large amounts of wild lettuce experiencing anticholinergic-related side effects, such as constipation, dry mouth, dizziness, and sweating. Therefore, if you are already taking a drug with anticholinergic effects, you should be cautious about combining it with wild lettuce as the risk of side effects may be increased.
Cns Depressants
Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.
Dulse Leaf Extract
Amiodarine (Cordarone)
Theoretically, combining dulse with amiodarone might cause excessively high iodine levels.
Dulse is rich in iodine, and amiodarone contains 37.3% iodine and can increase iodine levels.
Antithyroid Drugs
Theoretically, due to its iodine content, dulse might alter the effects of antithyroid drugs.
Dulse is rich in iodine. Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history.
Digoxin (Lanoxin)
Theoretically, dulse might increase the risk of hyperkalemia when taken with digoxin.
Dulse is rich in potassium, and digoxin can increase potassium levels in the blood. This interaction has not been demonstrated in humans.
Thyroid Hormone
Theoretically, due to its iodine content, dulse might alter the effects of thyroid hormone.
Dulse is rich in iodine. Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Although dulse has been associated with a statistically significant increase in thyroid stimulating hormone (TSH) levels in clinical research, clinically significant increases have not been documented.
Ace Inhibitors (Aceis)
Theoretically, dulse might increase the risk of hyperkalemia when taken with ACEIs.
Dulse is rich in potassium. ACEIs block the actions of the renin-angiotensin-aldosterone system and reduce potassium excretion. Concomitant use of these drugs with moderate dietary potassium intake (about 3775-5200 mg daily) does not increase serum potassium levels. However, using these drugs while consuming dulse in quantities that provide larger amounts of potassium daily might increase the risk of hyperkalemia. Additionally, in vitro research suggests that dulse protein hydrolysates inhibit the activity of ACE. However, these effects have not been demonstrated in humans.
Angiotensin Receptor Blockers (Arbs)
Theoretically, dulse might increase the risk of hyperkalemia when taken with ARBs.
Dulse is rich in potassium. ARBs block the actions of the renin-angiotensin-aldosterone system and reduce potassium excretion. Concomitant use of these drugs with moderate dietary potassium intake (about 3775-5200 mg daily) does not increase serum potassium levels. However, using these drugs while consuming dulse in quantities that provide higher amounts of potassium daily might increase the risk of hyperkalemia. Additionally, in vitro research suggests that dulse protein hydrolysates inhibit the activity of angiotensin converting enzyme (ACE). However, these effects have not been demonstrated in humans.
Potassium-Sparing Diuretics
Theoretically, dulse might increase the risk of hyperkalemia when taken with potassium-sparing diuretics.
Dulse is rich in potassium, and potassium-sparing diuretics can increase potassium levels in the blood. This interaction has not been shown in humans.
Irish Moss Extract
Amiodarone (Cordarone)
Theoretically, combining sea moss with amiodarone might cause excessively high iodine levels.
Amiodarone contains 37.3% iodine and can increase iodine levels. Concomitant use with sea moss, which contains approximately 4-7 mcg of iodine per gram, might increase the risk of adverse effects from iodine, including altered thyroid function.
Antithyroid Drugs
Due to its iodine content, sea moss might alter the effects of antithyroid drugs.
Sea moss contains approximately 4-7 mcg of iodine per gram. Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking sea moss could theoretically alter the effects of antithyroid drugs.
Thyroid Hormone
Due to its iodine content, sea moss might alter the effects of thyroid hormone.
Sea moss contains approximately 4-7 mcg of iodine per gram. Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking sea moss could theoretically alter the effects of thyroid hormone.
Brand information
Manufacturer and brand details for T-W, from the product label.
Pure Herbs
See all Pure Herbs products- Name
- Pure Herbs, Ltd.
- City
- Sterling Heights
- State
- MI
- Phone Number
- (800) 860-4372
- Web Address
- www.pureherbs.com
T-W by Pure Herbs: Common Questions
Does T-W by Pure Herbs interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Can I take this if I'm pregnant or breastfeeding?
Is sea moss (Irish moss) the same as the other seaweeds in this product?
What is wild lettuce and what is it supposed to do?
Why are there so many medication interactions listed?
Are there any side effects I should watch for?
Can this product help with iodine deficiency?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.
The Full Monographs Behind T-W’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Fucus Vesiculosus
Interacts with 891 drugsFucus vesiculosus (bladderwrack) is a brown seaweed rich in iodine that has been used traditionally for thyroid concerns, weight, and skin. There is little solid human evidence to support mo...
Read the full Fucus Vesiculosus monograph → Herb & supplement monographSea Moss
Interacts with 22 drugsSea 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 i...
Read the full Sea Moss monograph → Herb & supplement monographDulse
Interacts with 85 drugsDulse is a red seaweed eaten as a food in many coastal cultures and is a natural source of iodine, potassium, protein, and antioxidant compounds. As a food it is generally considered safe fo...
Read the full Dulse monograph → Herb & supplement monographWild Lettuce
Interacts with 393 drugsWild lettuce is a traditional herb used mainly for sleep, anxiety, and pain, but solid human research supporting these uses is very limited. Because its safety is not well studied, it should...
Read the full Wild Lettuce monograph →Sources & How We Checked
T-W's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.
- NIH Dietary Supplement Label Database (DSLD) — The official product label on file for this supplement.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference behind the ingredient interaction data.
Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.
The 28 references behind this product’s interaction data
Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.
Fucus Vesiculosus 15 references
- Goodman GA, Rall TW, Nies AS, Taylor P. The Pharmacological Basis of Therapeutics, 9th ed.
- Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
- Phaneuf D, Cote I, Dumas P, et al. Evaluation of the contamination of marine algae (Seaweed) from the St. Lawrence River and likely to be consumed by humans. Environ Res 1999;80:S175-S182. PubMed
- Durig J, Bruhn T, Zurborn KH, et al. Anticoagulant fucoidan fractions from Fucus vesiculosus induce platelet activation in vitro. Thromb Res 1997;85:479-91. PubMed
- Conz PA, La Greca G, Benedetti P, et al. Fucus vesiculosus: a nephrotoxic alga? Nephrol Dial Transplant 1998;13:526-7.
- Ohye H, Fukata S, Kanoh M, et al. Thyrotoxicosis caused by weight-reducing herbal medicines. Arch Intern Med 2005;165:831-4. PubMed
- Okamura K, Inoue K, Omae T. A case of Hashimoto's thyroiditis with thyroid immunological abnormality manifested after habitual ingestion of seaweed. Acta Endocrinol (Copenh) 1978;88:703-12. PubMed
- Agarwal SC, Crook JR, Pepper CB. Herbal remedies -- how safe are they? A case report of polymorphic ventricular tachycardia/ventricular fibrillation induced by herbal medication used for obesity. Int J Cardiol 2006;106:260-1. PubMed
- Sterling JB, Heymann WR. Potassium iodide in dermatology: a 19th century drug for the 21st century-uses, pharmacology, adverse effects, and contraindications. J Am Acad Dermatol 2000;43:691-7. PubMed
- Catania, M. A., Oteri, A., Caiello, P., Russo, A., Salvo, F., Giustini, E. S., Caputi, A. P., and Polimeni, G. Hemorrhagic cystitis induced by an herbal mixture. South.Med.J. 2010;103(1):90-92. PubMed
- Cumashi, A., Ushakova, N. A., Preobrazhenskaya, M. E., D'Incecco, A., Piccoli, A., Totani, L., Tinari, N., Morozevich, G. E., Berman, A. E., Bilan, M. I., Usov, A. I., Ustyuzhanina, N. E., Grachev, A. A., Sanderson, C. J., Kelly, M., Rabinovich, G. A., I
- Irhimeh, M. R., Fitton, J. H., and Lowenthal, R. M. Pilot clinical study to evaluate the anticoagulant activity of fucoidan. Blood Coagul.Fibrinolysis 2009;20(7):607-610. PubMed
- Arbaizar, B. and Llorca, J. [Fucus vesiculosus induced hyperthyroidism in a patient undergoing concomitant treatment with lithium]. Actas Esp.Psiquiatr. 2011;39(6):401-403.
- Church FC, Meade JB, Treanor RE, and et al. Antithrombin activity of fucoidan. The interaction of fucoidan with heparin cofactor II, antithrombin III, and thrombin. J Biol Chem 2-25-1989;264(6):3618-3623. DOI
- Mathew L, Burney M, Gaikwad A, et al. Preclinical evaluation of safety of fucoidan extracts from Undaria pinnatifida and Fucus vesiculosus for use in cancer treatment. Integr Cancer Ther 2017;16(4):572-84.
Sea Moss 3 references
- 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
- 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.
- 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
Dulse 5 references
- Malta D, Arcand J, Ravindran A, Floras V, Allard JP, Newton GE. Adequate intake of potassium does not cause hyperkalemia in hypertensive individuals taking medications that antagonize the renin angiotensin aldosterone system. Am J Clin Nutr 2016 Oct;104(4 PubMed
- Allsopp P, Crowe W, Bahar B, et al. The effect of consuming Palmaria palmata-enriched bread on inflammatory markers, antioxidant status, lipid profile and thyroid function in a randomised placebo-controlled intervention trial in healthy adults. Eur J Nutr PubMed
- McGrath BM, Harmon JP, Bishop G. Palmaria palmata (Dulse) as an unusual maritime aetiology of hyperkalemia in a patient with chronic renal failure: a case report. J Med Case Rep. 2010;4:301. PubMed
- Furuta T, Miyabe Y, Yasui H, Kinoshita Y, Kishimura H. Angiotensin I converting enzyme inhibitory peptides derived from phycobiliproteins of dulse Palmaria palmata. Mar Drugs. 2016;14(2):32. PubMed
- Takase T, Nakamura A, Miyoshi H, et al. Effects of Palmaria palmata on lipid metabolism and glycemic control in participants with hypercholesterolemia in a randomized double-blind placebo-controlled trial. Phytother Res. 2020.
Wild Lettuce 5 references
- Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
- Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
- Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
- Besharat S, Besharat M, Jabbari A. Wild lettuce (Lactuca virosa) toxicity. BMJ Case Rep. 2009;2009. pii: bcr06.2008.0134.
- Mullins ME, Horowitz BZ. The case of the salad shooters: intravenous injection of wild lettuce extract. Vet Hum Toxicol. 1998;40(5):290-1.
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