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Sea Moss Complex - Pure Irish Sea Moss Capsules with Bladderwrack & KSM Ashwagandha - High Strength Seamoss Capsule - 120 Fill Vegan Irish Seamoss Capsules Made in The UK By New Leaf
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Sea Moss Complex - Pure Irish Sea Moss Capsules with Bladderwrack & KSM Ashwagandha - High Strength Seamoss Capsule - 120 Fill Vegan Irish Seamoss Capsules Made in The UK By New Leaf

★4.4 / 5 ★★★★☆ on Amazon · 283 customer ratings · recorded 27 Jul 2026
3.3/5
BasketLab score Our own assessment, not the Amazon rating · how we score
  • Evidence3.0
  • Value4.0
  • Suitability2.5
  • Transparency3.5

An inexpensive, well-rated version of a popular supplement, with a standardised KSM-66 extract rather than a vague one. Suitability scores low because the iodine content makes it genuinely unsuitable for several groups, and the human evidence behind the claims is thin.

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Live Amazon price · product details checked 5 September 2026

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Overview

Sea moss went from obscure seaweed to social-media staple in a couple of years, and the claims made for it online run far ahead of the evidence. This New Leaf complex pairs Irish sea moss with bladderwrack and KSM-66 ashwagandha at around £9, with a 4.4 rating from roughly 270 buyers. Here is a level-headed look at what is in it and what you can reasonably expect.

At a glance
Contains
Irish sea moss, bladderwrack, KSM-66 ashwagandha
What it is
Nutrient-dense seaweed, naturally high in iodine
Rating
4.4 / 5 from ~273 reviews
Typical price
Around £9 (check live price below)
Important
High iodine; thyroid conditions need medical advice first
Honest note
Popular online; robust human evidence is limited

What sea moss and bladderwrack actually are

Sea moss (Chondrus crispus, or Irish moss) is a red seaweed traditionally harvested around the Atlantic coasts and long used in Irish and Caribbean cooking as a thickener and folk remedy. Bladderwrack is a brown seaweed from the same cool waters. Both are genuinely nutrient dense, containing a range of minerals, and both are <strong>naturally rich in iodine</strong>.

That iodine content is the single most important practical fact about this category, and it is usually buried in the marketing. Iodine matters for normal thyroid function, but the range between too little and too much is narrower than most people assume.

The honest position on the claims

Sea moss is credited online with everything from weight loss to immunity to skin transformation. The reality is that <strong>robust human trials are limited</strong>, and most of what circulates is extrapolated from nutrient content or traditional use rather than clinical evidence. As a food supplement it cannot be said to treat, prevent or cure anything, and UK advertising rules are strict on that.

What can be said fairly: it is a mineral-rich seaweed, it supplies iodine, and plenty of people take it daily and feel it suits them. That is a reasonable basis for trying it, and a poor basis for expecting a transformation.

KSM-66 ashwagandha: the addition worth knowing about

KSM-66 is a branded, standardised ashwagandha extract, and it is a more meaningful inclusion than a generic 'ashwagandha' listing because standardisation means a defined amount of active compounds. Ashwagandha is an adaptogen traditionally used around stress and sleep.

It also changes who should be careful: ashwagandha is generally advised against in pregnancy, and can interact with thyroid medication and sedatives. Combined with the iodine question, that makes this a supplement worth a quick conversation with a pharmacist if you take anything regularly.

Is it worth trying? Our verdict

At around £9 it is an inexpensive way to try a well-rated version of a popular supplement, with a sensible standardised ashwagandha rather than an unspecified one. If you are curious and healthy, the outlay is small.

Our score is held back for one reason: the gap between how confidently sea moss is marketed and how thin the human evidence actually is. And a genuine caution rather than a formality: <strong>if you have any thyroid condition, take thyroid medication, or are pregnant, speak to your GP or pharmacist before taking iodine-rich seaweed supplements</strong>. This is the category where that advice is least optional.

Key features, as the manufacturer lists them

Taken from the product listing via Amazon's product API. These are the seller's claims, not our test results.

Frequently asked questions

What does sea moss do?

It is a mineral-rich red seaweed that supplies iodine among other nutrients. Beyond that, robust human evidence is limited, and the claims circulating online run well ahead of what has been demonstrated. As a food supplement it cannot be said to treat or prevent any condition.

Is sea moss safe for thyroid problems?

Speak to your GP first. Sea moss and bladderwrack are naturally high in iodine, and both too little and too much iodine can affect thyroid function. Anyone with a thyroid condition or taking thyroid medication should get medical advice before starting.

What is bladderwrack for?

Bladderwrack is a brown seaweed included alongside sea moss for its mineral content, and it is also a significant iodine source. It is traditional rather than clinically established, and the same iodine caution applies.

What is KSM-66 ashwagandha?

KSM-66 is a branded, standardised ashwagandha extract, meaning a defined amount of active compounds rather than an unspecified powder. Ashwagandha is an adaptogen traditionally used around stress and sleep, and is generally not advised in pregnancy or alongside certain medications.

Who should avoid sea moss supplements?

Anyone pregnant or breastfeeding, anyone with a thyroid condition or on thyroid medication, and anyone taking sedatives or medication that could interact with ashwagandha should check with a GP or pharmacist first.

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