Seagreens® Information Service  0845-0640040 / +44-1444-400403

Practitioners listed in our database are likely to have a good understanding of Seagreens nutrition products and their uses.

Please click here to search the list and if you would like to discuss any matter with Seagreens please contact Seagreens Information Service.


These orgnisations may be able to help you locate a qualified nutritional therapist or related clinic, or provide training to become a practitioner.
Click at the top of the page for our list of qualified practitioners who are familiar with the application and use of Seagreens® nutrition products.

CNM College of Naturopathic Medicine - colleges throughout the UK and overseas
1 Bullrushes Farm, Coombe Hill Road, East Grinstead, West Sussex RH19 4LZ
+44 (0)1342 410505

NNA Naturopathic Nutrition Association
2 Uffcott Farm, Uffcott, Wiltshire SN4 9MB
01908 616543

BANT British Association for Nutrition and Lifestyle Medicine
27 Old Gloucester Street, London WC1N 3XX
01425 462532

Practitioners trained in the GAPS diet can be found via the GAPS Training website.

Please click here for an introductory video by Dr Natasha Campbell-McBride.

Seagreens® nutrition research, published papers and other articles are available here.
To learn more about its evidence-based applications and the native wild seaweeds we produce, click here.

Why Consider Seaweed for Women's Health Concerns?

by Jane Jamieson PhD, Nutritional therapist, Edinburgh
(this edited article first published June 2023 online in Positive Health)

Seaweed, or sea vegetables as they are sometimes called, are a rich source of whole-food nutrition. If they are harvested correctly from pollution-free waters they can be a welcome addition to anybody's diet (Cherry et al., 2019). They have a special place in women's health and it is likely that they were a traditional source of nutrition which supported fertility around the world. Seaweed is used extensively in other island nations such as Japan and the Philippines, and in Korea and China.

One of the comprehensive minerals in seaweed, crucial for women's health, is iodine. Many people are aware of the importance of iodine for thyroid health. The thyroid hormones 3T and 4T are aptly named for the number of iodine atoms they contain. T3 contains three iodine atoms and T4 contains four. Good thyroid health is important for fertility, and there are other reasons why iodine is important for women's health.

Iodine is used as an antiseptic (Sibbald, Leaper and Queen, 2010). It is needed in the body to protect breast tissue from infection from bacteria, viruses and fungi. The milk ducts in the breast are an external opening and can allow bacteria and viruses into the breast. Higher iodine levels have been shown to protect the breast from breast cancer (Cotas et al., 2021), and there is a link between certain viruses causing certain cancers, so iodine may also protecting the breast in this way.

Seaweed has other benefits, too. Many of the challenges associated with women's health concerns such as dysmenorrhea, endometriosis, POS , infertility, menopause and breast cancer, can be related to imbalances in the hormones: oestrogen and progesterone.

This balance is affected by the clearance of these hormones, especially oestrogen. Oestrogens are metabolised by the liver and conjugated to functional groups (amino acids, sulphur, methyl groups for example) which aid its elimination, then they are excreted through the bile to the stool and eliminated from the body.

The challenge to hormone balance comes when the oestrogens are not cleared thoroughly from the body, which leads to oestrogen dominance. This dominance is partly due to the excess amounts of oestrogen and partly the fact that the oestrogens change their function and become more potent after they have been metabolised by the liver.

Oestrogen needs to be cleared from the body by binding to soluble fibre. In addition, oestrogen clearance is also affected by the bacteria in the digestive system. Certain bacteria can uncouple or deconjugate oestrogen from the functional groups, which then allows oestrogens to be more readily re-absorbed back into the bloodstream.

The key interventions that support oestrogen clearance are sufficient soluble fibre to bind to oestrogen to enable its elimination, and a healthy microbiome in the gut which will cause the deconjugation of oestrogen.

Several studies show the beneficial effect of seaweed polysaccharides (soluble fibre) on the gut microbiome and not surprisingly there is a corresponding positive effect of seaweed on changes in hormone balance too.

A particular seaweed species (Fucus vesiculosus, Bladder wrack) has been shown to reduce the oestrogenic hormones and boost progesterone levels, bringing reproductive hormones into better balance. In a pilot study, a few women had abnormally short menstrual cycles. 0.7-1.4g of seaweed normalised their menstrual cycle in a dose dependant manner, showing that oestrogen levels were altered in a favourable way by the addition of seaweed in post-menopausal women. It was thought likely that this was due to beneficial changes to the gut microbiome (Skibola et al., 2004, and Teas et al., 2009).

Many seaweeds have been shown to reduce inflammation in the body through several mechanisms: by inhibiting reactive oxygen species, and by regulating inflammation through reducing pro-inflammatory NF-kB signalling and by interfering with T-helper cell polarisation (Olsthoorn et al.. 2021). Improving inflammatory status is a positive attribute in endometriosis.

Seaweeds and microalgae contain the full range of nutrients needed to sustain the marine ecosystem and both macro- and micro-algae are classed as the primary producers within this ecosystem. The nutrient profile of seaweeds is very rich and includes protein, omega-3 fatty acids, unusual polysaccharides, soluble fibre, vitamins, minerals, antioxidants and other phyto-chemicals which allow seaweed to adapt to its harsh and changing environment (Hentati et al., 2020).

Understandably, given the unique properties of some of the polysaccharides and antioxidants in seaweed, there is growing interest in the use of seaweed as therapeutic agents. This brings a trend towards extracting elements of the seaweed as they may yield different pharmaceutical agents (Cherry et al., 2019; Cotas et al., 2021).

Whilst this might produce some interesting new medications, it risks losing sight of the fact that intact and whole seaweeds offer a broad range of nutrition, likely to stimulate and satisfy the body in ways that extracts which have been separated out, processed and refined, cannot.

It is after all, the consumption of whole-food seaweed by people such as the Japanese, that has led us to understand the health benefits of these interesting plants (Cherry et al., 2019; Teas et al., 2013). We must be careful that we do not throw the proverbial baby out with the bathwater.

How should seaweed be used therapeutically? What seaweeds should be considered and how should these seaweeds be used? Another pertinent question is, are there any safety concerns? The safety issues around seaweed relate particularly to its allergenic potential, contamination by heavy metals and other natural and man-made contaminants, and its iodine concentration.

Rare allergic reactions to certain seaweeds are known, such as to Nori (Pyropia species), but less is known about European species. Allergies to cross-contaminated molluscs, shellfish or fish are more likely, and seaweed products normally warn against these allergens.

Anyone who develops allergic symptoms should stop their seaweed consumption. It is possible to test by making the dried seaweed into a paste with water and placing this directly on the skin. Leave the damp paste on the skin for twenty four hours with a dressing over it, to see if the skin reacts. Reaction is very uncommon, for example in the case of one pilot study of 81 participants, only one person developed a rash after consuming seaweed (Sterling and Butler, 2021).

Contamination by heavy metals can be a particular issue if seaweed has been harvested in polluted waters (Cherry et al., 2019; Lomartive et al., 2021). Choosing a responsible seaweed producer who tests their product for all forms of likely marine contamination would address this issue.

One British producer of our native wild seaweeds exclusively for human nutrition, does test every production batch for all forms of contamination and their seaweed is certified non-allergenic. Seagreens® produces a small range of its own nutrition products, and supplies companies like Clearspring, Cytoplan, G&G vitamins, Pukka, Viridian Nutrition and Wise Owl Health among others in the UK and overseas.

International food safety regulations only partially address these issues around seaweed, and there are calls for wider regulation so that the public are able to be confident in any seaweed they might be consuming (Circuncisão et al. 2018).

Seagreens Trust's Seaweed Health Foundation developed the Nutritious Food Seaweed production standard in 2016, which does address these issues, but it has yet to be taken up on any larger scale. It is certified by the UK Biodynamic Association, and is the first food standard to require transparency for consumers of a minimum nutritional profile and the overall composition of the certified seaweed.

Again, only Seagreens guarantees the parameters of the iodine levels in its seaweeds. Different species tested for iodine levels show a range of iodine concentration from 0.004 to 2.66g/kg (Hentati et al., 2020) and products should clearly indicate the levels of iodine in their product.

Choose a seaweed with higher levels of iodine only where there is a known deficiency, but research indicates that only some 30% of the iodine content is likely to be absorbed in the body. Excess iodine is also readily excreted.  Whilst the 'recommended' daily requirement for adults is in the region of 250 micrograms per day, and half that for children, more than 60% of women in the UK are iodine-deficient (Combet et al., 2014). The fact is that most people need more rather than less.

The question of which kind of seaweed to choose is not an exact science as there is not enough research on each individual seaweed for all health complaints. Research into seaweed is showing a wide profile of nutrition for all seaweeds, brown seaweed species generally having a greater concentration and range of minerals and antioxidants, and the red seaweeds having a higher proportion of polysaccharides (Begum et al., 2021; Circuncisão et al. 2018).

Consuming seaweeds known for their nutritional profile, which can be shown to support general health, reduce oxidative stress, support the microbiome and improve hormonal balance is an effective strategy, and the brown Wrack species Ascophyllum nodosum, and Fucus vesiculosus amongst others, certainly fall into this category (Begum et al., 2021; Circuncisão et al. 2018).

The therapeutic amount of seaweed often used in literature can range from 0.7-5g of seaweed (Cherry et al., 2019; Skibola, 2014; Teas et al., 2013). In Asian countries a daily intake of 4-7g of seaweed is consumed by regular seaweed eaters (Cotas et al. 2021). The breakdown by type of these seaweeds used is not discussed, however.

Nori, very widely used for sushi in Japanese cuisine, has one of the lowest levels of iodione, so it is unwise to translate 4-7q directly into Western diets using native wild seaweeds available in the UK, although some native species like Pelvetia (Channel Wrack) and Palmaria (Dulse) also contain comparatively low amounts of iodine.

Seaweed has been shown to function in a dose-dependant manner and therefore, using the higher doses for a period of time may be recommended, although caution is urged, as once the dose gets too high, seaweed consumption can cause problems for human health (Cotas et al, 2021).

Given the fact that seaweed modifies the microbiome and supports detoxification, it makes sense to start gently with seaweed and build up to a therapeutic dose (4-5g), based on your knowledge of its nutritional profile. Among practitioners who have worked extensively with Seagreens, it is accepted wisdom that a therapeutic dose might be sustained for several weeks or 1-2 months and then the dose could de tapered down to a maintenance dose (1-2g a day).

Many researchers caution using high doses of seaweed (5 grams or more) for an extended period of time. Small amounts of seaweed (1 gram) used every day may be of benefit by consistently filling nutritional deficits rather than large doses used more infrequently. The body appreciates a steady balance of good quality nutrition.

Do monitor the symptoms of your clients to see what works best for them. Some people will do well on comparatively low dose of seaweed as therapeutic, while others will need to sustain a higher level of daily use for prolonged periods of time. This is where clinical judgement is important, and testing nutrient levels like iodine can also play a part.


• Begum et al., 2021. Antioxidant and Signal-Modulating Effects of Brown Seaweed-Derived Compounds against Oxidative Stress-Associated Patholoay, Oxidative Medicine and Cellular Longevity.

• Cherry et al., 2019. Risks and benefits of consuming edible seaweeds, Nutrition Reviews, 77, 5, 307-329.

• Circuncisão et al. 2018. Minerals from macroalgae origin: Health benefits and risks for consumers, Marine Drugs, 16, 1.

• Cotas et al., 2021. Seaweeds' nutraceutical and biomedical potential ni cancer therapy: A concise review, Journal of Cancer Metastasis and Treatment, 7.

• Hentati et al., 2020. Bioactive polysaccharidesfrom seaweeds, Molecules, 25, 14.

• Lomartive et al.. 2021. An overview to the health benefits of seaweeds consumption, Marine Drugs, 19, 6.

• Olsthoorn et al., 2021. Brown seaweed food supplementation: Effects on allergy and inflammation and its consequences, Nutrients, 13, 8.

• Sibbald, Leaper and Queen, 2010. Iodine Made Easy, Wounds International, 2, 2, s1-56.

• Skibola, 2004. The effect of Fucus vesiculosus, an edible brown seaweed, upon menstrual cycle length and hormonal status in threp pre-menopausal women: A case report. BMC Complementary and Alternative Medicine, 4.

• Sterling and Butler, 2021. The Attenuation of Dysmenorrhea and Menorrhagia by the Red Seaweed Kappaphycus alvarezi: A Pilot Study. 2021.

• Teas et al.. 2009. The consumption of seaweed as a protective factor in the etiology of breast cancer: Proof of principle, Journal of Applied Phycology, 25, 3, 771-779.

• Teas et al., 2013. Dietary seaweed modifies estrogen and phytoestrogen metabolism in healthy postmenopausa women, Journal of Nutrition, 139, 5, 935-944.

Thyroid Health
Jules Chandler Dip CNM, mBANT, CHNC, MTI Nutritional Therapist - Bristol central, Keynsham, and Knowle.
Jules is a registered Nutritional Therapist providing evidence-based nutritional therapy with a naturopathic, person-centred approach.
She is a member of BANT, CHNC, MTI, The World Health Heroes and is a Clinical Supervisor at The College of Naturopathic Medicine. Jules facilitates free monthly thyroid support groups and holds quarterly talks on ‘all things thyroid’. Appointments and enquiries Tel 07921 617623. Click here for the website.

So…what is a thyroid condition? 
Thyroid dysfunction, in my humble opinion, is the most undertreated condition in the UK at this time. Hypothyroid (underactive), hyperthyroid (overactive), Hashimoto’s (autoimmune), Graves’s Disease (overactive), toxic nodules, viral thyrotoxicosis, postpartum thyroid, the list of thyroid diseases is endless, but the symptoms are similar with most types, whatever the causation.

Symptoms will manifest in the body either metabolising too quickly or too slowly. An underactive client will typically present with weight gain, constipation, tiredness and hair loss and the doctors seem to be at a loss when symptoms other than this present in clinic; e.g. there are slim underactive thyroiders, there are overweight overactive thyroiders and vice versa. There are thyroid clients who can function mentally extremely well and there are others existing in a constant battle sea of brain fog or debilitating anxiety. For some, muscle pain is an issue, whilst for others, there is not even a hint of post-exercise malaise or lack of recovery. 

What is the thyroid? 
If the body is the orchestra then the thyroid is definitely the conductor, keeping pace and noting when things need to slow down or pick up speed. Thyroid hormones control many of our major cellular metabolic processes via the synthesis, storage and release of thyroid hormones (T4, T3, T2, T1, T0 and calcitonin). Is it any wonder that when we see a thyroid client who is struggling, the symptoms lay within all of the systems; brain fog, muscle pain or weakness, constipation, fatigue, the list is endless.

The synthesis of a thyroid hormone begins when the hypothalamus responds to sensory input from the environment (e.g. the modern tiger aka 6012 emails!). The pituitary gland is prompted to release thyroid stimulating hormone (TSH) in order to synthesise thyroxine in the thyroid gland. Then, the biochemical magic really begins…. Wiith the help of thyroid peroxidase enzyme (TPO), tyrosine is joined by an iodine atom, creating a compound, known as monoiodotyrosine (MIT). It continues to add further iodine atoms together until reaching four in total thus becoming thyroxine (also known as T4!).

The thyroid gland will release 80% as t4, 16% as t3 and the remainder as t2 and t1 hormones (Peatfield, 2006). T4 is a storage hormone travelling on its merry little way via the bloodstream to peripheral conversion sites, mainly in the liver, where an iodine atom is cleaved by a selenoenzyme to become T3 (triiodotyrosine). T3, the true hormone, four times more potent than T4, then enters every cell in the body enabling every wonderful metabolic process that most of us take for granted. 

Where does it all go wrong? 
I see more autoimmune cases than anything else in clinic. A classic case of gut permeability and the immune system going totally haywire, at (Campbell, 2014) tacking the TPO or TSI receptors and creating havoc. Add a ton of stress as a driver, a predisposition to autoimmunity and some foods that give our client little nutrient density and it’s a recipe for disaster. (Vanderpump, M 2011).

There is much success in implementing the 4R protocol and I have seen astonishing results where antibodies hit the floor after just a few months with gut healing work. This simple protocol involves a four-stage gut healing process; REMOVE foods, pathogens, bacteria or parasites that may be damaging the gut, REPLACE any digestive components that may be missing; stomach acid, digestive enzymes, REPOPULATE with probiotics and REPAIR with specific supplements and foods to rebuild intestinal lining. (Rapin, Wiernsperger, 2010).

Another common puzzle is when client’s labs present with a high T4 and low T3 - a suggestion that there is a lack of conversion between T4 and T3. Many times, there is an oestrogen or cortisol dominance, preventing the T3 reaching the cell receptors. Lifestyle management and stress reduction can help hugely and often there is insufficient nutrient density and a lack of nutrient co-factors to achieve conversion so its back again to the classic 4R. A polymorphism of the D102 gene may be a factor, disabling the client’s ability to convert Levothyroxine to T3 resulting in a high T4 and low T3 (Wartofsky L, 2013). 

Reverse T3 can be an issue for some people with extreme stress. The body will not accept and convert T4 so easily in times of challenge and in this case, the T4 will convert to reverse T3 thus showing classic hypothyroid symptoms with euthyroid lab work.

Then, there are those without a thyroid, like myself. Clients who have had Graves’s disease and a total thyroidectomy, atrophied thyroids; reliant on levothyroxine, the 1960’s one-size-fits-all wonder drug meant to replace endogenous T4. For many people, it works and others have had to find ways around it. Get the permeable gut tight, efficient, ‘ship shape and Bristol fashion’ as we say here in the South West! Reducing any stress load is next, hyped adrenals are not good with a dysfunctional thyroid function. They are best buddies and bounce off each other, altruistically helping each other out in times of need yet compromising and damaging themselves in the process. Adrenal recovery is key here (Seck-Gassama, 2000) alongside optimisation of conversion of the synthetic T4 to T3 with selenium and zinc.

If you still have a thyroid, I believe you’re in with more of a chance, encouraging it to make its own endogenous thyroxine again. Making sure the gut is tight is still number one on the list as nutrient density is essential, particularly tyrosine (Palinkas, Reedy, Smith, 2007). The most bioavailable source comes from fermented kefir milk. Phenylalanine is useful as a pre-cursor to tyrosine and can be found in avocado, banana, brown rice, cheese, eggs, lentils, meat, nuts, fish and soy beans. 

Controversially, iodine is number two on the list. If a client is deficient in this, they will not produce enough T4 or T3 (Hye Rim Chung, 2014). When there isn’t enough iodine in the body, the thyroid will swell in order to trap any spare iodine floating about the place resulting in a goitre. This does not mean that each goitre is due to there not being enough iodine. Remember there are lots of reasons why a thyroid creates havoc. Placing an iodine supplement into your client’s eager hands is not always the 
best idea.

It needs to be done in a certain way; too much or the wrong type of iodine can create just as much havoc as too little. Food sources should still be moderated and can include seafood, sea salt and sea vegetables. 

The UK NHS range for the TSH (thyroid stimulating hormone) testing is extremely broad (0.4-4.6). Many clients present as euthyroid with bloodwork presenting as 4.6 and there is no further NHS testing of T4 or T3 unless the TSH is out of range. Therefore, private testing is easily available and thoroughly encouraged. I hope this article has helped a little with the complexity of thyroid conditions and that you have come to believe that whatever a client’s symptoms, a thyroid disease is rarely a diseased thyroid. 

• Campbell, (2014) ‘Autoimmunity and the Gut’, Dis. 2014; 2014: 152428. Published online 2014 May 13. doi: 10.1155/2014/152428, PMCID: PMC4036413, The Wellness Center, 23144 Emerson Way, Land O Lakes, FL 34639, USA. Available at:
• Hye Rim Chung, (2014) ‘Iodine and Thyroid Function’. Ann Pediatr Endocrinol Metab. 2014 Mar; 19(1): 8–12. Published online 2014 Mar 31. doi: 10.6065/apem.2014.19.1.8 PMCID: PMC4049553 PMID: 24926457. Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea. Address for correspondence: Hye Rim Chung, MD. Department of Pediatrics, Seoul National University Bundang Hospital, 82 Gumi-ro 173 beon-gil, Bundang-gu, Seongnam 463-707, Korea. Tel: +82-31-787-7292, Fax: +82-31-787-4054. Available at: 
• Palinkas LA1, Reedy KR, Smith M, (2007) ‘Psychoneuroendocrine effects of combined thyroxine and triiodothyronine versus tyrosine during prolonged Antarctic residence.’ International Journal of Circumpolar Health, 66(5):401-17. Available at: 
• Peatfield (2006) Your Thyroid and How to Keep it Healthy: The Great Thyroid Scandal and How to Survive It, 2nd Edition, London, Hammersmith Press Limited. 
• Rapin, Wiernsperger (2010) ‘Possible Links between Intestinal Permeablity and Food Processing: A Potential Therapeutic Niche for Glutamine’ Clinics (Sao Paulo). 2010 Jun; 65(6): 635–643, doi: 10.1590/S1807-59322010000600012, PMCID: PMC2898551. Available at: 
• Seck-Gassama, (2000) ‘Serum cortisol level variations in thyroid diseases’. Dakar Med 2000;45(1):30-3, Seck-Gassama, Ndoye O, Mbodj M, Akala A, Cisse F, Niang M, Ndoye R. Laboratoire de Biophysique et Médecine Nucléaire-Faculté de Médecine-Université Cheikh Anta Diop de Dakar-Sénégal. 
• Vanderpump, M (2011), ‘The epidemiology of thyroid disease’. Oxford Journals, Medicine & Health , British Medical Bulletin, Volume 99, Issue 1, Pp. 39-51, Department of Endocrinology, Royal Free Hampstead NHS Trust, Pond Street, London NW3 2QG, UK. Available at: 
• Wartofsky L (2013), ‘Combination L-T3 and L-T4 therapy for hypothyroidism’. Current Opinion in Endocrinology, Diabetes and Obesity. Oct;20(5):460-6. doi: 10.1097/ Department of Medicine, Washington Hospital Center, Georgetown University, Washington, District of Columbia, USA. Available at: 

Seagreens®: Independent research demonstrates superior performance of Seagreens iodine in nutrition
Independent research at Glasgow University, published in the British Journal of Nutrition (2014) addressed the different behaviour of Seagreens Ascophyllum (~700mg/kg iodine) in the body compared to potassium iodide, a widely used iodine supplement. The study found that potassium iodide is highly bioavailable and quickly excreted, whereas the Seagreens Ascophyllum is less bioavailable and remains in the body for longer, being excreted in higher amounts from the body over a prolonged period. The body uses what it needs and gets rid of the rest. Approximately 33% of the natural seaweed iodone was absorbed in iodine deficient female trial subjects achieving iodine sufficiency with no adverse effect on the thyroid. Click here for more about Seagreens nutrition research.
Combet et al., 2014. Low level seaweed supplementation improves iodine status in iodine-insufficient women. British Journal of Nutrition. View or download this paper.

View or download Seagreens® booklet 'Iodine sufficiency from nutritious food seaweed'