What Is Ideal Dosage of Kelp Supplements

Kelp grows underwater and is often mistaken for seaweed.

However, this majestic plant which sometimes grows to great heights, belongs to a different plant species – brown algae. The whole kelp plant is sun dried, granulated and used to make kelp supplements, liquid, powders etc.

It can be added to many recipes and is often used as a salt substitute.

Take care to purchase kelp from protected and safe waters, usually found off the coasts of Hawaii, Iceland, Norway, North West United States and Canada.

Kelp Supplements

Many nutritionists suggest using the right kelp supplement as a life-saving addition to our diets.

The right brand is safe and provides excellent benefits. Some brands of kelp supplements like ‘Monterrey Bay Herb Company’ and ‘Frontier Herbs’ have kelp granules which are non-toxic and contain high levels of alginate.

Kelp supplements provide an excellent source of minerals like zinc, calcium, iron, manganese, copper, chromium, magnesium and sodium.

It also contains trace minerals like iridium, germanium and rubidium. Most of modern day foods are sadly insufficient in such minerals. Hence, taking kelp supplements can provide all the required minerals easily.

Kelp supplements are the best bioavailable source of iodine. This is required since there are plenty of iodine antagonists everywhere. While seafood does give us iodine, many of them are contaminated by toxins. Iodized salt does provide most people with the required quantity of

However, some people cannot utilize it well enough. Kelp supplements are also said to provide better benefits than pure iodine supplements since it contains a whole range of nutrients which can give multiple benefits.

Apart from iodine and minerals, kelp is also rich in folic acid, vitamins A, B, D, E, C and K, proteins and amino acids. 

Kelp supplements also improve metabolism rates, aid with better functioning of the liver, pituitary gland and pancreas, increases energy levels and acts as an anti-inflammatory agent. 

Dosage of Kelp Supplements

The dosage of kelp supplements depends on whether it is being used for specific health problems or just as a food supplement. For an under-active thyroid, it is recommended that a person take a maximum of 600mg kelp supplements daily.

Kelp can be taken raw, included in teas, tinctures or taken as a tablet.  

Since different kelp varieties contain different levels of iodine, the US law sets a limit of 225mcg of iodine to be provided by a single kelp supplement.

The strength of the capsules can vary from 200 – 400mg but users must ensure they check for the maximum dosage of iodine on the labels before purchase. Make sure that you take the right dosage and do not exceed daily recommended quantity.  

For general therapeutic purposes, levels of kelp should be at least 2 tsp of the liquid form of kelp supplements. As a general purpose supplement, kelp can treat obesity, constipation etc.  

 Some nutritionists consider liquid kelp is the best way to take this supplement as it is easily absorbed by the body. 


Kelp supplements are easily absorbed and utilized by the body. However, the quantity of iodine in kelp supplements varies from 45-57000 mcg per capsule.  

Hence, excess consumption of kelp supplements can lead to thyroid problems like hypothyroidism.   Some kelp supplements contain high levels of arsenic.

While sea water actually contains dilute arsenic, kelp like other sea vegetation and seafood contains concentrated levels of arsenic. This could cause poisoning in users and lead to various health problems.  

Those who are pregnant or breastfeeding, those on thyroid medications or suffer from any allergy must refer to their doctor before taking kelp supplements.

Kelp could slow blood clotting. Some other side effects of overuse of kelp supplements include abnormal bleeding, kidney problems and diarrhea and reduced blood sugar levels.

Hence, it is advised to stop using it a few weeks before and after surgery. Always follow recommended dosage levels mentioned on the product labels.

The actual daily dosage will vary depending on the age and health of the user. It is recommended that kelp supplements not be used continuously. Take periodic breaks of a few weeks and then restart usage to avoid overdose of iodine.  

7 thoughts on “What Is Ideal Dosage of Kelp Supplements”

  1. hi in your art you say stop taking for per of times ?
    i am 62 still working part time would i benefit from 400mg every day ,
    i am in general but i wonder would my thyroids do better with a cap a day ,
    i do manuel work
    many thanks

  2. I don't understand comment that "excess consumption of kelp supplements can lead to thyroid problems like hypothyroidism" I've been taking iodine for years to manage my hypothyroidism, please explain this comment.

    • (caps stuck...) i developed hypothyroidism from overdosing on kelp powder. there is too much of a good thing. now i take a much smaller amount daily to help manage my hypothyroidism.

  3. Good morning

    I am from South Africa and we are looking for Ascophyllum nodosum powder to buy on a regular basis.

    Thank you


Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.