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Kelp (iodine)

Also called potassium iodide, kelp.

The best price per 150 µg iodine and per month across 3 UK retailers, and where to buy it cheapest. A unit for comparing, not advice.

Comparing iodine

Labels give iodine in micrograms, and some in milligrams: 150 µg is 150 mcg. We put every product in one unit before pricing it. Iodine comes as potassium iodide and kelp, and each form has its own table, because someone buying one would not usually take another as a like-for-like substitute. Products that combine iodine with other ingredients are listed separately, because their price buys more than iodine. 150 µg is our unit for comparing prices, not a dose to take: the label’s directions and a pharmacist decide that.

Prices last checked: . Ranked purely by price per 150 µg iodine — a comparison unit, not a recommendation. We earn commission when you buy through these links; it never affects the order.

Compared at 150 µg. Enter the amount you take to see your own costs.

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Iodine, Kelp: products ranked by price per 150 µg iodine
RankProductPer 150 µg iodinePer monthLastsBuyHow it is worked out
1
Simply Supplements Sea Kelp Capsules 4200mg
Cheapest per doseSea Kelp Capsules 4200mg120 capsules · 40 servings · 600 µg a servingDetails and price historyAdd to my stack
6p£1.875 months£9.99View at Simply Supplements (opens in a new tab)Free delivery from £20.00, otherwise £1.99AmazonFind it on Amazon (opens in a new tab)A search, not a matched product. Price not compared.
Show the working
  • Servings: 120 ÷ 3 per serving = 40
  • In the pack: 40 × 600 µg = 24 mg
  • £9.99 ÷ 24 mg × 150 µg = 6.24p per 150 µg
  • Amount per serving: stated on the label.
What the retailer's listing says
  • confirmed values “confirmed from the retailer's own product page, not this listing's text: form id kelp; amount per serving 600.0; amount unit mcg; amount refers to elemental; units per serving 3.0; pack units 120; pack unit type capsule”

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2
Together Health Iodine
Iodine30 capsules · 30 servings · 293 µg a servingDetails and price historyAdd to my stackclaimed: vegan
12p£3.5859 days£6.99View at Together Health (opens in a new tab)Free delivery over £11.00, otherwise £1.00AmazonFind it on Amazon (opens in a new tab)A search, not a matched product. Price not compared.
Show the working
  • Servings: 30 ÷ 1 per serving = 30
  • In the pack: 30 × 293 µg = 8.79 mg
  • £6.99 ÷ 8.79 mg × 150 µg = 11.9p per 150 µg
  • Amount per serving: stated on the label.
What the retailer's listing says
  • pack units “1 capsule provides on average (NRV)”
  • units per serving “1 capsule provides on average (NRV)”
  • amount per serving “Iodine 293 mcg 195%”
  • confirmed values “confirmed from the retailer's own product page, not this listing's text: form id kelp; amount per serving 293.0; amount unit mcg; amount refers to elemental; pack units 30; pack unit type capsule; units per serving 1.0”

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3
Rosita 5 Seaweed Blend
5 Seaweed BlendHealf · 60 capsules · 30 servings · 150 µg a servingDetails and price historyAdd to my stackclaimed: veganclaimed: vegetarian
78p£23.4930 days£23.49View at Healf (opens in a new tab)Free delivery over £50.00, otherwise £3.99AmazonFind it on Amazon (opens in a new tab)A search, not a matched product. Price not compared.
Show the working
  • Servings: 60 ÷ 2 per serving = 30
  • In the pack: 30 × 150 µg = 4.5 mg
  • £23.49 ÷ 4.5 mg × 150 µg = 78.3p per 150 µg
  • Amount per serving: stated on the label.
What the retailer's listing says
  • pack units “60 Capsules”
  • servings stated “Servings Per Container: 30”
  • units per serving “Serving Size: 2 Capsules”
  • amount per serving “Iodine ; 150 mcg ; 100%”

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By shop

Each shop's iodine products, with where its cheapest sits in the market.

How we work out these prices

We count the elemental iodine a product provides, not the weight of the whole compound it comes in. If a label states the iodine amount, we use it. If it only gives the compound's weight, we estimate using a published conversion factor and mark the figure “estimated”. If we cannot tell which the number means, the product is left out until it can be confirmed.

Our full method · All iodine forms