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Iodine

Also called potassium iodide, kelp.

The best price per 150 µg iodine and per month, form by form, across 5 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.

Potassium iodide

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, Potassium iodide: products ranked by price per 150 µg iodine
RankProductPer 150 µg iodinePer monthLastsBuyHow it is worked out
1
Ancient Purity Lugol's Iodine
Cheapest per doseLugol's IodineHealf · 50 ml · 450 servings · 12.5 mg a servingDetails and price historyAdd to my stack
under 1p2p102.7 years£22.49View 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: 450 (as stated on the label)
  • In the pack: 450 × 12.5 mg = 5,625 mg
  • £22.49 ÷ 5,625 mg × 150 µg = 0.06p per 150 µg
  • Amount per serving: stated on the label.
What the retailer's listing says
  • pack units “50ml”
  • servings stated “Servings per container: 450”
  • amount per serving “Iodine ; 12.5mg ; 8333%”
  • potassium iodide “Potassium Iodide ; 25mg”

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2
WeightWorld Iodine Tablets
Iodine TabletsWeightWorld · 365 servings · 400 µg a servingDetails and price historyAdd to my stack
1p31p2.7 years£9.99View at WeightWorld (opens in a new tab)Free delivery over £35.00, otherwise £1.99AmazonFind it on Amazon (opens in a new tab)A search, not a matched product. Price not compared.
Show the working
  • Servings: 365 (as stated on the label)
  • In the pack: 365 × 400 µg = 146 mg
  • £9.99 ÷ 146 mg × 150 µg = 1.03p per 150 µg
  • Amount per serving: stated on the label.
What the retailer's listing says
  • servings stated “Servings per Container: 365”
  • units per serving “Serving Size: 1 Tablet”
  • amount per serving “Iodine (as Potassium Iodide) ; 400 mcg”

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3
Codeage Iodine + - 2 fl oz
Iodine + - 2 fl ozHealf · 1,200 servings · 250 µg a servingDetails and price historyAdd to my stackclaimed: vegan
1p34p5.5 years£22.49View 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: 1200 (as stated on the label)
  • In the pack: 1200 × 250 µg = 300 mg
  • £22.49 ÷ 300 mg × 150 µg = 1.12p per 150 µg
  • Amount per serving: stated on the label.
What the retailer's listing says
  • servings stated “Servings Per Container: 1200”
  • units per serving “Serving Size: 1 Drop”
  • amount per serving “Iodine (as Potassium Iodide) ; 250 mcg”

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4
MaryRuth's Iodine Drops - Unflavoured - 1 oz
Iodine Drops - Unflavoured - 1 ozHealf · 450 servings · 250 µg a servingDetails and price historyAdd to my stackUnflavoured
2p63p2.1 years£15.65View 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: 450 (as stated on the label)
  • In the pack: 450 × 250 µg = 112.5 mg
  • £15.65 ÷ 112.5 mg × 150 µg = 2.09p per 150 µg
  • Amount per serving: stated on the label.
What the retailer's listing says
  • servings stated “Servings Per Container: 450”
  • units per serving “2 Drops (0.07mL)”
  • amount per serving “Iodine (as Potassium Iodide) ; 250 mcg”

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5
KIKI Health Ionic Iodine Liquid Concentrate
Ionic Iodine Liquid ConcentrateHealf · 50 ml · 384.6 servings · 300 µg a servingDetails and price historyAdd to my stack
3p76p2.1 years£19.50View 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: 50 ÷ 0.13 per serving = 384.6
  • In the pack: 384.6 × 300 µg = 115.4 mg
  • £19.50 ÷ 115.4 mg × 150 µg = 2.54p per 150 µg
  • Amount per serving: stated on the label.
What the retailer's listing says
  • pack units “50ml”
  • units per serving “take 2 drops (0.13ml) daily”
  • amount per serving “300 mcg of iodine per serving”

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6
Nature's Best Iodine 150µg - for Normal Thyroid, Cognitive and Neurological Function
Best value under 6 months' supplyIodine 150µg - for Normal Thyroid, Cognitive and Neurological Function180 tablets · 180 servings · 150 µg a servingDetails and price historyAdd to my stackclaimed: veganclaimed: vegetarian
4p£1.256 months£7.50View at Lamberts Healthcare (Nature's Best) (opens in a new tab)Free delivery over £20.00, otherwise £2.50AmazonFind it on Amazon (opens in a new tab)A search, not a matched product. Price not compared.
Show the working
  • Servings: 180 ÷ 1 per serving = 180
  • In the pack: 180 × 150 µg = 27 mg
  • £7.50 ÷ 27 mg × 150 µg = 4.17p per 150 µg
  • Amount per serving: stated on the label.
What the retailer's listing says
  • pack units “Specifications: 180 Tablets”
  • amount per serving “each one of our tablets supplies 150µg of free elemental iodine in the form of potassium iodide”

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7
Pure Encapsulations Iodine (potassium iodide)
Iodine (potassium iodide)Healf · 60 capsules · 60 servings · 225 µg a servingDetails and price historyAdd to my stackclaimed: vegetarian
9p£2.673 months£8.00View 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 ÷ 1 per serving = 60
  • In the pack: 60 × 225 µg = 13.5 mg
  • £8.00 ÷ 13.5 mg × 150 µg = 8.89p per 150 µg
  • Amount per serving: stated on the label.
What the retailer's listing says
  • pack units “60 caps”
  • servings stated “Servings Per Container: 60”
  • units per serving “Serving Size: 1 capsule”
  • amount per serving “Iodine (as Potassium Iodide) ; 225 mcg”

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8
Pure Encapsulations Iodine & Tyrosine
Iodine & TyrosineHealf · 60 capsules · 60 servings · 225 µg a servingDetails and price historyAdd to my stackalso contains tyrosineclaimed: vegetarian
31p£9.413 months£28.23View 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 ÷ 1 per serving = 60
  • In the pack: 60 × 225 µg = 13.5 mg
  • £28.23 ÷ 13.5 mg × 150 µg = 31.4p per 150 µg
  • Amount per serving: stated on the label.
  • Also contains: tyrosine. The price counts the iodine only.
What the retailer's listing says
  • pack units “60 caps”
  • servings stated “Servings Per Container: 60”
  • units per serving “Serving Size: 1 capsule”
  • amount per serving “Iodine (as Potassium Iodide) ; 225 mcg ; 150%”

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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.

Conversion factor used when only the compound weight is given: potassium iodide 76.4%. How we chose these.

Questions

Where can I buy iodine cheapest in the UK?

On 20 October 2026, the cheapest iodine per dose from a UK seller was Lugol's Iodine at Healf (under 1p per 150 µg iodine, 2p a month). Then Iodine Tablets at WeightWorld (1p per 150 µg iodine, 31p a month) and Iodine + - 2 fl oz at Healf (1p per 150 µg iodine, 34p a month). That is by price per 150 µg iodine, across 3 UK retailers and 8 products, with every price checked daily; the table above shows the working for each.

What is the best price per 150 µg iodine of iodine today?

under 1p per 150 µg iodine, for Lugol's Iodine at Healf (under 1p per 150 µg iodine, 2p a month), on 20 October 2026. The dearest of the 8 products we price is 31p per 150 µg iodine, and the middle one is 2p.

How much does iodine cost per month?

At one 150 µg dose a day, the cheapest works out at 2p a month, for Lugol's Iodine at Healf, on 20 October 2026. Across the 8 products we price it runs from 2p to £9.41 a month. A month is 30 days, and the figure follows the dose you enter in the table.

Which iodine form is cheapest per dose?

On 20 October 2026: potassium iodide from under 1p per 150 µg iodine (Healf) and kelp from 6p per 150 µg iodine (Simply Supplements). The forms differ in what they contain, so this is a fact about price and not a recommendation of one over another.

Do bigger iodine packs cost less per dose?

Mostly, yes: on 20 October 2026, the 5 packs that last more than six months average 1p per 150 µg iodine, against 15p for the 3 that last six months or less. The table marks the cheapest pack that lasts six months or less as the best value for anyone who would rather not buy a year at once.

How long does a pack of iodine last?

At one 150 µg dose a day, the packs we price last from 3 months to 102.7 years; the middle one lasts 2.1 years. Each row says how long its pack lasts at the dose you enter.

What does “per 150 µg iodine” mean?

It is the unit we use to put every product on the same scale: the price of 150 µg of elemental iodine, whatever the pack size or serving size. It is a comparison unit, not a recommendation of how much to take. Use the “Your daily dose” box to see costs at the amount you actually take.

Why are the iodine forms in separate tables?

We only rank products against others of the same form, because someone buying one form would not usually see another as a like-for-like substitute on price. Forms we compare separately: Potassium iodide; Kelp.

Why is a product I have seen in the shops missing?

If a retailer’s listing does not let us confirm the amount per serving, the pack size or the form, we do not guess and we do not show the product. It appears once its label has been read and confirmed.

How up to date are the prices?

Prices on this page were last checked on 20 October 2026. Every table shows the date its prices were checked. Always confirm the price on the retailer’s site before buying.

Do retailers pay to appear higher?

No. We earn a commission when you buy through our links, but the order is set only by price per dose. No retailer or brand can pay for position.