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Say what you want help with. The finder shows what the GB register lets any seller claim for it, what the register assessed and refused, and the cheapest capsules per capsule for each ingredient. It quotes; it never advises.

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Where the register allows less than sellers suggest

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Seller-stated only: vegan means the seller says vegan.

Metabolism and Thyroid and Muscles

1359 capsules across 46 ingredients

Metabolism. The register's phrase is 'contributes to normal energy-yielding metabolism', and many everyday vitamins and minerals hold it. It is not a claim about weight or about feeling energetic, which is why this goal sits apart from Weight and from Tiredness and fatigue. Wording is quoted exactly on each ingredient page.

Thyroid. Only iodine and selenium hold authorised register wording about the thyroid, quoted exactly on their pages. Thyroid conditions are diagnosed and managed by a GP, and the British Thyroid Foundation is the specialist charity.

Muscles. Ingredients here hold register claims relating to normal muscle function or muscle protein, quoted exactly on their pages. Resistance exercise and overall protein intake are the fundamentals the claims assume; the NHS exercise guidance below is a good starting point.

Nothing here is medical advice. The wording is the GB register's, quoted exactly; whether a product qualifies to use it is the seller's responsibility. Speak to a GP or pharmacist before taking a supplement, especially if you are pregnant, take medicines or have a diagnosed condition. Wording from the GB nutrition and health claims register; mapping reviewed 4 September 2026.

Holds an authorised claim

Magnesium

2 authorised claims · 27 capsules · ingredient page
  • “Magnesium contributes to normal muscle function” · Muscles
  • “Magnesium contributes to normal energy-yielding metabolism” · Metabolism

Not authorised for metabolism: the register refused 2 claims there.

All 27 magnesium capsules

Vitamin C

1 authorised claim · 17 capsules · ingredient page
  • “Vitamin C contributes to normal energy-yielding metabolism” · Metabolism

All 17 vitamin c capsules

Vitamin D

2 authorised claims · 13 capsules · ingredient page
  • “Vitamin D contributes to the maintenance of normal muscle function” · Muscles
  • “Vitamin D helps to reduce the risk of falling associated with postural instability and muscle weakness. Falling is a risk factor for bone fractures among men and women 60 years of age and older.” · Muscles

Not authorised for thyroid: the register refused 1 claim there.

All 13 vitamin d capsules

Zinc

4 authorised claims · 12 capsules · ingredient page
  • “Zinc contributes to normal carbohydrate metabolism” · Metabolism
  • “Zinc contributes to normal macronutrient metabolism” · Metabolism
  • “Zinc contributes to normal metabolism of fatty acids” · Metabolism
  • “Zinc contributes to normal metabolism of vitamin A” · Metabolism

Not authorised for thyroid or muscles: the register refused 2 claims there.

All 12 zinc capsules

Vitamin B6

3 authorised claims · 10 capsules · ingredient page
  • “Vitamin B6 contributes to normal energy-yielding metabolism” · Metabolism
  • “Vitamin B6 contributes to normal homocysteine metabolism” · Metabolism
  • “Vitamin B6 contributes to normal protein and glycogen metabolism” · Metabolism

All 10 vitamin b6 capsules

Biotin

2 authorised claims · 9 capsules · ingredient page
  • “Biotin contributes to normal energy-yielding metabolism” · Metabolism
  • “Biotin contributes to normal macronutrient metabolism” · Metabolism

All 9 biotin capsules

Calcium

2 authorised claims · 5 capsules · ingredient page
  • “Calcium contributes to normal muscle function” · Muscles
  • “Calcium contributes to normal energy-yielding metabolism” · Metabolism

Not authorised for metabolism: the register refused 1 claim there.

All 5 calcium capsules

Niacin

1 authorised claim · 5 capsules · ingredient page
  • “Niacin contributes to normal energy-yielding metabolism” · Metabolism

All 5 niacin capsules

Potassium

1 authorised claim · 5 capsules · ingredient page
  • “Potassium contributes to normal muscle function” · Muscles

All 5 potassium capsules

Copper

1 authorised claim · 4 capsules · ingredient page
  • “Copper contributes to normal energy-yielding metabolism” · Metabolism

All 4 copper capsules

Iron

1 authorised claim · 4 capsules · ingredient page
  • “Iron contributes to normal energy-yielding metabolism” · Metabolism

Not authorised for muscles or metabolism: the register refused 2 claims there.

All 4 iron capsules

Choline

2 authorised claims · 3 capsules · ingredient page
  • “Choline contributes to normal homocysteine metabolism” · Metabolism
  • “Choline contributes to normal lipid metabolism” · Metabolism

Chromium

1 authorised claim · 3 capsules · ingredient page
  • “Chromium contributes to normal macronutrient metabolism” · Metabolism

Not authorised for metabolism: the register refused 2 claims there.

creatine

2 authorised claims · 3 capsules · ingredient page
  • “Daily creatine consumption can enhance the effect of resistance training on muscle strength in adults over the age of 55.” · Muscles
  • “Creatine increases physical performance in successive bursts of short-term, high intensity exercise” · Muscles

Not authorised for muscles: the register refused 3 claims there.

Folate

1 authorised claim · 3 capsules · ingredient page
  • “Folate contributes to normal homocysteine metabolism” · Metabolism

Selenium

1 authorised claim · 3 capsules · ingredient page
  • “Selenium contributes to the normal thyroid function” · Thyroid

Manganese

1 authorised claim · 2 capsules · ingredient page
  • “Manganese contributes to normal energy-yielding metabolism” · Metabolism

Molybdenum

1 authorised claim · 2 capsules · ingredient page
  • “Molybdenum contributes to normal sulphur amino acid metabolism” · Metabolism

Not authorised for metabolism: the register refused 1 claim there.

Pantothenic Acid

2 authorised claims · 1 capsule · ingredient page
  • “Pantothenic acid contributes to normal energy-yielding metabolism” · Metabolism
  • “Pantothenic acid contributes to normal synthesis and metabolism of steroid hormones, vitamin D and some neurotransmitters” · Metabolism

Riboflavin

2 authorised claims · 1 capsule · ingredient page
  • “Riboflavin contributes to normal energy-yielding metabolism” · Metabolism
  • “Riboflavin contributes to the normal metabolism of iron” · Metabolism

Vitamin A

1 authorised claim · 1 capsule · ingredient page
  • “Vitamin A contributes to normal iron metabolism” · Metabolism

Not authorised for muscles: the register refused 1 claim there.

Vitamin B12

2 authorised claims · 1 capsule · ingredient page
  • “Vitamin B12 contributes to normal energy-yielding metabolism” · Metabolism
  • “Vitamin B12 contributes to normal homocysteine metabolism” · Metabolism

Assessed by the register and not authorised

The register looked at claims for these relating to metabolism and thyroid and muscles and turned them down. Sellers may not make them. Prices are shown for ingredients you named; the rest link to their register page.

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