How to read a supplement label

Find the serving before the headline number

Turn the pack around before comparing the largest number on its front. Find the serving description, then the amount of each ingredient in that serving. A serving might mean one capsule, several capsules or a measured quantity of powder.

For example, an imaginary label stating 200 mg per two capsules gives 100 mg per capsule. That is arithmetic for comparing labels, not a recommendation to take either amount. Keep the label instruction beside your calculation.

Check identity, form and units

Write down the full ingredient name, its preparation and its unit. A plant powder and an extract are different preparations. The total mass of a mineral compound can also differ from the amount of the mineral it provides.

Keep grams, milligrams and micrograms distinct: 1 g equals 1,000 mg, and 1 mg equals 1,000 micrograms. A bigger printed number can simply mean a smaller unit.

Read the information around the ingredients

UK supplement labelling includes use instructions and warnings, ingredient amounts and business information. Before making a decision, check:

• The complete ingredient list and emphasised allergens.
• The recommended daily amount and warning not to exceed it.
• Storage instructions, best-before date and the responsible business.
• Whether a certification claim links to a record for that exact product.

A transparent label answers one question

It tells you what the manufacturer declares is inside. Whether an ingredient has useful evidence is a separate question. Whether a combination is appropriate for you is another.

Save a clear photograph of the full label if you need to discuss it with a pharmacist.