A supplement can look straightforward on the front of the pack and surprisingly complicated on the back. Does “1,000 mg” mean one capsule or a full serving? Is a tub with 60 capsules a two-month supply? And does a higher percentage next to a vitamin mean it is a better choice?

Start with three things: the serving size, the amount of each ingredient in that serving, and the directions for daily use. Once those are clear, the rest of the label becomes much easier to understand.

This SupplementHQ guide explains how to compare labels with confidence. All numerical product examples below are fictional and illustrate label reading, not personal dosage recommendations.

1. Start with serving size and daily directions

A serving size is the quantity used for the amounts shown in a particular table. It might be one tablet, two capsules, three gummies or a measured amount of powder. The recommended daily portion tells you how much the manufacturer instructs you to take each day. Read both: a serving is not automatically a whole day’s supply.

Check whether the table says per capsule, per serving, per daily portion or per 100 g. A per-100-g figure helps compare products by weight, but usually does not describe the amount you will actually take.

For powders, follow the specified gram amount and whether the scoop should be level or heaped. Scoops from different products are not interchangeable. A scoop measures volume, and powder density affects its weight. If you need to check a serving, use scales suitable for that quantity; ordinary kitchen scales are not suitable for measuring tiny milligram amounts.

2. Understand grams, milligrams and micrograms

The unit matters just as much as the number. A figure of 1,000 micrograms is much smaller than 1,000 milligrams.

For example, 5,000 micrograms equals 5 mg, not 5,000 mg. Do not use one universal conversion for IU: different vitamins have different conversions. See the NHS explanation of vitamin and mineral units.

3. Read the ingredients list and the amounts table together

The ingredients list tells you what has gone into the product. The amounts table tells you how much of the declared nutrients or other substances you get in the stated portion. You need both to make a useful comparison.

Ingredients are generally listed in descending order by weight, with some exceptions. Position alone does not tell you an exact dose. The Food Standards Agency’s labelling guidance explains ingredient declarations and allergen highlighting.

Look beyond the headline ingredient. A capsule may also contain a shell, bulking agents or anti-caking agents. A flavoured powder may contain flavourings and sweeteners. These serve practical functions; a longer ingredients list is not automatically evidence of poor quality. Decide whether the formula suits your preferences and dietary requirements.

Check precisely what the stated weight refers to. The total weight of a mineral compound is not necessarily the amount of the mineral itself. If a label distinguishes a compound amount from the magnesium it provides, compare the declared magnesium amount between products. Likewise, a blend’s total weight does not reveal each component’s quantity when individual amounts are not provided. You will often see this on pre-workout labels; our pre-workout guide explains how to compare them. Ask the manufacturer if the information is unclear.

4. What does %NRV mean?

NRV stands for Nutrient Reference Value. It is a standard reference used on vitamin and mineral labels. The percentage tells you how the amount in the stated portion compares with that reference.

Vitamin C has a labelling NRV of 80 mg. A portion containing 40 mg would provide 50% NRV; 80 mg would provide 100%; and 160 mg would provide 200%. The Health and Food Supplements Information Service explains NRVs and their role in labelling.

%NRV is not a personalised target, a measure of absorption or a safety limit. A higher percentage does not automatically make a product more suitable. Your needs can depend on diet, age and circumstances. Ingredients such as creatine or collagen do not have a vitamin-and-mineral NRV; a dash in that column does not mean there is none of the ingredient in the product.

5. Check allergens and dietary suitability

Read the full ingredients list every time you buy, including when repurchasing a familiar product: formulations can change. Relevant regulated allergens should be emphasised, often in bold. Whey, for example, comes from milk. Read any “may contain” statement too, as it concerns possible unintended allergen presence. The FSA’s allergy guidance explains how to use this information.

If you need a vegan, vegetarian or halal product, check the specific product’s statement and any applicable certification. Do not infer suitability from the brand name, a plant image or the main ingredient alone. Capsule shells and other ingredients matter too.

6. Read warnings before adding a product to your routine

Check the age guidance, daily directions, storage instructions and best-before date. Food supplements carry warnings about exceeding the recommended amount, keeping them away from young children and not using them to replace a varied diet. The FSA’s food supplement guidance sets out the information consumers should find on these products.

Compare a new product with supplements you already take so you can spot repeated ingredients. For example, a multivitamin and a separate vitamin product may both contribute the same nutrient. Do not assume each product’s directions account for everything else in your routine.

If you take medicines, have a medical condition, are pregnant or breastfeeding, or are choosing a supplement for a child, check suitability with a pharmacist or another qualified healthcare professional. Supplements can interact with medicines; the NHS vitamin and mineral guide also explains that excessive intakes can carry risks.

7. Compare cost per serving, not just the bottle price

A bigger bottle or lower price does not always mean better value. Work out how many labelled servings you receive, then compare products with similar ingredient amounts and forms.

In this example, Product B costs more upfront but less per serving. That comparison is useful only if the formula and ingredient amount are comparable and suitable for you. Include delivery costs and consider whether you will use the pack before its best-before date.

Your quick supplement label checklist

• What is one serving, and what do the daily directions say?
• Are ingredient amounts shown per capsule, serving, daily portion or 100 g?
• Have I checked the units and the amount of the actual nutrient?
• Do I understand the %NRV without treating it as a personal target?
• Have I checked allergens, dietary suitability and warnings?
• Does it duplicate anything I already take?
• How many servings will I receive, and what is the cost per serving?

Frequently asked questions

Does “60 capsules” mean a 60-day supply?

Only if the directions specify one capsule per day. At two capsules daily, 60 capsules lasts 30 days.

Is a higher-strength supplement always better?

No. The useful question is whether the ingredient, amount and formulation suit your needs. A larger number on the front of the pack is not enough to decide.

What if the website and the pack show different information?

Check the label on the actual product and contact the retailer or manufacturer to resolve the difference before taking it. Online images may show an earlier formulation or a different pack size.

Ready to compare options? Browse the SupplementHQ range and use the checklist alongside each product’s label. If a label image is unclear, ask for the information before you order.

General educational information, not individual medical advice. Product examples and images are illustrative and do not represent specific products or recommended doses.