Supplement Basics

How to Read a Supplement Facts Label: A Practical Walkthrough

Written and reviewed by the Best Wellness Guide Editorial Team · Last updated 2026-10-20

This article is for general information only and is not medical advice. Talk to a licensed healthcare provider before starting any supplement. Some links on this page are affiliate links: if you buy through them we may earn a commission at no extra cost to you. See our Affiliate Disclosure and Medical Disclaimer.

Every dietary supplement sold in the United States has to carry a Supplement Facts panel. It is the single most useful thing on the bottle, and it is also the part most shoppers glance at for two seconds before turning back to the front label, where the marketing lives. This guide walks through the panel from top to bottom so you can compare two products on what is actually inside them rather than on how confident the packaging sounds.

Start with the serving size, not the bottle count

The first line of the panel tells you the serving size: one capsule, two gummies, one scoop. Everything listed below that line refers to one serving, not one capsule. This matters more than it sounds. A product that advertises "500 mg" on the front may need three capsules to reach that number, which changes both the daily cost and how realistic it is to take every day.

Next to serving size you will usually see "servings per container." Divide the price by that number and you get the real cost per day. Two bottles that both say "60 count" can last 60 days or 20 days depending on the serving size. When you compare products, compare cost per serving, never cost per bottle.

Amount per serving and percent Daily Value

Below the serving information, each ingredient appears with its amount per serving, in milligrams (mg), micrograms (mcg) or sometimes International Units for certain vitamins. Many vitamins and minerals also show a percent Daily Value (%DV). That percentage compares the amount in one serving with a reference intake set for labeling purposes.

A few things trip people up here. First, a %DV above 100 is common and is not automatically a problem, but very high percentages of fat-soluble vitamins such as A, D, E and K deserve a conversation with a pharmacist because those vitamins can build up in the body. Second, many botanical ingredients and specialty compounds have no established Daily Value at all. In that case the label shows an asterisk and a footnote reading "Daily Value not established." That does not mean the ingredient is unsafe or useless. It means there is no official reference number to compare against.

What a proprietary blend actually tells you

A proprietary blend groups several ingredients under one name with a single combined weight. The label must list the ingredients inside the blend in descending order by weight, but it does not have to say how much of each one is present.

Here is why that matters. Imagine a 600 mg blend that lists eight ingredients. The first one could be 590 mg and the other seven could share the remaining 10 mg. You cannot tell from the label. Brands use blends for legitimate reasons, including protecting a formula from copycats, but blends make direct comparison harder. When two products are otherwise similar, the one that lists each ingredient's amount gives you more to work with.

Other ingredients: fillers, capsules and allergens

Under the main panel there is usually a line called "Other ingredients." This is where you find capsule material (gelatin or a plant-based alternative such as hypromellose), flow agents like magnesium stearate or rice flour, sweeteners, colors and flavors. None of these are red flags on their own, but they matter if you are vegetarian, avoid certain sweeteners or have food allergies.

Look for an allergen statement as well. Products containing major food allergens such as milk, soy, wheat, tree nuts or shellfish are expected to say so. If you have a serious allergy and the label is unclear, contact the manufacturer before buying rather than after.

Warnings, directions and the fine print

The directions section tells you how the manufacturer intends the product to be used: with food or without, morning or evening, how many servings per day. Following those directions matters because the amounts on the panel were chosen with them in mind.

Warnings are easy to skip and worth reading. Common ones include "consult your physician if pregnant, nursing or taking medication," "keep out of reach of children," and specific cautions for ingredients that can interact with blood thinners or blood pressure medication. If a warning mentions a condition you have or a medication you take, that is your cue to check with a pharmacist first.

The disclaimer that appears on almost every bottle

If a supplement label describes how a product supports a body structure or function, it must also carry this sentence: "These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease." That text is required, not a sign that something is wrong. It reflects the fact that supplements are not reviewed the way prescription drugs are before they reach the market. Our guide to how supplements are regulated explains this in more detail.

A five-minute label checklist

Serving size and how many units it takes per day
Cost per serving, calculated from servings per container
Individual ingredient amounts, or a proprietary blend that hides them
Any vitamin or mineral well above 100% DV, especially A, D, E and K
Other ingredients and allergen statement
Warnings that mention your medications or conditions
Manufacturer name and contact details printed on the label

A worked example

Say you are comparing two magnesium products. Product A costs $24 for 60 capsules, serving size two capsules, 300 mg of magnesium per serving. Product B costs $19 for 90 capsules, serving size three capsules, 250 mg per serving. Product A gives you 30 servings at about 80 cents each. Product B gives you 30 servings at about 63 cents each, but with less magnesium per serving and an extra capsule every day. Neither is automatically better. The label just lets you see the trade-off clearly instead of guessing from the front of the bottle.

Putting it to use

Reading labels well turns a confusing aisle (or a long sales page) into a simple comparison. Once you know the serving size, the real cost per day and how transparent the ingredient list is, the marketing headlines matter much less. If you are comparing products in a specific category, our buyer guides for dental health, brain wellness and joint support apply this same label-first approach, and the supplements comparison hub puts the featured offers side by side.

This article is educational and should not replace advice from a licensed healthcare provider.

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FAQ

Is a proprietary blend a bad sign?

Not necessarily. It simply means the label shows a combined weight for several ingredients instead of individual amounts. It makes comparison harder, so transparent labels are easier to evaluate.

What does 'Daily Value not established' mean?

It means there is no official reference intake for that ingredient, which is common for botanicals and specialty compounds. It is not a statement about safety or effectiveness.

Should I worry if a vitamin is listed above 100% DV?

Not automatically, but very high amounts of fat-soluble vitamins such as A, D, E and K are worth discussing with a pharmacist, especially if you take other supplements.

Where do I find allergen information?

Check the 'Other ingredients' line and any allergen statement near the panel. If it is unclear and you have a serious allergy, contact the manufacturer before buying.