How to read a Supplement Facts label
A Supplement Facts panel shows what's in a supplement and how much is in each serving. Give it about five minutes, and you'll know how to read one. You don't...
A Supplement Facts panel shows what's in a supplement and how much is in each serving. Give it about five minutes, and you'll know how to read one.
You don't need to be into fitness, or science, to care about what's in your cabinet.
Maybe you've wondered, "Why does my magnesium say glycinate?" Or why one vitamin D says 25 mcg and another says 1,000 IU. (Same amount, by the way: 25 mcg is 1,000 IU.)
Most of us started with a multivitamin and a couple of extras we picked up on a hunch. Nobody handed us a manual. So let's read one together.
This isn't about what to take. It's about knowing what you're looking at. If you take a medicine, are pregnant or nursing, or have a health condition, bring your labels to your pharmacist or doctor.
Our example: a Brightside packet
We'll use Brightside as the example. Brightside supplements come in daily packets, one packet a day. Our packs are curated by our pharmacist co-founder. Every box comes with a welcome booklet. It has one Supplement Facts page for each supplement.
The Supplement Facts panel follows a format set by federal rules. So if an ingredient or amount anywhere else ever looks different from your Supplement Facts pages, go with those pages, and let us know so we can fix it.
The panel below is made up for learning. It is not a real Brightside product, and the amounts are not from a Brightside pack.
An example Supplement Facts panel
Example panel, made up for learning. Not a real product.
| Amount Per Serving | % Daily Value | |
|---|---|---|
| Serving Size: 1 Capsule | ||
| Vitamin D (as cholecalciferol) | 20 mcg (800 IU) | 100% |
| Magnesium (as magnesium citrate) | 50 mg | 12% |
Other ingredients: rice flour, vegetable capsule (hypromellose).
The % Daily Values above are based on FDA's Daily Values for adults and children 4 years and older. This supplement is made up.
What's this part?
1. Serving size
It's like a recipe that says "1 cup flour." Every number below it is for that one serving. On the example panel, the serving is 1 capsule, so the numbers are for that one capsule.
Flipping between the pages in a Brightside booklet? Each one has its own serving size, so check it first. If a page lists a serving of 2 capsules, the amounts are for both together.
2. Amount per serving
This is how much of each thing is in one serving.
3. % Daily Value
You've seen this on a cereal box. On the example panel, vitamin D shows 100%, because 20 mcg is the Daily Value for vitamin D, a reference amount set by the FDA.
It's a yardstick, not a goal. Over 100% isn't a gold star, and under 100% isn't a fail. Your food counts too.
Some lines show a little symbol, like a star (*) or a dagger (†), instead of a percent. That means no Daily Value has been set.
4. The word in parentheses
"Magnesium (as magnesium citrate) 50 mg, 12% DV" tells you two things. Magnesium is what you're getting. Citrate is the form it's paired with. The 50 mg is the magnesium itself.
A few ingredients list the whole compound instead. The panel tells you which, so read the full line.
5. Blends and other ingredients
A "proprietary blend" gives one total for a group of ingredients, not the amount of each. That's allowed. You just know the total, not the split.
On Brightside packs, a few come in a proprietary blend, like the probiotic strains in The Routine and the Lion's Mane in Nine-to-Five. For those, the page shows the blend's total amount instead of the amount of each part. When each ingredient's amount is listed, it's easier to compare products, add up what you take, and get a clear answer from your pharmacist.
"Other ingredients," under the panel, are the things that hold a tablet together or make the capsule. It's also where you check for things you avoid, like gelatin or soy.
What do mg and mcg mean?
They're just sizes. A mg (milligram) is tiny. A mcg (microgram) is 1,000 times tinier. So 1,000 mcg equals 1 mg.
You may also see IU, an older unit. Current US labels must show vitamin D in mcg; IU may appear in parentheses. For vitamin D, 1 mcg equals 40 IU, so 25 mcg and 1,000 IU are the same amount. And "mcg RAE" or "mcg DFE" are just ways to count vitamin A or folate from different sources on one scale.
Is more better?
Not always. For many nutrients, experts set an upper limit: the most most people can take each day without a likely risk of harm. For most nutrients that counts food too, but for a few, like magnesium, the limit is for supplements only.
In a Brightside booklet, the same nutrient can show up on more than one page. It can also be in something else you take, and it all adds up. The NIH Office of Dietary Supplements lists these limits.
Can I trust what's on the label?
Fair question. In the US, supplement makers have to follow FDA manufacturing rules, called cGMP. Those rules cover how products are made, including checks that ingredients are what they are said to be. The FDA does not approve dietary supplements before they are sold, so it still helps to read the panel and ask the brand a few questions.
You can also ask a brand three things. What do you test for? How often: every batch, or some? Who does the testing?
Here's how Brightside handles it: Ingredients in our packs are third-party tested for potency and purity on a skip-lot basis by ISO 17025–accredited labs.
Questions for your pharmacist
Snap a photo of the Supplement Facts panel first, or bring your Brightside welcome booklet.
- Does this overlap with anything I already take?
- Is it OK with my medicines, or should I take them at different times?
- Is this serving size right for me?
- Should I skip anything while pregnant, nursing, or before a lab test?
- Is there an upper limit to watch across everything I take?
Try this
Pull today's Brightside packet from the bottom of the dispenser. Pick one supplement from the packet (a capsule, tablet or softgel) and find its page in the welcome booklet. Then find the serving size, one %DV, and one word in parentheses.
Look for those same three things on any Supplement Facts panel.
Frequently asked questions
What does a Supplement Facts panel show?
A Supplement Facts panel shows what's in a supplement and how much is in each serving. Give it about five minutes, and you'll know how to read one.
What is serving size?
Serving size is like a recipe that says "1 cup flour." Every number below it is for that one serving. In a Brightside welcome booklet, each Supplement Facts page has its own serving size, so check it first. If a page lists a serving of 2 capsules, the amounts are for both together.
What is % Daily Value?
% Daily Value is a yardstick, not a goal. Over 100% isn't a gold star, and under 100% isn't a fail. Your food counts too. Some lines show a little symbol, like a star (*) or a dagger (†), instead of a percent. That means no Daily Value has been set.
What do mg and mcg mean?
A mg (milligram) is tiny. A mcg (microgram) is 1,000 times tinier. So 1,000 mcg equals 1 mg. You may also see IU, an older unit. Current US labels must show vitamin D in mcg; IU may appear in parentheses. For vitamin D, 1 mcg equals 40 IU, so 25 mcg and 1,000 IU are the same amount.
What is a proprietary blend?
A proprietary blend gives one total for a group of ingredients, not the amount of each. That's allowed. You just know the total, not the split. On Brightside packs, a few come in a proprietary blend, like the probiotic strains in The Routine and the Lion's Mane in Nine-to-Five. For those, the page shows the blend's total amount instead of the amount of each part. When each ingredient's amount is listed, it's easier to compare products, add up what you take, and get a clear answer from your pharmacist.
Can I trust what's on the label?
In the US, supplement makers have to follow FDA manufacturing rules, called cGMP. Those rules cover how products are made, including checks that ingredients are what they are said to be. The FDA does not approve dietary supplements before they are sold, so it still helps to read the panel and ask the brand a few questions. Here's how Brightside handles it: Ingredients in our packs are third-party tested for potency and purity on a skip-lot basis by ISO 17025–accredited labs.
Where do I find the Supplement Facts for a Brightside pack?
Every Brightside box comes with a welcome booklet. It has one Supplement Facts page for each supplement in that order. Pull today's packet and match one supplement to its page.
Sources
- FDA, Nutrition labeling of dietary supplements, 21 CFR 101.36 (eCFR).
- FDA, Current Good Manufacturing Practice for dietary supplements, 21 CFR Part 111 (eCFR).
- NIH Office of Dietary Supplements, nutrient fact sheets and "Dietary Supplements: What You Need to Know" (ods.od.nih.gov).
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.