Start with the Supplement Facts panel
The front of a bottle identifies a product; it rarely provides everything needed to assess the formula. Read the Supplement Facts panel alongside directions, warnings and other ingredients. FDA’s labeling guidance explains how serving information and dietary ingredients are presented. FDA: Supplement Facts and nutrition labeling
For an online purchase, ask for readable photographs of every panel. A promotional graphic, an ingredient illustration and a list in a review are different sources. Keep track of which one you actually have.
Separate bottle size from serving size
A bottle’s total liquid volume is not the dose. Likewise, the amount printed beside an ingredient must be read in the context of the stated serving. Comparing only the largest number on two labels can produce a misleading comparison.
| Check | Question to answer |
|---|---|
| Serving size | How much product does the panel describe? |
| Servings per container | How many labeled servings are in the bottle? |
| Amount per serving | Is this an individual component amount or a combined amount? |
| Directions | Do they identify how to measure and use the product? |
For example, imagine two fictional products: one lists a quantity per capsule and another per two-capsule serving. The printed numbers cannot be compared as though they were both per capsule. This is a reading example, not a dosing recommendation.
What does a proprietary blend tell you?
FDA’s guidance allows certain ingredients to appear within a proprietary blend, with a total blend weight and components listed in descending order by weight. That total does not reveal each component’s amount. FDA proprietary-blend guidance
Do not divide the total equally between the listed ingredients. Do not assume the first ingredient accounts for a particular percentage. Without individual quantities, a precise comparison with a study may be impossible. A missing quantity is a limitation to record, not a number to estimate.
Make a label-check note before buying
- Save the product name and the date of the label image.
- Copy the stated serving size exactly, including units.
- List the quantities that are actually disclosed.
- Mark anything unreadable or undisclosed as unknown.
- Read other ingredients and warnings, rather than only highlighted components.
- Take the full label and your medication list to a pharmacist if you need suitability advice.
NCCIH notes that supplements can interact with medicines and that commercial products may differ from those used in studies. A readable label is a starting point, not personal medical clearance. NCCIH: Using dietary supplements wisely
Apply the check to Yu Sleep
Our Yu Sleep ingredient guide identifies which amounts were available to this review and which were not verified. It does not reconstruct a missing back label.
Use the safety guide for ingredient-related cautions. If your next question is whether a cited study applies to the product, read how to evaluate supplement research.
Sources & references
Checked September 18, 2026. Citations describe the scope of the material reviewed, not an endorsement of the product.
