A supplement label is not a promise. It is a starting point: a compact record of what is in the product, how much is in a serving, and who stands behind it.
Start with the serving size.
The Supplement Facts panel lists dietary ingredients and the amount provided per serving. Before comparing two products, make sure you are comparing the same unit: one strip, two strips, a scoop, or a capsule. A larger number on the front of a bottle may simply refer to a different serving size.
Look beyond the headline ingredient.
Names on the front panel are usually the beginning of the story, not the whole story. The label should also identify the amount per serving, any established Daily Value, directions for use, and other ingredients such as flavors or binders. For botanical ingredients, the label can also identify the part of the plant used.
Know the difference between a role and a remedy.
Supplement labels can include different kinds of statements. A structure/function statement describes a role in normal body structure or function; a health claim characterizes a relationship to disease risk and has a different FDA framework. If copy feels like it is promising to diagnose, treat, cure, or prevent a disease, that is a useful reason to slow down and look for the underlying evidence.
A useful final question
Can the company show the current label, clear directions, and product-specific documentation? Those basics do not answer every question, but they make it easier to make a more informed choice.