About the File

The Ingredient File is an independent reference project with a narrow focus: reading supplement labels line by line and explaining what the research behind each ingredient actually supports — no more, no less.

It is written and maintained by Daniel Foster, a label-literacy writer who got into this niche the way most people do: by buying a beautifully marketed supplement, flipping the bottle over, and realizing the back label told a very different story than the front.

Method

• Start from the physical label. Doses, salt forms, blend totals, "other ingredients" — the analysis begins with what is printed, not what is advertised.
• Grade the evidence, not the product. When we call an ingredient "well studied" or "emerging", we are describing the state of published human research on that ingredient in general — never a verdict on any specific brand.
• Disclose the gaps. Proprietary blends, undisclosed doses, missing CFU counts — if the label doesn't tell us, the analysis says so, every time.

Standards

Primary sources (NIH Office of Dietary Supplements fact sheets, peer-reviewed trials) outrank secondary coverage, always. We do not accept sponsorships from supplement brands, and we do not run display advertising. Found an error in a dose or a citation? Our corrections inbox is open.