"Highly bioavailable" appears on an enormous number of supplement packs. Very few of them mean anything precise by it.
The actual definition
Bioavailability is the proportion of an administered substance that reaches the systemic circulation in a form the body can use. It is expressed as a percentage, and it is measured — typically by taking blood samples over time and comparing the resulting curve against an intravenous reference.
Why the word gets abused
Because it sounds technical and is rarely challenged. A brand can write "superior bioavailability" without ever having measured anything, and most customers have no way to check.
What a real claim needs
A specific comparison (against what?), a measured result, and ideally the study design. "More bioavailable" with no comparator is not a claim, it is a mood.
The regulatory position
In Great Britain, absorption and bioavailability claims are not on the authorised health claims list. That means a brand cannot lawfully make them for a food supplement without going through a specific process.
This is why our pages describe our spray by what it contains and how it is used, not by how well it is supposedly absorbed.
