Stem cell viability refers to the proportion of cells in a preparation that are alive and intact at the point of measurement. It is expressed as a percentage and is one of the checks performed before administration. A count alone says nothing about condition, which is why viability is reported alongside it.
Ask when viability is assessed, since a figure taken at one stage may differ from the condition of cells at administration. Handling, temperature, and time between preparation and use all matter. Ask whether the clinic measures viability immediately before treatment and whether that result is documented and available to you on request.
Viability is a useful indicator rather than a prediction of outcome. A high figure describes the preparation, not what will happen afterward, and it should not be presented as evidence of effectiveness. Ask what the clinic considers an acceptable threshold and what it would do if a preparation fell below it, since that answer reveals how the process is actually managed.
