Re: cortsol saliva test unsuccessful

Was the sample you provided mainly saliva bubbles? This would cause a lot less saliva liquid to be available for testing.

It's worth asking the lab to be more specific about this.
It's also worth trying to submit another sample. Do not drink before taking the sample. Try to produce liquid saliva, not bubbles of saliva.

Serum cortisol levels are useful and the 'free' levels of cortisol available can be worked out from a serum sample.