How Does Saliva Compare?

Hormone Testing Mediums: Strengths and Weaknesses

Hormone measurements are used for a variety of clinical interpretations including the assessment of hypothalamic-pituitary-adrenal (HPA) axis function and evaluating male and female sex hormones. Hormones – such as cortisol, melatonin, testosterone and progesterone – can be tested using saliva, blood, and wet urine (with fingernail and hair analysis coming on strong for cortisol).

A patient’s clinical care depends on the accuracy and reliability of the laboratory data and health professionals need to be wary of using inappropriate methods. In the following papers, we review the key differences between the use of saliva, serum, wet urine, and dried urine specimens for the laboratory assessment of hormones.

Summary Comparison of Common Sample Type

Criteria Saliva Wet Urine Blood Dried Urine
Peer reviewed studies to support testing of hormones Yes Yes Yes No
Assay validation criteria met Yes Yes Yes Maybe*
Clinical applications supported by research Yes Yes Yes No
Stability of analytes demonstrated Yes Yes Yes No
Ability to test free, bioactive hormones Yes Yes Yes Yes
Measures total hormones load over 24 h No Yes No No
Convenient collection Yes No No Yes**
Measures real-time hormones levels Yes No Yes No

*While the other sample types are well-established globaly with common validations, dried urine’s validations remain unavailable given their LTD status.

**Urinating on paper may be convenient, however the quality of the paper and risk of contamination while the sample is drying are of concern, as explained in the text

Peer reviewed literature to support hormone testing in different sample types

Criteria Saliva Wet Urine Blood Dried Urine
Free diurnal rhythm of Cortisol > 1000 citations 2 citations by same group Not feasible 0
Measurement of Cortisol Awakening Response > 450 citations Not feasible Not feasible 0
Melatonin for DLMO patterns > 75 citations Not feasible ~ 39 citations 0
Relevant clinical applications of free cortisol > 900 citations > 800 citations > 5600 citations 0
Relevant clinical applications of hormone metabolites Not feasible 80 citations > 100 citations 0