The Power of Saliva

Close-Up of Baby's Lower Face with Saliva Dripping from the Side of the Mouth.

Saliva. Watery, mostly clear, helps with food digestion. What does it have to do with stress? And more importantly, how could it possibly measure anything in the rest of your body?

Saliva is about 99% water. The remaining 1%, as always, holds so much power. It is full of enzymes and immune substances, and lo and behold, it also filters through some hormones. Specifically the steroid hormones cortisol, progesterone, the three estrogen forms, testosterone and Dihydrotestosterone. 

What’s the benefit of salivary testing?
When we get a lab test of our blood (serum) for any of these hormones, it measures hormones that are bound to their carrier protein (aka, out of service hormones). While this measurement can be incredibly helpful for diagnosing an extreme deficiency or excess, it cannot accurately depict how those hormones are being used in the body. Because carrier proteins do not pass through into the saliva, when we measure salivary hormones it represents the hormone at the cellular level - the amount that is actively available for use. 
If you want to understand how any of the steroid hormones are affecting your health, the unbound, bioavailable, active hormone levels are much more useful.
We like to describe it as if your hormones have a chaperone. It’s only when they can shake off their chaperone can they get anything done. If you want to know what that hormone is really doing, the chaperoned version (aka in blood form) is unlikely to offer us any valuable information.

How do we know that it is a reliable test?
Even though many tests can be run from a saliva sample (DNA, Rapid Antigen or Antibody Tests, PCR - words we have become too familiar with), not all biomarkers can be measured in saliva with confidence. Steroid hormones move passively from blood into saliva, which means the amount of saliva you make or how fast you produce saliva doesn’t affect the concentration of hormone in the collection tube. Certain other biomarkers, even though they may be found in saliva, are what’s called flow dependent - meaning they pass through various channels before getting to the saliva and the concentration found in a sample would vary based on flow and channel.
At hey freya, we are precise and specific. We focus on the best hormones that your saliva can offer.

Why doesn’t my doc use it? 

Here’s the thing… 

In clinical diagnostics of hormonal disease, saliva is not considered standard, since disease is often classified by severe excess and deficiency, not descriptive daily functional patterns. But in clinical research, saliva has been used for decades to assess hormone status. What’s the difference? It’s what’s called the 17 year lag. Since salivary testing is not a diagnostic test and the lag is still catching up, the standard of care has yet to readily accept it. 
Just because it is not widespread clinically, does not mean the evidence is lacking. Check out our favorite researchers, Katrina Hamilton, Robert-Paul Juster and others that co-author along with them. They are doing the hard work of validating and discovering the impact of stress on health using salivary methods, and in particular consider gender and sex differentiation. We applaud them and we think you should too. They are the folks who are closing this 17 year gap.
Also, when it comes to getting validation of stress by the standard of care, we think that’s a bit like your healthcare system micromanaging your lifestyle.

Perhaps, as long your path to body literacy is safe, informed and working for you, your physician doesn’t need to approve of how you take care of yourself. Taking your body back can start with having access to non-disease biomarkers at home. If you can track steps, sleep and heart rate at home, why shouldn’t you be able to test your cortisol levels?

Get our Stress Test today and see how investing in your body literacy will make a world of a difference in your well-being. 


Human saliva as a diagnostic specimen
An often forgotten but convenient diagnostic fluid
The 17 year lag from research to practice
Crossing the Quality Chasm: A New Health System for the 21st Century

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