It is difficult to monitor what we do not measure.
All steroid hormones (progesterone, estrogen, DHEA, cortisol, and testosterone) are fat soluble. This means that they dissolve in fat or oil and not water. As oil and water do not mix, the body makes a water-soluble carrier proteins (can dissolve in water) to attach to the fat soluble hormones and allow them to travel in the watery bloodstream to their target tissues. But because they are surrounded by a water-soluble carrier protein, these bound hormones cannot enter the cells. So, even though they’re present, they are unable to have an effect on tissues. More than 99% of steroid hormones in the blood are bound to a carrier protein. Blood (serum) testing measures these carrier-bound hormones and does not reflect the levels of active unbound hormones. The remaining 1% of steroid hormones are unbound or free and this is the form which exerts activity on tissues. These free, unbound, active hormones are measured in saliva.
- Is extremely sensitive and measures the very small concentrations of free hormone
- Free hormones in saliva represents the quantity of hormone available in target tissues
- Free hormone levels in saliva correlate to symptoms of hormone excess or deficiency
- Can measure transdermally (through the skin) delivered hormones– levels that are too small to be measured in the serum
Serum (Blood) Testing:
- Cannot easily distinguish between bound and free hormone ( problematic because only the free hormone is clinically significant)
- Has a large normal range for hormones
- Provides limited clinically useful information when following levels of transdermally applied steroid hormones
Saliva testing is the most accurate way to determine steroid hormone levels when using transdermal application because it measures the small amounts of free (unbound) or bio-active hormone. It is much more precise and useful than blood testing which is why we use saliva as a means of measurement at the Randali Centre.