Evaluating Chronic Allostatic Load Through Salivary Cortisol Awakening Measurements
Salivary cortisol awakening curves reveal chronic allostatic wear by tracking whether morning adrenocortical activation surges adaptively or flattens under load.
free steroid fraction
Meaning
Blood analysis reveals the portion of a hormone that is actually available to act on tissues. The free steroid fraction refers to the small percentage of cortisol or testosterone not bound to carrier proteins in the blood. Only these unbound molecules can enter cells to trigger a physiological change.
This measure provides a more accurate view of systemic load than total hormone levels alone.
Bioavailable Content
Protein binding acts as a reservoir for the endocrine system. A high free steroid fraction means more of the hormone is hitting the receptors in the brain and muscles immediately. This increases the intensity of the physical and psychological response to pressure.
Regulatory Threshold
Carriers prevent the body from being overwhelmed by its own signals. When the free steroid fraction rises too high, the risk of tissue damage and neurotoxicity increases. The liver must work harder to produce the proteins that keep these hormones in check.
Distribution Efficiency
Delivery of chemical messages depends on the balance between bound and unbound states. A low free steroid fraction might suggest that the body is trying to protect itself from overstimulation. This state limits the speed at which a person can react to a new operational challenge.