All Energy Biomarkers We Test

Iron, Total

Total Iron Binding Capacity (TIBC)

Cortisol

Cortisol is the body’s primary stress-response hormone, made by the adrenal cortex and guided by the brain’s HPA axis. It mobilizes fuel, maintains blood pressure and vascular tone, tempers inflammation, and fol At home blood testing is available in select states. See FAQs below

Cortisol-to-DHEA-S Ratio

Cortisol-to-DHEA-S ratio blood testing compares two adrenal hormones in your bloodstream. Cortisol is the body’s primary stress hormone, made in the adrenal cortex’s middle layer (zona fasciculata) in response to adrenocorticotropic hormone (ACTH). DHEA-S is the stable, circulating form of DHEA (dehydroepiandrosterone sulfate), produced mainly in the inner layer (zona reticularis). At home blood testing is available in select states. See FAQs below

Ferritin

Ferritin blood testing measures ferritin—the body’s primary iron‑storage protein—in the circulation. Ferritin is made inside cells throughout the body, especially in the liver, spleen, and bone marrow, where iron is stored and recycled (hepatocytes and macrophages of the reticuloendothelial system). Its protein shell (apoferritin) holds iron safely in a mineral form (ferric iron). At home blood testing is available in select states. See FAQs below

Iron Saturation

Iron saturation is the share of your blood’s iron‑transport protein that is actually carrying iron at a given moment. In scientific terms, it is transferrin saturation (TSAT): the percentage of transferrin, a protein made by the liver, with its iron‑binding sites filled. At home blood testing is available in select states. See FAQs below

Iron, Total

Total Iron blood testing measures the amount of iron circulating in the liquid part of your blood, almost all of it carried by the transport protein transferrin. This circulating iron comes from two sources: iron absorbed from food in the small intestine and iron recycled from worn‑out red blood cells by cleanup cells in the spleen and liver (macrophages). At home blood testing is available in select states. See FAQs below

RDW / Ferritin Ratio

The RDW/Ferritin ratio is a combined blood index that relates red blood cell size variability (red cell distribution width, RDW) to the body’s iron reserves (serum ferritin). RDW comes from the standard blood count and describes how uniform or mixed in size your circulating red cells are (anisocytosis). At home blood testing is available in select states. See FAQs below

Total Iron Binding Capacity (TIBC)

Total iron binding capacity (TIBC) is a measure of how much iron your blood could carry if all of its transport slots were filled. It mainly reflects the amount of transferrin, the iron-transport protein made by the liver (transferrin, a glycoprotein produced by hepatocytes). At home blood testing is available in select states. See FAQs below