glycyrrhizin

The name is the whole description. Glycyrrhiza glabra takes it from the Greek glykys, sweet, and rhiza, root, and glycyrrhizin is that sweetness given a formula: a molecule the plant has carried under roughly the same name for about two and a half thousand years, since Dioscorides gave licorice a full entry in the first century. In this library it appears in four teas, always traced to licorice root: a period-support blend, a gas-relief tea, a nausea-and-reflux tea, and a sweet digestive tea, each rounded by a sweetness that needs no added sugar.

Glycyrrhizin, C₄₂H₆₂O₁₆ at 822.94 daltons, is nothing like sugar structurally. It is a triterpenoid saponin, a five-ring steroid-like skeleton called glycyrrhetinic acid with two glucuronic acid sugars hung off it, and the European Commission's own dossier puts its sweetness at 33 to 200 times sucrose depending on how it is measured, a wide range that reflects how the sweetness arrives late on the tongue and leaves slowly rather than tracking sugar's own scale. Swallowed, the molecule barely survives intact: gut bacteria strip both sugars off, leaving glycyrrhetinic acid, which is what actually gets absorbed and recirculated through the liver.

That absorbed fragment does something sugar never does. The kidney's aldosterone receptor cannot tell aldosterone from cortisol, and an enzyme normally converts cortisol to an inert form before it reaches that receptor. Glycyrrhetinic acid disables the enzyme, so cortisol gets through and the body responds as if flooded with aldosterone: sodium and water retained, potassium lost, blood pressure raised. Regulators could not derive a proper safe daily dose at all and settled for a ceiling of 100 milligrams a day from every source combined; a Dutch survey of thirty-three herbal tea brands found some brewing up to 450 milligrams per liter, over four times that ceiling in a single pot. This library's four recipes keep it as a rounding note rather than a base, one of them capped at half a teaspoon on purpose.