Synephrine (SP)

Synephrine is an alkaloid, occurring naturally in some plants and animals, as well as in approved drugs products in form of its m-substituted analog known as neo-synephrine. p-synephrine m-synephrine are known for their longer acting adrenergic effects compared to norepinephrine. This substance is present at very low concentrations in common foodstuffs such as orange juice and other orange (Citrus species) products, both of the "sweet" and "bitter" variety. While the traditional preparations have been in use for millennia as a component of TCM-formulas, synephrine itself is not an approved OTC drug. As a pharmaceutical, m-synephrine is still used as a sympathomimetic (i.e. for its hypertensive and vasoconstrictor properties), mostly as a parenteral drug in the treatment of emergencies such as shock and rarely p.o. for the treatment of bronchial problems associated with asthma and hay-fever.