A South American tree and source of “Quebracho” – a traditional herbal remedy for erectile dysfunction.  Quebracho is an alternate source of yohimbine, although it’s unclear if other compounds are present that could contribute to its reputed effects.

See Salicin.

See Salicin.

A natural anti-inflammatory compound derived from white willow bark (Salix alba).  Salicin is chemically similar to aspirin, and has a similar action.

White willow bark extracts standardized for salicin were typically added to ephedra-based fat burners designed to be “all natural” versions of the well-known ”ECA” stack (ephedrine, caffeine, aspririn – see Paul’s Xenadrine RFA review for one example).  Theoretically, aspirin/salicin works synergistically with ephedrine/caffeine to enhance lipolysis, but there is less research to back this up (and the “EC” stack is quite effective without it). 

Salicin-containing extracts are also added to “ephedra-free” fat burners, but there is no evidence it provides any benefits.

See Citrus aurantium.

Commonly referred to as “Bitter Orange,” but may also be known as “Seville Orange” or ”Zhi shi.”  Citrus aurantium has been used in traditional medicine as a decongestant and treatment for nausea/indigestion.  Bitter orange contains a range of phyisiologically active biogenic amines: tyramine, methyltyramine, octopamine and synephrine.

Standardized extracts of Citrus aurantium are commonly used in “ephedra-free” fat loss supplements.

See Paul’s review, “Synephrine, Citrus Aurantium, Advantra Z™: Potent Fat Burner, Or Total Dud?” for more information.

A proprietary Citrus aurantium extract made by Nutratech, Inc that’s standardized for synephrine.

See Paul’s review, “Synephrine, Citrus Aurantium, Advantra Z™: Potent Fat Burner, Or Total Dud?” for more information.

A sympathomimetic compound derived from Citrus aurantium (”bitter orange”).  Synephrine is chemically related to ephedrine, and used as a substitute in “ephedra-free” fat burners.  It’s been claimed that synephrine is as effective as ephedrine, while producing fewer side effects, but the evidence for this is slim.  Synephrine appears to be mildly effective for weight loss, but – as Paul notes in his review “there is no evidence to support dramatic results.”

Synephrine is sometimes confused with “Neo-Synephrine” (aka phenylephrine) – an isomer with different pharmacologic properties.

See Paul’s review, “Synephrine, Citrus Aurantium, Advantra Z™: Potent Fat Burner, Or Total Dud?” for more information.

See Di-Arginine Malate.

A delivery form of L-arginine used in certain NO (nitric oxide) boosting bodybuilding supplements. “Ethyl ester technology” is claimed to enhance absorption and utilization, but there is no proof that this is true; or that arginine ethyl ester HCl is more effective than straight L-arginine, let alone traditional delivery forms such as AAKG.