Ginsenosides

Ginseng contains about thirty ginsenosides, which are triterpene glycosides, meaning a triterpene core with sugar groups attached [3]. Some, called rare ginsenosides (such as Rg3, Rh2 and compound K), occur naturally only in small amounts and are mostly produced when processing or gut metabolism removes sugar groups or changes the side chain [4].

Ginsenosides are heavily processed in the body. Most naturally occurring ginsenosides are deglycosylated by colon bacteria into intestinal metabolites [2], and only 0.2%–1.2% are excreted intact in urine [3]. This is why the ginsenosides listed on a label are not the only compounds of interest in absorption studies.

Not every product sold as "ginseng" contains them. Siberian ginseng contains eleutherosides, but not ginsenosides [3].

Ginseng extracts can be specified by ginsenoside content. Health Canada's Panax ginseng monograph, for example, lists extracts standardized to 4-7% total ginsenosides [5]. Two products with the same weight of ginseng can differ in ginsenoside content, so the extract and its standardization belong in any comparison between studies.

Product differences also make studies hard to compare. A review of ginseng interaction research found that preclinical results were largely inconclusive because studies used different ginseng products and methods [2]. When reading a ginseng trial, look for the species (Panax ginseng or another plant), the extract and its stated ginsenoside percentage.

For the graded evidence, see Panax ginseng.

• Standardized extract
• Adaptogen
• Cytochrome P450
• Bioavailability