Protodioscin

Protodioscin is a natural steroidal saponin, a glycoside of a steroidal sapogenin, most notably found in Tribulus terrestris. In plant chemistry it is classified as a furostanol (and related spirostanol) glycoside and is often cited as one of the major saponins in Tribulus extracts. When hydrolyzed, protodioscin yields the aglycone protodiosgenin and sugar residues; the compound is used as a chemical marker for quality control of Tribulus preparations.

Occurrence and production: Protodioscin occurs in Tribulus terrestris and related species, with content that varies by cultivar, geography, harvest, processing, and extraction method. Commercial extracts may be standardized to saponin content, and sometimes to protodioscin content, though values vary widely.

Biological activity: Some animal studies report effects on androgen-related endpoints, while human studies provide limited and inconsistent evidence for increases in testosterone or improvements in libido or athletic performance. Overall, robust proof of clinically meaningful benefits in healthy individuals is lacking.

Safety and regulation: Protodioscin-containing supplements are generally well tolerated at typical doses, but saponins can cause gastrointestinal upset in some individuals. Long-term safety data are limited, and claims of hormonal enhancement remain unproven. Regulatory status varies by country; protodioscin is not approved as a drug and is primarily a constituent of dietary supplement products.