Products that contain GBL are marketed for many claimed purposes, including to induce sleep, release growth hormones, enhance sexual activity and athletic performance, relieve depression, and prolong life. GBL is converted by the body into gamma-hydroxybutyrate (GHB), a drug banned outside of clinical trials approved by the Food and Drug Administration. Recognized manifestations of GHB toxicity include bradycardia, hypothermia, central nervous system depression, and uncontrolled movements. This report describes seven cases of GBL toxicity in Minnesota that involved the product "Revivarant," which is labeled as containing 1.82 g of GBL per fluid ounce. The cases were reported from two hospital emergency departments during October-December 1998. The report also summarizes an additional 34 cases of GBL toxicity reported to poison centers in new Mexico and Texas during October 1998-January 1999. GBL is an industrial and household solvent of acrylate polymers, and unintentional poisonings have been reported. It is also marketed as a dietary supplement at health food stores and on the Internet under several trade names. Although labeled as dietary supplements, GBL-containing products are illegally marketed. On January 21, 1999, the Food and Drug Administration asked manufacturers to recall their GBL-containing products and warned consumers through press releases to avoid taking these products. 10 references