Lisa, there have been 2 trials of GSH in CF, 1 observational study, and there are now underway 2 other trials of GSH in CF. You can use PubMed to review those first 3 whose results have been published. No, isothiocyanate do not "release" trapped GSH; it strips the cells of GSH. There was an extended discussion of this on the wlgroup2, which is a yahoogroup. You can find the discussion in the archives of that group. Isothiocyanate is helpful in the extracellular milieu to fight bacteria.