Nutraceutical and dietary supplement formulations for delivering bioavailable thiols to a host, comprising certain organosulfur radicals, such as the allyl mercapto radical, bound to larger molecules such as proteins, resulting in the formation in the host's body of various allium-related compounds such as allicin. The formulations are produced by treating an ingestible material comprising a cysteine-containing protein with a thiol, disulfide, mixed disulfide, thiosufinate or mixed thiosulfinate so as to cause thiol residues to become disulfide bonded to cysteines contained in the protein.