The peptide product, Valtyron, is obtained via enzymatic hydrolysis of sardine muscle. Although the safety and efficacy of the sardine peptide product have been evaluated in human studies, sardine peptides have not been identified as the subject of toxicological testing. In this study, the sardine peptide product did not exhibit any mutagenic activity in Salmonella typhimurium or Escherichia coli WP2uvrA. Likewise, the sardine peptide product was not associated with clastogenic properties in mouse bone marrow cells in a micronucleus assay. An oral rat LD(50) value of greater than 10,000 mg per kilogram of body weight was determined for peptide alpha-1000, and in rats administered peptide alpha-1000 by gavage at levels up to 5000 mg per kilogram of body weight per day for 28 days, no compound-related differences were observed in standard toxicological parameters. The results of these studies support the safety of the sardine peptide product for use in food for human consumption as a dietary source of peptides available from sardines.