Oligonol((R)) is an optimised phenolic product containing catechin-type monomers and lower oligomers of proanthocyanidin that emanate from a technology process which converts polyphenol polymers into oligomers. In a single dose toxicity study administration of Oligonol (2000mg/kg bw) by gavage for 4 weeks was found to be safe with no side effects (such as abnormal behavior and alopecia). Body weight gain and food consumption were within normal range. Oligonol had no observed toxicity at the dose (1/25 of LD(50)) administered for 6 months. This suggests that Oligonol is safe at repeated human intakes of Oligonol in doses lower than 200mg/day. The highest dose used in this study is equal to 12g daily for an adult man with 60kg body weight. The LD(50) was calculated to be 5.0g/kg body weight (95% confidence limit: 3.5-6.4g/kg). Studies conducted on 30 healthy volunteers consuming Oligonol at doses of 100mg/day and 200mg/day for 92 days showed good bioavailability. The biochemical parameters attesting to liver and kidney functions as well as the hematological parameters were within the normal ranges. The potential of Oligonol to induce gene mutation (a reverse mutation test) was tested using Salmonella typhimurium TA98, TA100, TA104, TA1535, TA153 and Escherichia coli WP2uvrA. Oligonol was not mutagenic to the tester strains. The lack of toxicity supports the potential use of Oligonol as a food or dietary supplement and for use as an additive in pharmaceutical and cosmetological applications.