This study aimed to determine the maximum tolerated dose and safety profile of a standardized curcumin powder extract (C³ Complex™, Sabinsa Corporation) in healthy volunteers. A dose escalation study was conducted, with subjects receiving escalating doses from 500 to 12,000 mg. Seven out of twenty-four subjects experienced minimal toxicity, which did not appear to be dose-related. No curcumin was detected in the serum of subjects administered doses up to 8,000 mg, while low levels were detected in two subjects at 10,000 and 12,000 mg. The study concluded that curcumin appears to be well-tolerated in high single oral doses, warranting further investigation as a potential long-term chemopreventive agent for colorectal cancer. However, the poor bioavailability of curcumin and the need for higher doses to overcome intestinal metabolism are important considerations.This study aimed to determine the maximum tolerated dose and safety profile of a standardized curcumin powder extract (C³ Complex™, Sabinsa Corporation) in healthy volunteers. A dose escalation study was conducted, with subjects receiving escalating doses from 500 to 12,000 mg. Seven out of twenty-four subjects experienced minimal toxicity, which did not appear to be dose-related. No curcumin was detected in the serum of subjects administered doses up to 8,000 mg, while low levels were detected in two subjects at 10,000 and 12,000 mg. The study concluded that curcumin appears to be well-tolerated in high single oral doses, warranting further investigation as a potential long-term chemopreventive agent for colorectal cancer. However, the poor bioavailability of curcumin and the need for higher doses to overcome intestinal metabolism are important considerations.