Hydroxysafflor yellow A (HSYA), an active ingredient extracted from Carthami flos, shows potential for treating ischemic stroke. This phase 1 study assessed the safety, tolerability, and pharmacokinetic (PK) properties of HSYA in healthy Chinese volunteers who received intravenous infusions of pure HSYA powder. The study comprised 2 parts. Part A was a randomized, double-blind, placebo-controlled dose-escalation study that evaluated safety and tolerability. This included a single-dose study with 7 dose levels of HSYA (6.25, 12.5, 25, 50, 75, 100, and 125 mg) in 52 volunteers, and a multidose study (100 and 125 mg) in 16 volunteers. Part B was an open-label study where 12 volunteers received 75 mg of HSYA once daily for 14 consecutive days to examine PKs. There were no adverse events (AEs) leading to treatment discontinuation by HSYA throughout the treatment period. All reported AEs were mild and did not require special treatment. PK analysis revealed rapid absorption (median Tmax of 1.1 hours) and elimination (median t1/2 4.0 and 4.7 hours) of HSYA. Total body clearance on the 1st and 14th days was 1.7 and 1.6 L/h, respectively.