T89 (Dantonic) is a modern herbal medicine currently used in Chinese hospitals for the management of ischemic heart disease. This dose-escalation clinical trial aims to assess tolerability of Western people to T89. Healthy Australian adults of non-Asian background orally took a single dosage of 6, 8, 10, 12, 13, 14, 15, or 16 T89 capsules (6 people for each dose) and were assessed with respect to symptoms and physical signs, electrocardiogram, hematology, plasma biochemistry, and urinalysis. Secondary objectives were to determine the dose-limiting toxicity and maximum-tolerated dose. It found that a single dose of T89 up to 16 capsules was not associated with significant adverse events or abnormalities in clinical laboratory tests and electrocardiogram parameters, except minor symptoms reported included mild and transient dizziness, stomach discomfort, diarrhea, and involuntary muscular contraction. The incident rate of these symptoms was generally low (1/30, 3.3 ) but increased (7/18, 38.9 ) in higher dose ( 14 capsules) groups. No defined dose-limiting toxicity events occurred; so the study could not define the maximum-tolerated dose. In conclusion, a single dose of T89 up to 13 capsules, 4 times of a regular therapeutic dosage, is generally safe and tolerated by individuals of non-Asian background.