THK-523 has shown selectivity and high affinity for tau pathology both in vitro and in vivo. 18 F-THK523 is a potent tau imaging radiotracer which is a potent in vivo tau imaging ligand for Alzheimer's disease [1].

THK-523 effectively penetrates the blood-brain barrier in mice, demonstrating an increased in vivo retention rate in the brains of Tau transgenic mice [1]. In this animal model, utilizing tau transgenic mice [1], the compound was administered intravenously at a dosage of 0.35 μg/kg, with observations made 25-30 minutes post-administration. The result noted was an overexpression of Tau in the brain.