Natural products play a crucial role in drug discovery, primarily due to their structural complexity. The prenylated flavanone, glabranin ((S)-5,7-dihydroxy-8-(3-methylbut-2-en-1-yl)-2-phenylchroman-4-one), isolated plant Dalea elegans, has demonstrated neuroprotective effects, attributed to its inhibition of GSK-3β as per our previous in silico studies. Given the enzyme's diverse functions and its potential as a target for neurodegenerative diseases, our group synthesized and evaluated an 11C-labeled derivative of glabranin. We present its in vitro biological activity, including IC50, neuronal uptake in Alzheimer’s-affected brain regions, key physicochemical properties, and animal studies. This study confirms [11C]FLA's interaction with GSK-3β in vitro, highlighting the potential of radiotracers in bioactive compound research.