Branch Chain Amino Acids (BCAA) have recently been implicated in Alzheimer’s Disease (AD). We previously showed that low dose brain radiation (RT) [5 fractions of 2 Gy] reduces amyloid-beta plaque burden and results in improved cognition in the APP/PS1 model of AD. In this study we investigated whether this schedule of radiation altered the metabolomic profile of serum. 10 month old male (M) and female (F) APP/PS1 mice were either treated with whole brain radiotherapy (5 x 2 Gy) or received sham irradiation.