An oral formulation of arginine .alpha.-ketoglutarate is disclosed which formulation is comprised of arginine .alpha.-ketoglutarate and one or more excipient materials. A wide range of different controlled release formulations will be apparent to those skilled in the art upon reading this disclosure. The formulation of arginine .alpha.-ketoglutarate and excipient material is designed to obtain a desired result, e.g. attenuate symptoms suffered by a patient with a glutamate dehydrogenase deficiency or increase prolyl hydroxylase and lysyl hydroxylase activity or prevent protein glycation characteristic of atheroscloerosis, cataract formation, retinopathy, and aging. The desired results are obtained by increasing the period of time that a therapeutic level of arginine .alpha.-ketoglutarate is continuously maintained in the patient. The therapeutic level as well as the period of time over which that level must be maintained can vary between patient based on a range of factors such as the condition of the patient and the patient's reactivity to arginine .alpha.-ketoglutarate. However, the period of time will be greater than that obtained with a conventional quick release arginine .alpha.-ketoglutarate formulation.