During fasting, the liver engages several mechanisms to facilitate hepatic glucose production. Recent studies have identified post-transcriptional regulators of liver function including non-coding RNAs and inhibition of abundant microRNAs. Yan, Wang, Bishop, et al. show that Argonaute2 (Ago2) expression in the liver is modulated according to changes in extracellular glucose concentrations and conditional deletion in the hepatocyte diminishes adaptive glucose production during fasting. Together these results identify Ago2 as an essential regulator of the fasting response.