This study examines the relationship between the ex-ante real interest rate and economic activity in Russia, as well as tests the hypothesis of a structural change in this relationship following the adoption of the inflation targeting regime in 2014. The research employs the Generalized Method of Moments (GMM) to estimate various versions of the New Keynesian IS curve, which links aggregate demand to the real interest rate. The estimation of the selected IS curve specifications aims to evaluate the functionality of the interest rate transmission channel, whose mechanism relies on the ability of the key policy rate to influence aggregate demand through a chain of economic interconnections. The results indicate a persistent negative relationship between the real interest rate and economic activity in Russia over the entire observation period (2003–2023). Furthermore, the formulated hypothesis is not rejected, suggesting a strengthening of the link between the real interest rate and economic activity. This implies an increased capacity of the Bank of Russia to influence real economic indicators through its interest rate policy.