Frequency drift from EPI-based sequences prior to MRS scans is a known issue. Running MRS scans ‘from cold’ is suggested for the greatest scanner stability, with some equilibration period for systems with overnight energy-saving mode. Running MRS scans before scanner reaches an equilibration period can result in large frequency drifts. Under these conditions, the effect of running fMRI scans seem to be negligible. Applying frequency and phase correction can make the final spectrum appear to be qualitatively similar between scans with big and negligible drift.