On Mac OS X only, you can add Audio Unit plug-ins to the system plug-in directories (Audacity will not recognize any Audio Units in its own “plug-ins” folder).

The VST Plug-ins page on the Audacity Wiki contains further help for VST plug-ins, and lists a large number of VST plug-ins that have been reported to work well in Audacity. VST effects can be found on many plug-in sites such as: Then use the Plug-ins Manager to enable the new plug-ins as in the plug-in installation instructions above. Install the VST effects to the Audacity Plug-Ins folder on Windows, to ~/Library/Application Support/audacity/Plug-Ins on OS X/macOS or to system locations. Audacity can load VST effects (but not VST instruments) on all operating systems.