Nulgrind is the minimal tool for Valgrind. It does no initialisation or finalisation, and adds no instrumentation to the program's code. It is mainly of use for Valgrind's developers for debugging and regression testing.

Nonetheless you can run programs with Nulgrind. They will run roughly 5 times more slowly than normal, for no useful effect. Note that you need to use the option --tool=none to run Nulgrind (ie. not --tool=nulgrind).