Depending on the leak, it will, if you put too much of it in though it can start to clog up ports.
Especially your water pump ports.
Long time ago I bought a datsun and the guy who owned it was pouring stop leak in for days trying to stop a head gasket leak, it didn't fix it so I replaced the head gasket and it was a good car for 2 years no problem, then it started to overheat, the problem was the water pump ports were clogged with stop leak.
It took 2 years from the time he stopped pouring stop leak in for the stop leak to plug the ports.
This is even 2 years after I changed the head gasket, so even replacing the coolant didn't get rid of it all.


