How bad of a leak, and how far are you going?
Any kind off stop leak works, but to much of it
is not good for the system. Heater core, thermo
stat, water pump will fail or plug up if you use
to much.

Open the cap one notch and bring extra water with
you. You might just make it where you are going, if it's a pin hole leak.
Then fix it without stop leak.