Change your preferences here.
Deals damage. If the target Pokemon is poisoned, the move's Base Power doubles.
Venoshock is an extremely situational move; it only has a reasonable Base Power as long as the opponent is poisoned. The problem is you need to make a team around it, meaning it's typically not the best of ideas. In order to make it work, Toxic Spikes needs to be on the opposing side of the field in order to reliably poison a majority of the opposing team's Pokemon. Too much work, too little results. If you are looking for a STAB Poison move to use, there are better options.
Sludge Bomb is a more reliable alternative, but it has lower Base Power when the opponent is poisoned.