There's a unisex, accessible toilet on platform 1. This is the middle door in the second building from the front of the train. There's a push button on a short post to your left of the door as you face the building.
Note that this was not in use at the time of our survey. As has been the case for similar toilets on other stations, you may need to ask staff to activate the push button.
DUMBARTON CENTRAL STATION
© 2010, Terry Robinson