Flying to Portugal in a couple months and steroids in personal quantities are not illegal there, even without prescription, actually it's also legal to import steroids into the country in personal quantities.
So therefore when crosssing customs at Pearson it's like crossing through the Portugese border, where they would allow it.
No biggie either way because it's easy to buy there, but I would prefer to bring my own gear and don't want to break any laws as a responsible adult.
Only thing I can think is that border patrol might decide to be dicks and confiscate them, but that doesn't sound reasonable if no laws are being broken.