@cherryrosh,
Drano for instance jumps to mind but of course Cher many drain cleaners are available. I've used such in combination with plunger. I use the cleaner first, according to the theory that if it's apparently unsuccessful then at least it loosens the clog; then later the plunger
The temptation is to plunge vigorously. In the rare case however, downstroke actually forces a pipe junction apart. So best bet might be, plunge most gently but then withdraw with utmost force