My suggestion is it's always best to see a medical professional unless this is a common issue for you. This is especially important if the wart is in an sensitive or cosmetically important area- face, genitals, sole of feet, palms, finger/toenails.
These are the common OTC treatments
- Salicylic Acid, available in various forms- gels, patches, etc
- Cryotherapy - OTC freeze off product
- Taping, which involves putting duck tape on the wart and changing the tape every day. The adhesive may gradually peel away layers of the wart.
It's also worth noting these methods should not be used over a widespread area (i.e. You had clusters of warts).
There are some other options you could discuss with your doctor such as lasers, more sophisticated cryotherapy, and various prescription meds depending on your situation.