This Product cannot be purchased without a prescription
FRONTLINE Combo is the prescription-only form of FRONTLINE Spot On, the most popular Flea and Tick treatment available. Combo has an extra ingredient which is particularly helpful for flea control if you forget to re-apply FRONTLINE as frequently as you should. The extra ingredient has a more persistent action on the skin and coat of dogs and cats.
This additional ingredient does not kill fleas, but in effect it sterilizes female fleas so that they cannot breed. Each individual flea does not live for long anyway, so that preventing them breeding can be an effective form of control in itself.