Over the counter medicine that is in pill form can be brought onto the plane in unlimited quantities.
But if the medicine is in liquid form and is not medically necessary then you to follow the container size rule and have it in sealed bags and are limited to the amount of liquid carry on medicine that the airline limits.
The liquid medicine must stick to the 3-1-1 rule and must be in containers less than 3.4 ounces or packed in your checked baggage.