You can bring your medication in pill or solid form in unlimited amounts as long as it is screened. You may bring medically necessary liquids, medications and creams in excess of 3.4 ounces or 100 milliliters in your carry-on bag.A rule of thumb: Bring no more than a 90day supply of medication. Most medications are allowed on planes. There are some exceptions to flying with medication, which we'll cover below. While you're allowed to bring your prescription medications with you on a flight, it's important to have some sort of documentation with you. Allergy medications. • Muscle relaxants. You will be able to take prescription medicine with you on board with no problem. Traveling With Medications.