context: When you have four or more migraines every month, your doctor may suggest you take a "preventive" medicine, instead of waiting to treat painful symptoms after they start. These drugs lower the chances that you'll have migraines in the first place. And when you do get one, it'll likely be briefer and less severe. Migraine affects everyone differently. Because of that, you may need to try more than one thing to find the treatment that's right for you. Your doctor will probably consider when and how often you get migraines and what other health problems you have. CGRP (calcitonin gene-related peptide) is a molecule involved in causing migraine pain. CGRP inhibitors are a new class of drugs that block the effects of CGRP. Erenumab ( Aimovig) are fremanezumab ( Ajovy) specifically approved to prevent migraine attacks. You give yourself an injection once a month with a pen-like device. In clinical trials, people consistently had one to two fewer migraine days a month than those who took placebo. Mild pain and redness at the injection site are the most common side effects. Some treatments for other health issues have been found to also stop migraines. For instance, beta-blockers, which doctors often prescribe to control blood pressure, can also slow down the brain cells linked to migraine. These include: Atenolol ( Tenormin) Metoprolol ( Lopressor, Toprol XL) Nadolol ( Corgard) Propranolol ( Inderal, Inderal LA, Inderal XL, Inno Pran) Timolol As many as 4 out of 5 of people who take beta-blockers get relief from their migraines. Still, like all drugs, they can cause side effects. These include feeling depressed and having problems during sex. You may not be able to take beta-blockers if you have asthma or diabetes. Your doctor may suggest a different type of preventive medicine if you have certain types of migraines with auras. These medicines were thought to increase stroke risk with this type of migraine, though the proof is very scant. Verapamil ( Calan, Covera, Verelan), which is often used to treat heart disease, may be a better choice for people who get auras. Calcium channel blockers are also often prescribed to treat cluster headaches. Unlike beta-blockers, you can take this medicine if you have asthma. Side effects can include constipation and low blood pressure. You don't need to be depressed to take them. They may be a good choice if you also have trouble sleeping. One type is known as "tricyclic antidepressants," or TCAs, these medicines affect certain chemicals in your brain that can set the stage for a migraine attack. Amitriptyline ( Elavil) Nortriptyline ( Aventyl, Pamelor) Some people gain weight and feel very tired when they take these. TCAs can also cause severe problems if you have heart disease or are pregnant. Venlafaxine is a different type of antidepressant called selective serotonin and norepinephrine reuptake inhibitors ( SNRIs). Experts say that is can also help prevent migraines. For kids and young adults, antidepressents could make depression worse and make suicide more likely. Tell your doctor right away. Long used to fill wrinkles, this nerve toxin has been found to stave off chronic migraines. It prevents a pain network in your brain from turning on. But it's only approved for people who have headaches at least 15 days each month. The more frequent your migraines, the better Botox seems to help. You may need several treatments before it starts to work. These drugs work by blocking pain signals in your brain. Divalproex sodium ( Depakote) Topiramate ( Qudexy XR, Trokendi XR, Topamax) Anti-seizure drugs could make you sleepy. You may also find it harder to focus. You shouldn't take them when you're pregnant. You should also avoid them if you have pancreatitis or a liver problem like hepatitis. If you're prone to migraines around your period, your doctor may have you take pain relief medicine like naproxen ( Anaprox, Naprosyn) or certain triptans, typically used to stop migraines once they've started, each month. You may be able to stave off an attack if you start a few days before your cycle starts, then stop a few days after your flow begins. Women who get auras with their menstrual migraines can take these instead of hormonal birth control, which comes with a greater chance of stroke for them. Doctors will often start with the beta-blocker propranolol, the antidepressant amitriptyline, or the anti-seizure medication topiramate. About half of people will have half the number of migraines once they're taking the right dose. For any of these drugs to work, you'll need to follow your doctor's instructions. In most cases, that will mean taking medicine regularly as prescribed by your doctor. It could be up to 3 months before you start to notice a difference. If you feel one drug isn't working, or comes with side effects that make you want to stop taking it, talk to your doctor. There may be a different treatment you could use that would be a better fit.