Preventive medications are taken daily for several months to reduce the frequency and intensity of migraines. Should you try one? Here are some common questions and answers about migraine preventives! 

How do I know if I need a preventive medication?  

There is no absolute rule. The impact of migraines on your life is the main factor. Generally, when people have more than 4-6 migraines per month, the impact is significant enough to consider prevention. Still, making changes to your lifestyle can be a first option. If you are having more than 10 days of migraine per month, the risk of becoming chronic is high and a preventive should be prescribed. Anybody with chronic migraine (>15 days per month) should try preventive.

Will my doctor decide if I should take a preventive medication? 

The decision to take a preventive treatment is yours. Discuss the pros and cons with your doctor. Setting clear expectations and having a plan you’re comfortable with is key. 

What is the effect of preventive medications on my brain? How do they decrease migraines? 

Several types of preventive medications exist and act through different mechanisms in the brain. It is thought that they increase the migraine threshold (the limit your brain has for migraine occurrence) and make the brain less susceptible to triggers. 

I have been prescribed a drug for depression/blood pressure but I am not depressed/my blood pressure is normal. Why is that? 

Older migraine preventives have not been designed for migraine. Often, their effect on migraine has been observed by people who were taking them for other reasons. Remember that medications may have different effects on the brain and body. For example, blood pressure drugs also have effects on brain networks. 

Are preventive medications dangerous? 

All preventive medications have possible side effects and risks. Some people should not take some of these medications for medical reasons, it is up to your doctor to check which treatment is best for you. 

How will I know if my preventive medication works

Before starting a preventive medication, you need to know what your baseline migraine frequency is. Keep a Headache Diary! (See this post)

What can I expect as a benefit? 

Ultimately, the idea is to decrease the impact of migraine on your life. 

There are two types of improvement: on frequency and on severity. 

  • A preventive treatment decreases migraine frequency by 50% in 50% of patients who try it. Some people may have a «super response» to some medications (75% better). 
  • Severity can also decrease: you may have less nausea, your acute treatments may work better, you may be able to miss work or activities less often. 

Other signs of improvement can include:

  • Less sensitivity to triggers
  • Better effect of acute medications
  • More ability to plan activities
  • Better mood and sleep

What is the best migraine preventive? 

Remember the Golden Rule: NO ONE SIZE FITS ALL. People with migraine have different brains and different bodies. At present time, no one can predict who will improve with a certain medication or not. Trying different options is key.

What side effects can I expect? 

Each medication has possible side effects (Preventive table). Not everyone trying a medication will have side effects! Most often side effects are mild and decrease over time. It is important to note that side effects often occur quickly but it may take longer to see a benefit from the preventive medication. «Side effects come first, benefit is seen later». 

Are there dangerous side effects?

Serious side effects are rare but can occur. Your physician should tell you about serious side effects. Your pharmacist can also help. Seek help quickly if you observe a worrisome symptom. 

Will the medication make me gain weight? 

Some preventives are associated with weight gain, others with weight loss, and many are weight neutral. Not everyone who takes a medication with an associated side effect manifests it. If you do start a preventive that can cause weight gain, monitor your weight and monitor your diet. 

How long do I have to try the medication?

In order to be effective, a preventive medication must be taken at high enough doses for a long enough time. For oral preventivies (except gepants), it usually takes a month to titrate up on the dose and 2-3 months on the effective dose for each trial. One month is never enough to make a decision. For Botox, at least 2 cycles (3 months apart) is recommended. For CGPR antibodies, even though some people improve right away, a trial period can be between 3 and 6 months.

Will I become addicted to my medication? Should I take it for life? 

Preventive medications do not cause addiction (opioids and cannabinoids do). If they work, you will want to continue them, but it is not a question of addiction. A diabetic is not addicted to insulin! If the medication is effective, it is continued for at least a year before reducing the dose. Never stop medications abruptly, this could trigger intense migraine attacks.

Now do you want to see your options? Have a look at our Preventive Table!


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VanderPluym J, Evans RW, Starling AJ. Long-Term Use and Safety of Migraine Preventive Medications. Headache. 2016;56(8):1335-43.

Tepper SJ. History and Review of anti-Calcitonin Gene-Related Peptide (CGRP) Therapies: FromTranslational Research to Treatment.Headache. 2018;58 Suppl 3:238-75.

Argyriou AA, Mantovani E, MitsikostasDD, Vikelis M, Tamburin S. A systematic review with expert opinion on the role of gepants for the preventive and abortive treatment of migraine.Expert Rev Neurother. 2022;22(6):469-88.


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