MAOIs, or monoamine oxidase inhibitors, are a class of depression medications. MAOIs work by stopping serotonin, dopamine, epinephrine, and norepinephrine from being removed from the brain. This action encourages the circulation of these neurotransmitters, which are believed to be low in some people with depression.

MAOIs work by inhibiting an enzyme called monoamine oxidase. This enzyme breaks down dopamine, serotonin, epinephrine, and norepinephrine. MAOIs were the first class of drugs to decrease MAO to treat depression.

MAOI and Tyramine

In addition to breaking down neurotransmitters, MAO also breaks down tyramine in the body. So if you take an MAO inhibitor, you treat depression symptoms, but you also prevent your body from breaking down tyramine efficiently.

People who take MAOIs need to restrict the amount of tyramine they eat to avoid dangerous episodes with high blood pressure.

However, tyramine is abundant in quite a few foods: most cheeses, chocolate, citrus, tomatoes, bananas, and anything fermented, to start. It’s not an easy dietary amine to avoid.


Serotonin reuptake inhibitors (SSRIs) work by stopping the reuptake of serotonin in the brain. This action allows the amount of serotonin in the brain to increase. It’s a similar result but a different mechanism of action from an MAOI.