Serotonin is a chemical messenger that affects many functions within the body and brain. One theory is that serotonin helps regulate anxiety and stress. Low serotonin is one of the factors that may contribute to depression, but people can take some steps to increase their serotonin levels.

The body makes serotonin naturally, but there are some ways to increase its production. For example, certain medications, dietary factors, and exercise might promote increased serotonin levels.

In people who are not experiencing depression, it is unclear whether increasing serotonin will be beneficial. However, for those who are, some may find that addressing serotonin deficiencies could help with symptoms.

Keep reading to learn more about serotonin, some scientifically proven ways of increasing its levels, and some possible risks of doing so.

What is serotonin?

Increasing serotonin levels, such as through exposure to light, may help mitigate the risk of depression or reduce symptoms in people experiencing this condition.

Serotonin is a chemical found throughout the body. It plays an important role in regulating a range of bodily functions, including blood clotting and bowel function.

The body combines tryptophan with an enzyme to make serotonin. While other areas of the body produce serotonin, the chemical is most common in the brain.

In the brain, serotonin performs the role of a neurotransmitter. Neurotransmitters are chemicals that relay messages around the brain to support its functioning.

There are many theories about the role of serotonin in the brain. A widespread idea is that serotonin contributes to brain networks that regulate stress and anxiety. The chemical may also promote patience and the ability to cope.

Serotonin appears to play a role in several mental health conditions, including depression and anxiety disorders. Several common antidepressant medications increase serotonin levels as a way of treating depression.

How to increase serotonin levels

There are many products that manufacturers claim can boost serotonin levels and improve mood or help with stress. However, there is a lack of evidence behind many of these claims.

The following factors have scientific evidence to support them:

1. Medications

Several common antidepressant medications directly increase serotonin levels in the brain.

Selective serotonin reuptake inhibitors (SSRIs) are a class of antidepressant medication that prevents serotonin from reabsorption in the brain. By doing this, these drugs increase the levels of serotonin available to receptors.

Examples of SSRIs include fluoxetine (Prozac) and sertraline (Zoloft). These drugs are effective for increasing serotonin and can treat symptoms of depression.

2. Exercise

Exercise has a substantial effect on the brain and body, both in the short- and long-term.

There is some evidence that muscle activation during exercise allows more tryptophan, which the body converts to serotonin, to cross the blood-brain barrier.

Most of the evidence for exercise increasing serotonin comes from animal studies, though there are some examples in humans.

Increasing serotonin levels is one of several ways in which exercise might treat depression.

3. Diet

Foods that contain tryptophan could increase serotonin production in the body.

Tryptophan is an essential amino acid in many foods, including:

• salmon
• chicken
• turkey
• eggs
• spinach
• seeds
• milk products
• soy products
• nuts

There are also supplements that contain tryptophan.

Consuming these foods can increase the amount of tryptophan in the body. Research in animals suggests that increasing tryptophan may influence serotonin levels in the brain.

4. Light

Exposure to bright light may also affect serotonin levels.

Seasonal affective disorder (SAD) is a type of depression in which the symptoms correlate with the seasons. People with this condition may experience depressive symptoms during the winter when there is less sunlight.

The causes of SAD are unclear, but one theory is that poor sun exposure during the winter causes lower serotonin levels. These lead to symptoms of depression.

Light therapy is a treatment for the disorder that may increase serotonin levels. A 2015 study found that light therapy can increase serotonin levels in people with SAD.