Key takeaways

  • Neurotransmitters are chemical messengers that transmit signals from nerve cells to target cells by attaching to specific receptors. After delivering their messages, the body breaks them down or recycles them.
  • The brain needs neurotransmitters to regulate essential functions like heart rate, breathing, sleep cycles, digestion, mood, concentration, appetite, and muscle movement.
  • Examples of neurotransmitters include acetylcholine (which triggers muscle contractions), dopamine (important for memory and movement), serotonin (which helps regulate mood and sleep), and gamma-aminobutyric acid (GABA), the nervous system’s main inhibitor.

Neurotransmitters are part of the nervous system. They play a crucial role in human development and many bodily functions.

This article explains what neurotransmitters are, what they do, and some different types.

The nervous system controls the body’s organs and plays a role in nearly all bodily functions. Nerve cells, also known as neurons, and their neurotransmitters play important roles in this system.

Neurotransmitters are the body’s chemical messengers. They are molecules used by the nervous system to transmit messages between neurons, or from neurons to muscles.

Neurotransmitters relay their messages by traveling between cells and attaching to specific receptors on target cells.

Each neurotransmitter attaches to a different receptor. For example, dopamine molecules attach to dopamine receptors. When they attach, it triggers an action in the target cells.

After neurotransmitters deliver their messages, the body breaks them down or recycles them.

The brain needs neurotransmitters to regulate many necessary functions, including:

Neurotransmitters also play a role in early human development.

Experts have identified over 100 neurotransmitters to date and continue to discover more.

Neurotransmitters have different types of actions:

  • Excitatory neurotransmitters encourage a target cell to take action.
  • Inhibitory neurotransmitters reduce the likelihood that the target cell will take action. In some cases, these neurotransmitters have a relaxation-like effect.
  • Modulatory neurotransmitters can send messages to many neurons at the same time. They also communicate with other neurotransmitters.

Some neurotransmitters can perform multiple functions depending on the receptor they bind to.

The following sections describe some of the best-known neurotransmitters.

Acetylcholine is an excitatory neurotransmitter with a wide range of roles.

For example, it:

  • triggers muscle contractions
  • stimulates saliva and sweat production
  • controls the heartbeat

It also plays a role in memory, motivation, and attention.

Low levels of acetylcholine are linked with issues relating to memory and thinking, such as Alzheimer’s disease.

Some Alzheimer’s disease medications help slow the breakdown of acetylcholine in the body. This can help manage some symptoms, such as memory loss.

High levels of acetylcholine can lead to excessive muscle contraction. This may initially present as muscle twitching, followed by severe muscle weakness and paralysis, including weakness of the muscles used for breathing.

This can lead to:

  • increased saliva and tears
  • muscle weakness and paralysis
  • diarrhea
  • blurry vision

The nutrient choline, present in many foods, is a building block of acetylcholine. People need choline in their diet to produce enough acetylcholine. A 2024 study of older adults in China, spanning 20 years, found that higher dietary choline intake was associated with higher cognitive scores in both males and females.

Choline is present in beef liver, eggs, soybeans, and potatoes. Choline supplements are also available. However, there is not enough evidence to show they help with any health condition. However, taking too much can have adverse effects, such as a fishy body odor, sweating, low blood pressure, and liver damage.

Dopamine is important for:

Many people know dopamine as a neurotransmitter associated with pleasure and reward. The brain releases dopamine during pleasurable activities.

Dopamine levels also spike before a person is rewarded, providing the energy and focus necessary to achieve the reward.

Researchers believe there is a link between dopamine deficiency and Parkinson’s disease.

Drugs that regulate dopamine levels may help treat features of Parkinson’s disease as well as depression, addiction, anxiety, bipolar disorder, and other conditions.

The body needs certain amino acids to produce dopamine. Amino acids are present in protein-rich foods, such as meat, fish, and eggs. However, there is no evidence that eating these foods affects dopamine levels.

While there are no dopamine supplements, exercise may help boost levels naturally. Research has shown that regular, intense exercise improves dopamine signaling in people with early stage Parkinson’s disease.

Medical Perspective

“Although there are no established, ideal values for neurotransmitter levels, one can optimize neurotransmitter function through several lifestyle choices. The three main ways to achieve this is through regular exercise, getting a sufficient quantity of high quality sleep, and minimizing stress.”

— Susan W Lee, DO

Read more: Natural methods to increase dopamine levels

Quotes represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

Endorphins are both neurotransmitters and neurohormones involved in pain, stress, mood, and reward. They inhibit pain signals and create a feeling of pleasure and have links to laughter, love, sex, and appetizing food.

Many people feel better after exercising. One reason for this may be that exercise boosts endorphin levels.

Endorphins may also help manage pain. A 2020 review of research says that aerobic exercise can help prevent migraine frequency, duration, and intensity.

The Arthritis Foundation recommends exercise for people with fibromyalgia to reduce pain and boost mood.

Epinephrine (also known as adrenaline) plays a role in the body’s “fight-or-flight” response. It is both a hormone and a neurotransmitter.

When a person experiences stress or fear, their body releases epinephrine. This increases heart rate and breathing and gives the muscles a jolt of energy. It also helps the brain make quick decisions.

However, chronic stress can cause the body to release too much epinephrine. Over time, stress can lead to health problems such as decreased immunity, high blood pressure, diabetes, and heart disease, according to the National Institute of Mental Health.

Doctors can use epinephrine to treat some life threatening conditions, including:

Epinephrine’s ability to constrict blood vessels can reduce swelling caused by allergic reactions and asthma attacks. In addition, it can help the heart contract again if it has stopped during cardiac arrest.

Gamma-aminobutyric acid (GABA) is the central nervous system’s main inhibitor. It is a mood regulator, and experts have linked low levels of it with anxiety, depression, and schizophrenia.

Benzodiazepines, or “benzos,” are drugs that can treat anxiety. They work by increasing GABA’s action. This has a calming effect that can help treat anxiety attacks.

GABA comes in supplement form. A 2025 animal study found that GABA supplementation reduced anxiety behaviors in mice. However, clinical studies are necessary to understand the effect in humans.

Serotonin is a neurotransmitter that helps regulate mood, behavior, sleep, and memory.

Seasonal affective disorder (SAD) causes symptoms of depression in the fall and winter when daylight is less abundant. There may be a link between SAD and low serotonin levels.

Doctors prescribe selective serotonin reuptake inhibitors (SSRIs) to treat a range of conditions, including:

SSRIs boost serotonin levels by stopping the body from reabsorbing serotonin, leaving more serotonin to pass messages between nerve cells.

Serotonin-norepinephrine reuptake inhibitors (SNRIs) increase serotonin and norepinephrine, another neurotransmitter. SNRIs can help relieve symptoms of depression, anxiety, chronic pain, and fibromyalgia.

A precursor to serotonin, 5-hydroxytryptophan, is available as a supplement. Some studies suggest this ingredient may help treat depression and other conditions. However, more research is necessary.

People should speak with a doctor before taking this supplement, or any supplement, to treat depression.

While neurotransmitters are often associated solely with the brain, many of them are produced in the gastrointestinal tract. Around 95% of the body’s serotonin is found in the gut.

Through the gut-brain axis, the microbes in the digestive system communicate with the central nervous system. This explains why digestive health is so closely linked to mood and mental clarity.

Disruption in the gut-brain axis is thought to play a role in several conditions, including depression, Alzheimer’s disease, and Parkinson’s disease.

Research into the “second brain” (the enteric nervous system) is currently one of the most active areas of neuroscience, offering new insights into treating both GI disorders and anxiety.

Neurotransmitters contribute to nearly every function in the human body. An appropriate balance of neurotransmitters can help treat symptoms of certain health conditions, such as depression, anxiety, and Parkinson’s disease.

There is no proven way to ensure that neurotransmitters are balanced and working correctly. However, consuming a nutritious diet, getting regular exercise, and stress management can help in some cases.

Some people try supplements to boost certain neurotransmitters. In most cases, there is not enough evidence to show they work. Anyone considering using supplements should first check with a doctor. Supplements can interact with medications and may not be safe to use with some health conditions.

Anyone experiencing symptoms that may be due to an imbalance should seek medical advice.

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