Written by: THE BALANCE
Medically reviewed by Dr. Sarah Boss, MD
Last updated: January 19, 2026
Fact checked
Quick Summary
  • Serotonin, the neurotransmitter dubbed the "feel-good chemical," courses through your brain, and is responsible for regulating mood, appetite, and sleep.
  • It's the key player in keeping your mental and emotional well-being in balance.  But what if I told you that certain drugs can turn this harmony into chaos?  Yes, you heard it right!
  • Serotonin is a chemical that helps regulate various functions, including mood, sleep, and appetite.  When there is an excess of serotonin, it can lead to a wide range of symptoms and complications.
Reading time: 11 min

Serotonin, the neurotransmitter dubbed the “feel-good chemical,” courses through your brain, and is responsible for regulating mood, appetite, and sleep. It’s the key player in keeping your mental and emotional well-being in balance. 

But what if I told you that certain drugs can turn this harmony into chaos? 

Yes, you heard it right! In a twist of fate, some medications have the potential to send your serotonin levels skyrocketing, leading to a dangerous condition known as serotonin syndrome. 

Strap in for an eye-opening journey as we delve into the intriguing world of drugs that, unbeknownst to many, can tip the scales of serotonin and set off a cascade of alarming symptoms. 

Serotonin syndrome is a potentially life-threatening condition that occurs when there is an excessive amount of serotonin in your body. Serotonin is a chemical that helps regulate various functions, including mood, sleep, and appetite. 

When there is an excess of serotonin, it can lead to a wide range of symptoms and complications.

How Common Is Serotonin Syndrome

Serotonin syndrome is considered a relatively rare condition. The exact prevalence is difficult to determine, but it is estimated to occur in less than 1% of patients taking serotonergic medications.

However, the incidence may be higher in certain situations, such as when multiple serotonergic medications are used in combination or when medications are taken in excessive doses.

Symptoms of Serotonin Syndrome

The symptoms of serotonin syndrome can vary in severity, ranging from mild to severe. Here are some common signs to watch out for:

  • Agitation or restlessness
  • Confusion or disorientation
  • Rapid heart rate and high blood pressure
  • Dilated pupils
  • Excessive sweating
  • Tremors or muscle rigidity
  • Nausea, vomiting, or diarrhea
  • Headache
  • Shivering or goosebumps
  • In severe cases, seizures or loss of consciousness [1]

Who’s At Risk for Serotonin Syndrome?

While anyone can potentially develop serotonin syndrome, certain individuals may be more susceptible to this condition. Factors that increase the risk include:

Polypharmacy: Taking multiple medications that increase serotonin levels simultaneously.

Recent medication changes: Starting a new medication or adjusting the dosage can increase the risk.

Overdose: Taking excessive serotonergic medications can overwhelm the body’s ability to regulate serotonin.

Genetic factors: Some people may have genetic variations that make them more prone to serotonin syndrome.

Drug interactions: Combining certain medications or substances that affect serotonin can trigger the syndrome.

Serotonin syndrome is a potentially serious condition that requires prompt medical attention. If you experience any of the following symptoms or suspect serotonin syndrome, it is crucial to see your doctor or seek immediate medical care:

Severe Symptoms

If you experience severe symptoms such as high fever, seizures, or loss of consciousness, it is essential to seek emergency medical assistance right away.

Rapid Onset of Symptoms

If you develop symptoms suddenly or they rapidly worsen, it is advisable to see a healthcare professional promptly.

Combination of Symptoms

If you experience a combination of symptoms associated with serotonin syndrome, including agitation, confusion, rapid heartbeat, high blood pressure, dilated pupils, muscle rigidity, tremors, or gastrointestinal disturbances, it is essential to consult with a doctor.

Recent Medication Changes

If you have recently started a new medication, changed the dosage of an existing medication, or combined multiple medications that affect serotonin levels, it is crucial to inform your doctor and seek medical evaluation if symptoms arise.

History of Serotonin Syndrome

If you have a history of serotonin syndrome or have experienced adverse reactions to medications affecting serotonin levels in the past, it is important to be vigilant and seek medical attention if new symptoms arise.

From commonly prescribed medications to illicit substances, it’s time to uncover the hidden culprits that can send serotonin levels spiraling out of control. Let’s discover the common causes of serotonin syndrome.

Prescription Drugs That Can Cause Serotonin Syndrome

Serotonin syndrome can be triggered by several factors, including using certain prescription serotonergic drugs or combining multiple medications that increase serotonin levels. Some common causes include:

Selective serotonin reuptake inhibitors (SSRIs): These are a type of antidepressant that increases serotonin levels in the brain.

Serotonin and norepinephrine reuptake inhibitors (SNRIs): Similar to SSRIs, these medications also affect serotonin levels.

Monoamine oxidase inhibitors (MAOIs): These drugs prevent the breakdown of serotonin and other neurotransmitters, leading to an increase in serotonin levels.

Tricyclic antidepressants: Although not commonly prescribed anymore, these medications can also contribute to serotonin syndrome.

Opioids: Certain opioids, such as tramadol, can increase serotonin levels and raise the risk of serotonin syndrome.

What Illegal Drugs Affect Serotonin

Illegal drugs have the potential to disrupt the delicate balance of serotonin in our bodies, leading to the development of serotonin syndrome. 

Here’s a breakdown of some common illegal drugs that can affect serotonin levels:

MDMA (Ecstasy/Molly)

MDMA is known to significantly increase serotonin release and inhibit its reuptake [1]. Excessive serotonin accumulation can contribute to the development of serotonin syndrome.

DMT (Ayahuasca)

DMT acts on serotonin receptors, and its use can potentially disrupt serotonin balance [1]. Although serotonin syndrome is uncommon with DMT alone, caution should be exercised when combining it with other serotonergic drugs.

Psilocybin (Magic Mushrooms)

Psilocybin affects serotonin receptors, leading to alterations in serotonin levels [2]. While serotonin syndrome is rare with psilocybin use alone, it can occur if combined with other serotonergic drugs.

Amphetamines (Meth, Speed)

Amphetamines increase serotonin release and inhibit reuptake, potentially leading to excessive serotonin levels [3]. When used in high doses or combined with other serotonergic substances, amphetamines can increase the risk of serotonin syndrome.

Remember, illegal drugs not only pose the risk of serotonin syndrome but also carry numerous other health and legal risks. It’s crucial to prioritize your well-being and avoid engaging in illegal drug use.

When it comes to certain medications and illicit substances, it’s important to understand their potential impact on serotonin levels and the risk of serotonin syndrome. Let’s take a closer look at buspirone, trazodone, and LSD:

Can Buspirone Cause Serotonin Syndrome?

Buspirone is a medication commonly prescribed to treat anxiety disorders. 

It works differently from selective serotonin reuptake inhibitors (SSRIs) and does not significantly affect serotonin levels. 

While buspirone alone is not known to cause serotonin syndrome [1], it’s essential to consult with your healthcare provider regarding potential drug interactions or if you are taking other medications that affect serotonin.

Can Trazodone Cause Serotonin Syndrome?

Trazodone is an antidepressant medication primarily used to treat depression and sleep disorders. 

It can increase serotonin levels in the brain, but the risk of serotonin syndrome with trazodone alone is generally low. 

However, combining trazodone with other serotonergic drugs can increase the risk of serotonin syndrome. It’s crucial to inform your healthcare provider about all the medications you’re taking to ensure safe and appropriate use.

Does LSD Cause Serotonin Syndrome?

LSD (lysergic acid diethylamide) is a hallucinogenic drug that affects serotonin receptors in the brain.

While LSD can cause alterations in serotonin activity [3], serotonin syndrome specifically caused by LSD use alone is considered rare [4]. 

However, combining LSD with other serotonergic substances, such as certain antidepressants or MDMA, can significantly increase the risk of serotonin syndrome. It’s important to note that LSD use carries various other risks, including psychological effects and unpredictable reactions.

Cocaine is a powerful stimulant drug that can profoundly affect the brain’s chemistry, including the levels of serotonin. Let’s delve into the potential risks of developing serotonin syndrome when using cocaine:

Cocaine’s Impact on Serotonin Levels

Cocaine primarily acts by blocking the reuptake of dopamine, a neurotransmitter associated with pleasure and reward [5].

However, cocaine can also indirectly affect serotonin levels in the brain due to its interactions with other neurotransmitter systems.

Serotonin Syndrome and Cocaine Use

Serotonin syndrome can occur when there is an excessive accumulation of serotonin in the body, resulting in a range of symptoms.

While serotonin syndrome is typically associated with drugs that directly affect serotonin levels, such as antidepressants or hallucinogens, cocaine’s influence on multiple neurotransmitters can potentially contribute to its development [6].

Interactions and Risks

Cocaine use can lead to an increase in serotonin release, disrupting the delicate balance of this neurotransmitter in the brain [6].

Additionally, combining cocaine with other substances that affect serotonin levels, such as certain antidepressants or MDMA, significantly heightens the risk of serotonin syndrome.

The combination of cocaine and serotonergic drugs can overwhelm the body’s capacity to regulate serotonin, leading to potentially life-threatening complications.

Seeking Help and Staying Safe

It’s important to be aware of the potential risks associated with cocaine use, including the risk of serotonin syndrome.

If you or someone you know experiences symptoms such as agitation, confusion, muscle rigidity, or rapid heartbeat after using cocaine, seek immediate medical attention. Prompt diagnosis and treatment of serotonin syndrome can be crucial in preventing severe complications.

Phentermine is a prescription medication commonly used to aid in weight loss. While it primarily works as an appetite suppressant, it’s important to understand its potential impact on serotonin levels and the risk of serotonin syndrome:

How Phentermine Works

Phentermine is classified as a sympathomimetic amine and works by stimulating the release of norepinephrine, a neurotransmitter that suppresses appetite.

Unlike some other weight loss medications, phentermine does not directly affect serotonin levels in the brain.

Risk of Serotonin Syndrome

Serotonin syndrome occurs when there is an excessive accumulation of serotonin in the body, leading to a range of symptoms.

Phentermine alone is not known to cause serotonin syndrome [1].

However, it’s important to be cautious when taking phentermine in combination with other medications or substances that affect serotonin levels.

Interactions and Precautions

Combining phentermine with serotonergic drugs, such as certain antidepressants or MDMA, can increase the risk of serotonin syndrome.

It’s crucial to inform your healthcare provider about all the medications you’re taking, including over-the-counter drugs and herbal supplements, to ensure the safe use of phentermine.

Monitoring and Safety Measures

Healthcare professionals prescribing phentermine typically monitor patients closely for signs of serotonin syndrome.

If you experience symptoms such as agitation, confusion, rapid heart rate, or muscle rigidity while taking phentermine or after combining it with other medications, seek immediate medical attention.

Serotonin syndrome can be a serious condition, but there are several measures you can take to reduce the risk of its occurrence. Here are some important steps to prevent serotonin syndrome:

Open Communication

Ensure open and honest communication with your healthcare provider. Inform them about all the medications you are taking, including prescription drugs, over-the-counter medications, and herbal supplements.

Be sure to mention any history of serotonin syndrome or adverse reactions to medications.

Medication Management

Follow your healthcare provider’s instructions carefully regarding medication dosages and timing.

Avoid self-medication or taking multiple serotonergic medications without professional guidance.

Drug Interaction Awareness

Be aware of potential drug interactions. Research and ask your healthcare provider about any possible interactions between your medications.

Avoid combining medications or substances that affect serotonin levels without proper medical supervision.

Dose Adjustments

If you require multiple medications that affect serotonin levels, your healthcare provider may adjust the dosages to minimize the risk of serotonin syndrome.

Regularly review your medication regimen with your healthcare provider to ensure appropriateness and safety.

Educate Yourself

Learn about the signs and symptoms of serotonin syndrome. Be vigilant and seek medical attention immediately if you experience any potential symptoms.

Stay informed about the medications you are taking and their potential effects on serotonin levels.

It is vital to understand the potential risks associated with drugs that can cause serotonin syndrome. 

Remember, certain medications, whether prescribed or illicit, can disrupt the delicate balance of serotonin in our bodies. 

Stay informed about the medications you take, communicate openly with your healthcare provider, and be cautious when combining drugs that affect serotonin levels.

Prompt recognition of symptoms and seeking immediate medical attention are paramount in ensuring your safety. 

Prioritize your well-being by being vigilant, knowledgeable, and proactive in managing your medication regimen. 

Your health is of utmost importance, and with the right information and responsible choices, you can navigate the potential pitfalls and safeguard your overall well-being.

The Article

+

About This Article

+

Do you need help?

Sister Topics

Drug Abuse in Athletes Drug Addiction Statistics Drugs Abuse Drugs Addiction In India Drugs That Induce Psychosis Heroin Addiction Heroin Addiction Treatment How To Recover From Being Roofied How To Recover From Edibles Inpatient Drug Rehab Ketamine Addiction Treatment Khat, a herb or a drug Kratom Addiction Luxury Drug Addiction Rehab MDMA Addiction Monkey dust Addiction  Nicotine Withdrawal Poppers Drug Solpadeine Addiction Spice Addiction UK Steroid Abuse Steroid Addiction Symptoms Of A Comedown Vaping And Mental Health Vaping Dangers UK What are the Effects of Drugs on Heart What is 2C-B What is Drug Induced Psychosis Worst Drugs for Your Heart