Melatonin Side Effects
Overview
Melatonin is a hormone that helps control the sleep-wake cycle, and many people use melatonin supplements as a sleep aid. While melatonin is generally considered safe for short-term use, it can cause side effects that everyone should know about before starting a new supplement. Some of the most common side effects of melatonin include drowsiness, headache, nausea, and dizziness.
What Is Melatonin and How Does It Work?
The pineal gland in the brain makes melatonin, which helps control the body’s sleep-wake cycle. Melatonin levels in the blood usually rise in the evening and fall in the morning. When it gets dark, the brain increases melatonin production, making people feel sleepy.
Light lowers melatonin levels, which helps people wake up. This process is part of the body’s circadian rhythm. People may take melatonin supplements to help with sleep problems, such as insomnia, jet lag, and shift work changes.
Main Roles of Melatonin in the Body:
- Regulates sleep-wake cycles.
- Signals the body it is time to sleep.
- Supports healthy circadian rhythms.
Melatonin supplements come in pill, liquid, or chewable forms. The body does not become addicted to melatonin, and most people use it for short periods. Some people take melatonin to reset their sleep cycle after travel or to manage delayed sleep phase. Research states that melatonin mainly helps people fall asleep, especially if their body clock is off.
Melatonin supplements do not work for everyone. The effects depend on timing, dosage, and individual differences. It’s important to talk to a doctor before starting melatonin, especially for children or those with health problems.
Common Side Effects of Melatonin
Many people use melatonin to help sleep, but some notice unwanted effects. These side effects can vary depending on the dose and the person.
Daytime Sleepiness and Drowsiness
Daytime sleepiness is a common side effect. People may feel groggy, unusually tired, or less alert after waking up. Even after a full night of rest, drowsiness can continue into the morning or afternoon. When people take too much melatonin or it stays in their system, it can interfere with normal wakefulness during the day. Some may find it hard to concentrate, react more slowly, or feel the urge to nap.
Tips to Reduce Daytime Sleepiness
- Take melatonin earlier in the evening.
- Use the lowest effective dose.
- Avoid driving or operating machinery if feeling drowsy.
Headaches and Dizziness
Headaches can happen after taking melatonin. Some people may experience mild to moderate head pain. The reason for this is not fully clear, but it may relate to how melatonin affects brain chemicals. Dizziness may also occur, affecting balance and stability. This effect might last for a short time after waking, especially in those sensitive to changes in sleep patterns or hormones.
The combination of headaches and dizziness can make daily tasks harder if symptoms are frequent or intense. If headaches or dizziness happen often, lowering the dose or talking with a healthcare provider may help. Drinking water, resting, and avoiding sudden movements may also lessen these effects.
Vivid Dreams and Nightmares
Some people notice more vivid dreams or nightmares while taking melatonin. Dreams can become more memorable, intense, or emotional. Melatonin can influence the REM stage of sleep, which is when most dreaming happens.
While vivid dreams are not always negative, nightmares may cause stress or disturb sleep. Children and people with a history of nightmares may be more affected. If frightening dreams become a problem, taking a lower dose or adjusting the timing of melatonin may help.
Keeping a sleep diary can help track changes in dreams and sleep quality. If nightmares continue or worsen, a healthcare provider can give guidance on whether to continue melatonin.
Serious and Less Common Side Effects
Melatonin is usually safe, but some people may experience side effects that are more severe or unexpected. These effects are less common, but can still be important for users to know about, especially if symptoms become persistent or worsen.
Confusion and Disorientation
Some people feel confused or disoriented after taking melatonin. This can show up as trouble thinking clearly, forgetfulness, or difficulty paying attention. In some cases, these symptoms can affect daily activities or make it hard to perform tasks that need focus, such as driving or using machinery.
Older adults face higher risk, especially if they already have memory concerns or take other medications that affect their mind. Ongoing confusion is a sign to stop taking melatonin and speak with a doctor.
Signs of Confusion
| Symptom | Description |
|---|---|
| Disorientation | Not knowing time or place. |
| Memory trouble | Forgetting simple tasks or details. |
| Trouble focusing | Hard to keep attention on one thing. |
Anyone who develops these warning signs should talk with a medical provider to make sure melatonin is not causing harm.
Mood Changes and Depression
Rarely, melatonin may affect mood. While most people do not notice emotional changes, a small number may experience short-term depression, sadness, or increased irritability after taking the supplement. These mood changes may show up as feeling down, losing interest in normal activities, or being easily upset.
People with a history of depression or mood disorders could be more sensitive to these side effects. If these feelings start soon after beginning melatonin and do not improve, it is important to contact a healthcare professional for advice.
Possible Mood-Related Side Effects
- Sadness or low mood
- Irritability
- Loss of interest in hobbies
If depression symptoms appear, stop using melatonin until a doctor can give advice.
Potential Allergic Reactions
Although rare, allergic reactions to melatonin can happen. These responses may range from mild skin rashes to more serious symptoms such as swelling, trouble breathing, or hives. Allergic reactions need fast medical attention. Signs to look out for include:
- Itching or rash
- Swelling of the face, lips, or tongue
- Wheezing or shortness of breath
If someone has these effects after taking melatonin, seek medical help at once. Do not use melatonin again unless a doctor says it is safe.
Melatonin Supplement Interactions and Precautions
Melatonin supplements can interact with different medicines and some health conditions. People should be careful if they take other drugs at the same time as melatonin.
Common Drug Interactions
| Medicine Type | Possible Effect |
|---|---|
| Blood thinners | Higher risk of bleeding. |
| Seizure medications | May change seizure control. |
| Diabetes drugs | Can affect blood sugar levels. |
| Birth control pills | May raise melatonin levels, causing extra drowsiness. |
| Immune suppressants | May increase immune activity. |
People who take birth control pills may already have higher melatonin levels. Taking extra melatonin can make them more sleepy or affect how their body reacts. Melatonin may change how the immune system works. People with autoimmune diseases or those taking immune suppressants should ask a doctor before using melatonin supplements. Possible side effects from mixing melatonin with other drugs include:
- Drowsiness
- Dizziness
- Headache
- Unusual changes in mood or alertness
Melatonin supplements are not advised for some people, like pregnant women without a doctor’s guidance, young children, or anyone with serious health problems. Use melatonin only as directed. Check with a healthcare provider before starting melatonin with other medicines.
Melatonin Side Effects in Special Populations
Some groups may react differently to melatonin. These include children, older adults, and people with certain health conditions.
- Children: Children sometimes use melatonin for sleep problems. Side effects in children are usually mild, such as drowsiness, headaches, and mood changes. Doctors usually suggest using the lowest effective dose because we don’t know much about long-term safety.
- Older Adults: Older adults may feel more drowsy, confused, or dizzy when they take melatonin. This can make falls more likely, especially for those with balance issues.
- People With Medical Conditions: Some health conditions can change how melatonin works. For example:
- People with epilepsy may have more seizures
- Melatonin can interact with blood thinners
- It may change blood sugar levels in people with diabetes
Melatonin and Specific Sleep Disorders
| Condition | Possible Side Effects |
|---|---|
| Insomnia | Drowsiness, headache, possible nausea |
| Delayed Sleep Phase Syndrome | Daytime sleepiness, mild stomach upset |
