While melatonin is primarily known for regulating sleep cycles and is widely used as a natural sleep aid, some people report experiencing increased anxiety after taking it. This paradoxical effect raises important questions about melatonin's complex influence on the brain, which extends beyond sleep to affect mood, stress, and anxiety levels through intricate interactions with neurotransmitter systems and hormonal pathways.
The relationship between melatonin and anxiety is not fully understood. While numerous studies demonstrate melatonin's anxiolytic (anxiety-reducing) properties, clinical reports and patient experiences suggest that some individuals may experience heightened anxiety symptoms when using melatonin supplements. This examination explores why some people experience anxiety after taking melatonin and evidence-based strategies for safer sleep improvement.
Melatonin's effects on anxiety involve complex interactions with multiple neurotransmitter systems and neural pathways beyond simple sleep promotion. The hormone exerts its effects through both receptor-mediated mechanisms and direct neurochemical interactions that can influence mood and anxiety.
We asked Dr. Suzanne Gorovoy, Sleep Expert, Clinical Psychologist, and Behavioral Sleep Medicine Specialist about melatonin's relationship with anxiety in clinical practice. She says:
"Melatonin isn't an anxiolytic, and in some sensitive individuals, it may worsen anxiety or cause mood fluctuations."
In other words, while melatonin is often perceived as universally calming, it doesn't function as a traditional anti-anxiety medication and can actually have opposite effects in certain people.
Neurotransmitter Interactions: Melatonin influences several key neurotransmitter systems directly involved in anxiety regulation. Research demonstrates that melatonin can increase levels of gamma-aminobutyric acid (GABA) in certain brain regions. While higher GABA levels generally produce calming effects, individual responses can vary significantly based on genetic factors and existing neurotransmitter balance.
Brain Wave Pattern Changes: Neuroimaging studies reveal that melatonin affects brain wave patterns, particularly increasing alpha wave activity associated with relaxation while decreasing beta wave activity linked to alertness and anxiety. However, these electroencephalogram changes don't affect everyone the same way, and some individuals may experience paradoxical responses.
HPA Axis Modulation: Melatonin's interaction with the hypothalamic-pituitary-adrenal (HPA) axis represents another crucial mechanism. By influencing stress hormone levels like cortisol, melatonin can indirectly affect anxiety levels and emotional regulation. In sensitive individuals, this hormonal modulation may trigger rather than reduce anxiety.
The relationship between melatonin and serotonin is fundamental to understanding how melatonin supplementation might influence anxiety levels. Serotonin serves as the direct precursor to melatonin synthesis, and disturbances in this relationship may contribute to anxiety-related side effects.
During melatonin synthesis, serotonin is converted to melatonin through enzymatic processes involving N-acetylation and methylation. This conversion means that melatonin production is directly dependent on serotonin availability, creating a complex interplay between these neurochemicals.
Since serotonin plays a crucial role in mood regulation and low serotonin levels are strongly correlated with anxiety, the timing and dosage of melatonin supplementation may influence this delicate serotonin-melatonin balance. Individual variations in serotonin metabolism and receptor sensitivity may explain why some people experience anxiety-related side effects from melatonin.
Laboratory analysis has revealed that some commercial melatonin products contain serotonin as a contaminant, potentially leading to unpredictable effects on neurotransmitter balance. Studies have shown significant variability in melatonin content among commercial products, making it difficult to predict individual responses.
Yes, while the majority of research demonstrates melatonin's anxiety-reducing effects, clinical observations and patient reports indicate that some individuals do experience increased anxiety after taking melatonin supplements. A systematic review of melatonin research identified serious adverse events including agitation, fatigue, mood swings, and anxiety-like symptoms, though these remain relatively uncommon.
A landmark study from 1976 found that melatonin "exacerbated symptoms of dysphoria" in depressed patients and caused sleep loss and other concerning symptoms. While this early research focused on depressed patients, it highlighted the potential for melatonin to worsen mood-related symptoms in vulnerable individuals.
More recent research has been more positive overall, with multiple studies demonstrating melatonin's anxiolytic effects in both animal models and human subjects. However, individual variability in response remains significant.
Neurotransmitter Imbalance: In sensitive individuals, melatonin's complex effects on neurotransmitter balance, particularly its influence on serotonin and dopamine systems, might create imbalances that manifest as anxiety symptoms.
Hormonal Sensitivity: Some people may be more sensitive to exogenous hormone supplementation. Taking melatonin supplements may temporarily disrupt the balance of stress-related hormones such as cortisol, potentially triggering anxiety symptoms.
Timing and Dosage Issues: Taking melatonin at inappropriate times or in excessive doses can disrupt natural circadian rhythms, potentially leading to feelings of disorientation, restlessness, or anxiety.
Some anxiety symptoms attributed to melatonin may result from secondary effects:
Understanding risk factors can help individuals make informed decisions about melatonin use and identify when professional guidance might be beneficial.
Individuals with Pre-existing Anxiety Disorders: People with diagnosed anxiety disorders may be more vulnerable to experiencing increased anxiety with melatonin use. The already-heightened anxiety response in these individuals may make them more sensitive to any substance that affects neurotransmitter balance or hormonal regulation.
Hormonal Sensitivity: Individuals with adrenal dysfunction or cortisol dysregulation may be at increased risk for paradoxical reactions. Women experiencing hormonal fluctuations related to menstrual cycles, pregnancy, perimenopause, or menopause may also be more susceptible to mood-related side effects.
Medication Interactions: People taking multiple medications, particularly antidepressants (especially SSRIs), may experience unpredictable interactions. Blood pressure medications and immunosuppressive drugs also have documented interactions with melatonin that could contribute to anxiety symptoms.
Age-Related Factors: Children, adolescents, and elderly individuals may be at particular risk due to developing nervous systems, ongoing hormonal changes, or age-related changes in metabolism.
For individuals who wish to use melatonin but are concerned about potential anxiety-related side effects, several evidence-based strategies can help minimize risks.
We asked Dr. Daniel Jin Blum, Sleep Expert, Clinical Psychologist, and Research Assistant Professor of Psychology about optimal melatonin dosing strategies. He says:
"More isn't better with melatonin. In most cases, less than 1mg is sufficient to trigger a circadian shift."
This means that the commonly available high-dose melatonin supplements (3-10mg) may be unnecessarily potent and increase the risk of side effects including anxiety.
Start Low: Research consistently shows that lower doses of melatonin (0.3-1 mg) are often more effective than higher doses and carry a reduced risk of side effects. Clinical research indicates that doses as low as 0.5 mg can be effective for circadian rhythm regulation.
Time It Right: Melatonin should typically be taken 1-2 hours before desired bedtime to align with natural circadian rhythms. Taking it too early may cause premature sleepiness and disrupt evening activities.
Choose supplements that have been third-party tested for purity and potency. Studies have revealed substantial variability in melatonin content among commercial products, with some containing anywhere from 83% less to 478% more melatonin than labeled. Avoid products that combine melatonin with other ingredients to minimize the risk of unexpected interactions.
For individuals at higher risk, start with the lowest possible dose every other night or a few times per week. Keep a sleep and mood diary during initial weeks of use to identify patterns or correlations between supplement use and anxiety symptoms.
For those who experience anxiety with melatonin or prefer to avoid hormonal supplementation, several evidence-based alternatives exist:
Magnesium plays crucial roles in nervous system function and muscle relaxation. Clinical research demonstrates that magnesium supplementation can improve sleep quality and reduce anxiety without hormonal effects. Recommended dosage: 200-400 mg taken 30-60 minutes before bedtime.
This amino acid found in tea leaves increases alpha brain wave activity associated with relaxation while reducing anxiety without causing sedation. Unlike melatonin, L-theanine promotes a calm, relaxed state without directly affecting hormonal systems. Typical dosages: 100-200 mg taken 30-60 minutes before bedtime.
For sustainable, long-term sleep improvement without supplementation, CBT-I represents the gold standard approach. This evidence-based treatment addresses the thoughts, behaviors, and environmental factors that contribute to sleep difficulties and provides lasting benefits without side effects.
Research reveals a complex picture of melatonin's relationship with anxiety. A comprehensive systematic review found that melatonin significantly improved anxiety in postmenopausal women, while another major review demonstrated strong evidence that melatonin reduces preoperative anxiety better than placebo.
However, the same research noted that "only a few serious or clinically significant adverse events were reported, such as agitation, fatigue, mood swings, nightmares, skin irritation and palpitations". This highlights the importance of individual assessment and monitoring.
Professional medical guidance becomes important in several situations:
We asked Dr. Areti Vassilopoulos, Sleep Expert, Pediatric Health Psychologist, and Assistant Professor of Child Psychology about the importance of monitoring melatonin's effects on mental health. She says:
"Sleep supplements should always be used with awareness of how they affect both the mind and body—not just sleep timing."
This means that anyone using melatonin should pay attention to their overall mental state and mood, not just whether they're sleeping better.
While melatonin-induced anxiety is uncommon, it can occur through several potential mechanisms including neurotransmitter interactions, hormonal sensitivity, and individual variations in metabolism. Understanding these risk factors can help individuals and healthcare providers make informed decisions about melatonin use and implement strategies to minimize adverse effects.
The key to safe and effective sleep improvement lies in a comprehensive approach that considers individual risk factors, underlying health conditions, and personal treatment goals. For those who experience anxiety with melatonin, numerous evidence-based alternatives exist that can provide effective sleep support without hormonal effects.
Professional healthcare guidance becomes particularly important for individuals with pre-existing conditions, those taking multiple medications, or anyone experiencing persistent sleep difficulties. The ultimate goal remains achieving restorative, high-quality sleep without adverse effects on mood or anxiety levels.
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Melatonin-induced anxiety is relatively uncommon but well-documented. Clinical studies report that serious adverse events like agitation and mood swings occur in only a small percentage of users. However, individual susceptibility varies significantly based on factors like existing mental health conditions, medication interactions, and genetic variations in melatonin metabolism.
Anxiety symptoms from melatonin can occur within hours of taking the supplement, typically within 1-3 hours as the hormone reaches peak levels in the bloodstream. Some people may notice increased anxiety the morning after taking melatonin, while others might experience it during the initial drowsy period. The timing often depends on the formulation (immediate vs. extended-release) and individual metabolism rates.
If you experience anxiety after taking melatonin, discontinue use immediately and consult with a healthcare provider. Document when the anxiety occurs, its severity, and any other symptoms in a diary. Don't attempt to "push through" anxiety symptoms hoping they'll resolve, as this can worsen the experience. Consider natural alternatives like magnesium or L-theanine, and focus on sleep hygiene improvements while seeking professional guidance.
There's no reliable evidence that people can build tolerance to melatonin's anxiety-inducing effects. Unlike some medications where side effects diminish over time, anxiety reactions to melatonin often persist or worsen with continued use. The mechanisms behind melatonin-induced anxiety involve fundamental neurotransmitter and hormonal pathways that don't typically adapt to repeated exposure.
Yes, several factors may indicate higher risk for anxiety reactions: a personal or family history of anxiety disorders, sensitivity to other supplements or medications, existing hormonal imbalances, current use of antidepressants or other mood-affecting medications, and previous paradoxical reactions to sleep aids. People who are particularly sensitive to changes in their mental state or have panic disorder may be especially vulnerable.
Most anxiety effects from melatonin resolve within 24-48 hours after discontinuation, as the supplement has a relatively short half-life of about 30-60 minutes. However, some people may experience lingering effects for several days, particularly if they were taking high doses or extended-release formulations. Individual metabolism rates significantly influence clearance times.
Lower-dose formulations (0.3-1mg) are generally less likely to cause anxiety compared to high-dose products (3-10mg). Third-party tested, pharmaceutical-grade melatonin with consistent dosing may reduce unpredictable effects. Immediate-release formulations are often better tolerated than extended-release versions for anxiety-prone individuals. Avoid combination products that include other herbs or compounds, as these increase the risk of unexpected reactions.
Not necessarily, but extra caution is warranted. People with pre-existing anxiety disorders are at higher risk for paradoxical reactions, but some may still benefit from melatonin when used appropriately. The key is starting with very low doses (0.3mg or less), timing it correctly, and working closely with a healthcare provider who understands both the sleep disorder and anxiety condition.
Yes, melatonin can interact with various anxiety medications. It may enhance the sedative effects of benzodiazepines and can interact unpredictably with SSRIs and other antidepressants. These interactions can either amplify anxiety symptoms or cause excessive sedation. Always consult with your prescribing physician before combining melatonin with any anxiety or depression medications.
Normal side effects typically include mild drowsiness, slight dizziness, or headache that resolve quickly. Anxiety reactions involve more concerning symptoms like racing thoughts, restlessness, panic sensations, mood swings, or feeling "wired but tired." True anxiety reactions often worsen rather than improve with continued use and may be accompanied by physical symptoms like increased heart rate or agitation.
Yes, and children may be particularly vulnerable to mood-related side effects from melatonin. The safety and long-term effects of melatonin in children haven't been fully established, and their developing nervous systems may react unpredictably. Children showing signs of increased anxiety, behavioral changes, or mood swings while taking melatonin should discontinue use and consult with a pediatrician immediately.
If you've previously experienced anxiety from melatonin, it's generally not recommended to retry it without professional guidance. The underlying sensitivity that caused the initial reaction is unlikely to have changed. Instead, focus on proven alternatives like improved sleep hygiene, magnesium supplementation, or CBT-I techniques. If you do decide to retry melatonin, do so only under medical supervision with the lowest possible dose and careful monitoring.
Dr. Shiyan Yeo
Dr. Shiyan Yeo is a medical doctor with over a decade of experience treating patients with chronic conditions. She graduated from the University of Manchester with a Bachelor of Medicine and Surgery (MBChB UK) and spent several years working at the National Health Service (NHS) in the United Kingdom, several Singapore government hospitals, and private functional medicine hospitals. Dr. Yeo specializes in root cause analysis, addressing hormonal, gut health, and lifestyle factors to treat chronic conditions. Drawing from her own experiences, she is dedicated to empowering others to optimize their health. She loves traveling, exploring nature, and spending quality time with family and friends.