Anirva sells Sleep Harmony, a dietary supplement that contains melatonin. This article shares research for general education and is not medical advice.
If you have felt more anxious since starting melatonin, it is natural to wonder whether the supplement is the cause. It may be in some people, but medical sources list mild anxiety as a less common effect, and how often it happens is not well measured. Headache, dizziness and drowsiness are reported more often. Poor sleep, dreams, dose and other ingredients can also play a part.
In this article
Key Takeaways
- Possible, but less common. Mayo Clinic and Cleveland Clinic list mild anxiety, irritability and short-term low mood as less common effects.
- Usually mild and short. A review of 50 controlled studies found that melatonin's side effects were generally minor and short-lived.
- The rate is not well measured, because anxiety is rarely tracked on its own.
- Other explanations are common. Poor sleep, vivid dreams, dose and other ingredients can all play a part.
- Melatonin is one part of Sleep Harmony. The studies looked at melatonin by itself, so they do not describe the whole formula.
What Do Medical Sources Say About Melatonin and Anxiety?
Mayo Clinic lists headache, dizziness, nausea and daytime drowsiness as the most common melatonin effects. It puts short-term low mood, irritability and mood swings among the less common ones, and Cleveland Clinic's list of less common effects includes mild anxiety.
A 2019 review of 50 controlled studies of oral melatonin found that 26 reported no statistically significant side effects. The other 24 reported at least one, and these were generally minor, short-lived and easy to manage. The most common ones related to fatigue, mood, or thinking and movement performance. The abstract groups mood effects together, so it gives no separate rate for anxiety.
Why Is the Answer Not Clearer?
Anxiety is hard to pin on one cause, and many trials were built to test sleep or other outcomes rather than mood. Side effects are often listed in short lists or broad groups such as "mood." That makes it hard to say how often anxiety happens, or whether it happens more than with a placebo.
What Else Can Feel Like Anxiety After Melatonin?
Poor sleep. A brain-imaging study of 18 healthy adults found that a night without sleep raised brain activity linked to worry about what comes next. The effect was largest in people who were naturally more anxious. So if melatonin is not helping you sleep, worse sleep may feel like anxiety.
Vivid dreams. Melatonin can increase REM sleep, the stage linked to vivid dreams, according to Cleveland Clinic. It also says there is no clear proof of how melatonin affects dreams, and that people tend to have more vivid dreams when they are anxious or stressed.
Dose and product. High doses are more likely to cause side effects, and label amounts can be off. A 2017 study found melatonin content from 83% below to 478% above the label.
Timing. The 2019 review suggested that most side effects can likely be avoided or managed by dosing in line with the body's natural rhythm.
Medicines and other ingredients. Some medicines, such as fluvoxamine, can raise melatonin levels. Blends also contain other active ingredients, and any of them could be involved.
What About Mood and Depression?
Older reports raised some worry about mood. A 1976 study using 250 to 1,200 mg a day reported worse depression. A later study of people with depression taking 0.5 to 6 mg a day for up to 3.5 years did not report worsening. Mayo Clinic lists short-term low mood as a less common effect.
Melatonin Has Also Been Studied for Anxiety Before Surgery
Melatonin has also been tested for the opposite effect. A Cochrane review of 27 trials covering 2,319 adults found that melatonin probably lowers anxiety before surgery compared with placebo. The average drop was about 12 points on a 100-point scale, with moderate certainty. Those were doses given before surgery, so the result does not show that melatonin treats everyday anxiety.
Melatonin Is One Part of Sleep Harmony
If you are taking Sleep Harmony, melatonin is one of several ingredients rather than the only one. Sleep Harmony combines melatonin, calming herbs and three probiotics in one formula, and we chose ingredients that have each been studied for relaxation and sleep.
The studies above looked at melatonin by itself, so they do not describe the whole formula, and the finished formula has not been clinically tested. If you notice anxiety after starting any blend, it is worth mentioning to a clinician, since any ingredient could be involved.
A Quick Look at the Research
| Question | Research | What It Found | How Solid | Worth Knowing |
|---|---|---|---|---|
| Mild anxiety as a side effect | Clinic side-effect lists | Listed as less common | Limited | No rate given |
| Mood side effects overall | Review of 50 controlled studies | Generally minor and short-lived | Moderate | Mood not split into anxiety |
| Low mood at very high doses | 1976 report; later study at 0.5–6 mg | Worse at 250–1,200 mg; no worsening at usual doses | Limited | Old report; small groups |
| Anxiety before surgery | Cochrane review, 27 trials | Probably lowers anxiety | Moderate | Surgery setting |
| Vivid dreams | Expert comment | No clear proof | Insufficient | Not well studied |
Good to Know
If You Notice Anxiety After Starting Melatonin
If you notice anxiety after starting melatonin, it can help to jot down when it happens, along with your sleep, dose and any other new products or medicines. That makes the cause easier to sort out with a clinician.
It is fine to stop a supplement that makes you feel worse, and in long-term trials of 2 mg prolonged-release melatonin, stopping did not cause withdrawal symptoms. If the anxiety is strong, lasts, or gets in the way of daily life, a healthcare provider can help.
The Short Version
Can melatonin cause anxiety? It may in some people, but it is listed as a less common effect and the rate is not well measured. Poor sleep, vivid dreams, dose and other ingredients can also explain anxiety after starting a supplement, and a clinician can help if it is strong or lasting.
Frequently Asked Questions
Does melatonin cause anxiety?
Can melatonin cause anxiety the next day?
Can melatonin cause nightmares or vivid dreams?
Can melatonin help with anxiety?
What should I do if melatonin makes me anxious?
Does Sleep Harmony work the same way as melatonin alone?
References
- Mayo Clinic Staff. Melatonin side effects: What are the risks? Mayo Clinic. mayoclinic.org
- Mayo Clinic. Melatonin: uses, side effects and interactions. Mayo Clinic. mayoclinic.org
- Cleveland Clinic. Can melatonin cause bad dreams? What experts say. August 6, 2021. health.clevelandclinic.org
- Foley HM, Steel AE. Adverse events associated with oral administration of melatonin: a critical systematic review of clinical evidence. Complement Ther Med. 2019;42:65–81. pubmed.ncbi.nlm.nih.gov PMID 30670284; DOI 10.1016/j.ctim.2018.11.003.
- Givler D, Givler A, Luther PM, et al. Chronic administration of melatonin: physiological and clinical considerations. Neurol Int. 2023;15(1):518–533. mdpi.com DOI 10.3390/neurolint15010031.
- Madsen BK, et al. Melatonin for preoperative and postoperative anxiety in adults. Cochrane Database Syst Rev. 2020. pubmed.ncbi.nlm.nih.gov PMID 33319916; DOI 10.1002/14651858.CD009861.pub3.
- Goldstein AN, Greer SM, Saletin JM, Harvey AG, Nitschke JB, Walker MP. Tired and apprehensive: anxiety amplifies the impact of sleep loss on aversive brain anticipation. J Neurosci. 2013. news.berkeley.edu
- Erland LAE, Saxena PK. Melatonin natural health products and supplements: presence of serotonin and significant variability of melatonin content. J Clin Sleep Med. 2017;13(2):275–281. jcsm.aasm.org PMID 27855744; DOI 10.5664/jcsm.6462.
- AARP. Can melatonin help you sleep? And is it safe? November 2025. aarp.org
- Lemoine P, Garfinkel D, Laudon M, Nir T, Zisapel N. Prolonged-release melatonin for insomnia: an open-label long-term study of efficacy, safety, and withdrawal. Ther Clin Risk Manag. 2011;7:301–311. pubmed.ncbi.nlm.nih.gov PMID 21845053.
- National Center for Complementary and Integrative Health. Melatonin: what you need to know. NIH. nccih.nih.gov
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