Is melatonin a good sleep aid for ICU patients with critical illness?
Sleep is often poor in the intensive care unit (ICU), and poor sleep can slow recovery. Melatonin is a natural hormone that helps regulate sleep-wake cycles. Some small studies suggest melatonin can increase sleep time in critically ill patients, but the evidence is not strong. Current expert guidance recommends trying non-drug strategies — like reducing noise and light — before using any sleep medication, including melatonin.
What the research says
A small randomized trial from 2008 gave 10 mg of melatonin or a placebo to 24 ICU patients who had a tracheostomy. The melatonin group slept about 1 hour more at night, with a sleep efficiency index of 0.38 versus 0.26 in the placebo group 9. This suggests melatonin can improve sleep quantity, but the study was very small and only included a specific type of patient.
A 2024 point-prevalence study across 40 ICUs in Australia and New Zealand found that melatonin was the most commonly used sleep medication, given to 5.2% of patients. However, patients who received a sleep aid were awake for about the same amount of time overnight as those who did not, indicating that these medications may not always be effective 10.
A narrative review on ICU sleep notes that medications for sleep have had disappointing results in the ICU and may increase the risk of delirium and falls. The review recommends that non-pharmacologic measures — such as earplugs, eye masks, and reducing nighttime disruptions — should be tried first. If those fail, melatonin or melatonin receptor agonists may be considered, but only after other options have been exhausted 3.
What to ask your doctor
- What non-drug sleep strategies (like earplugs, eye masks, or reducing nighttime checks) are available in this ICU?
- If non-drug measures are not enough, is melatonin an option for me or my family member?
- What dose of melatonin has been studied in ICU patients, and what are the possible side effects?
- Could melatonin interact with other medications being given in the ICU?
- Are there any risks of using melatonin, such as worsening delirium or causing falls?
This question is drawn from common patient questions about Pulmonology & Critical Care and answered using cited medical research. We do not provide individualized advice.