Updated August 4, 2026
As of August 4, 2026 we found a trial called ROAR DIGAP that was published in abstract form Muscle & Nerve 2025;72:S95. Melatonin had no benefit. Thus, we change our Trials grade to F.
Updated April 29, 2026
As of April 29, 2026, we found 2 new studies that warrant grade changes. First, there is a newly completed clinical trial in which a small number of patients with ALS took melatonin and had no benefit on neurofilament light chain or ALSFRS-R slope (Muscle & Nerve 2025;72:S209). Thus, we change our TOE Trials Grade from U to F. Next, we found new data suggesting that melatonin has more side effects and risks than previously known including heart failure and death (https://newsroom.heart.org/news/long-term-use-of-melatonin-supplements-to-support-sleep-may-have-negative-health-effects). Thus, we change our TOE Risks Grade from B to D
Key Information
Click on any letter grade below for more info:
Preclinical Trials Grade:
C
Published: Jun 2021
Melatonin has plausible mechanisms, some positive (and some negative) pre-clinical data, and two case reports in which it was part of a cocktail of treatments associated with recovery of lost motor function. As we have stated previously, there are
multiple possible explanations for cases like these. There was also a very small, flawed retrospective study suggesting that PALS taking it progressed more slowly and lived longer than PALS were not taking it. Melatonin appears safe at high doses, but evidence is lacking for a proven benefit in slowing disease progression in ALS. Furthermore, an optimal dose and route of administration have not been established. Based on this data, a pilot trial of melatonin in PALS would be reasonable, but we cannot yet recommend it as an ALS treatment.
Grade A: Shown in a peer-reviewed publication to act on a relevant mechanism in humans
Grade B: Shown in a peer-reviewed publication to act on a relevant mechanism in pre-clinical model(s)
Grade C: Theoretically and plausibly acts on an ALS-relevant mechanism in humans
Grade D: Acts on a biological mechanism but it is not clear that this mechanism is relevant in ALS
Grade F: Implausible; would violate known principles or laws of biology
Grade U: No useful information was found for this category
Grade A: Two or more peer-reviewed publications reporting benefits in well-designed studies.
Animal studies are assumed to be ‘well designed’ when they follow published guidelines. When they deviate from these they are considered ‘flawed’.
Grade B: One peer-reviewed publication reporting benefits in a well-designed study.
Animal studies are assumed to be ‘well designed’ when they follow published guidelines. When they deviate from these they are considered ‘flawed’.
Grade C: One or more peer-reviewed publication(s) reporting benefits in flawed studies.
Animal studies are assumed to be ‘well designed’ when they follow published guidelines. When they deviate from these they are considered ‘flawed’.
Grade D: One or more non-peer reviewed studies reporting benefits (published on a website or in an abstract)
Grade F: The only studies available show no benefit
Grade U: No useful information was found for this category
Grade A: One or more peer-reviewed publications reporting benefits with validated diagnosis and benefits
Grade B: More than one unpublished report of benefit with validated diagnosis and benefits
Grade C: One unpublished report of benefit with validated diagnosis and benefits
Grade D: Subjective report(s) of benefit without validated diagnoses and/or benefits
Grade F: The only reports available show no benefit
Grade U: No useful information was found for this category
Two or more peer-reviewed publications describing benefits in well-designed randomized, blinded placebo-controlled phase III trials
Grade C: One or more peer-reviewed publications reporting benefits in a well-designed randomized, blinded, placebo-controlled phase I or II trial
Grade D: One or more peer-reviewed publications reporting benefits in a flawed trial.
Flawed trials means those in which there are identifiable problems with patient selection, randomization, blinding, controls or follow-up. These have ‘high or unclear risk of bias’ according to published criteria. Well-designed trials are those that have ‘low risk of bias’.
Grade F: The only trials available show no benefit
Grade U: No useful information was found for this category
Grade A: No exposed patients appear to have experienced harms
Grade B: More than 0% but less than 10% of exposed patients experienced harms (no hospitalizations or deaths)
Grade B (oral): More than 0% but less than10% of exposed patients experienced harms (no hospitalizations or deaths)
Grade D (intravenous): More than 0% but less than 5% of exposed patients experienced death or hospitalizations
Grade C: At least 10% of exposed patients experienced harms (no hospitalizations or deaths)
Grade D: More than 0% but less than 5% of exposed patients experienced death or hospitalizations
Grade D: More than 0% but less than 5% of exposed patients experienced death or hospitalizations
Grade F: At least 5% of exposed patients experienced death or hospitalization
Grade F: At least 5% of exposed patients experienced death or hospitalization
Grade U: No useful information was found for this category
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