How You Take Melatonin Matters More Than You Think

When you take melatonin to help with sleep, you probably expect it to kick in and get to work. But what if how you take it really matters more than you thought? That’s exactly what the clinical trial NCT03951025 looked at: comparing the bioavailability of a melatonin-rich food supplement when taken sublingually (under the tongue) versus the usual oral route. 

Sleep-onset problems are widely recognized, and while oral melatonin is already used, it comes with some drawbacks: notably low bioavailability (meaning only a small proportion of the dose actually gets into the bloodstream) and a short half-life. By delivering it sublingually, the idea is to bypass part of the digestive system and first-pass liver metabolism (which can degrade the compound) and thereby improve how much of the active compound reaches circulation. 

In this study, adults over 18 years were recruited. They received a 1 mg dose of melatonin via the two routes (sublingual vs oral) and the researchers measured how much got absorbed and at what speed. The findings suggest that the sublingual route could indeed offer greater bioavailability—meaning more melatonin becomes active in the body—than the standard oral route.

What does this mean in practical terms? If sublingual melatonin is absorbed better, then a lower dose might produce the same effect (perhaps reducing side effects), it might act faster (helping you fall asleep sooner), and it may maintain more consistent effect across different people (since oral absorption can vary due to digestive differences). For people struggling with sleep onset, or who dislike large pills or slow acting tablets, sublingual delivery could be a more convenient and effective option.

Of course, this trial looked at healthy adult volunteers (not necessarily individuals with chronic insomnia), and it focused on bioavailability (absorption and levels in blood) rather than long-term sleep outcomes. So while the results are promising, they don’t yet mean that sublingual melatonin will automatically outperform oral melatonin in all cases. More research into sleep outcomes, dosage optimization, safety, and real-life efficacy will be needed.

For anyone considering melatonin supplements, this trial highlights an important takeaway: delivery route matters. If you’re taking melatonin and finding it slow to act, or inconsistent, exploring a sublingual formulation (under guidance from a health professional) might be worthwhile. 

Sources:

• “Study of the Bioavailability of a Food Supplement Rich in Melatonin Administered Sublingually and Orally (MELATONIN)”. ClinicalTrials.gov Identifier: NCT03951025. ClinicalTrials.gov

• Summary of trial details and rationale: “Study of the Bioavailability of a Food Supplement Rich in Melatonin…” Network of Care (San Mateo County). Network of Care