The Study
The Absolute Bioavailability of Oral Melatonin
This study is like a tiny experiment that checks how much of a pill actually gets into your blood compared to an injection. It can only tell us the exact amount absorbed in these 12 people, not whether the pill actually helps with sleep or any health problem. We can't use it to prove that melatonin cures or prevents anything.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
This study checked how much melatonin actually gets into your blood when you take a pill versus an injection. It found that pills only deliver about 15% of the drug to your system, likely because your gut doesn't absorb it well or your liver breaks it down too quickly before it circulates.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 534 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This means standard melatonin pills are significantly less efficient at delivering the active compound to your bloodstream compared to direct injection, suggesting that higher pill doses might be necessary to achieve the same effect.
- 2Oral doses of 2 mg and 4 mg both had about 15% bioavailability.
- 3The time it takes for melatonin to leave your blood was the same whether taken as a pill or injection.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The Journal of Clinical Pharmacology
Year
2000
Authors
Roberto Demuro, A. Nafziger, D. Blask, A. Menhinick, J. Bertino
Related Content
Claims (4)
This means that no matter whether you take melatonin as a pill or get it through an IV, your body clears it out at the exact same speed once it's in your blood. The way you initially get the supplement into your system doesn't change how long it stays in your body.
When you take melatonin pills, your body only absorbs about 15% of it because your gut and liver break it down before it reaches your bloodstream. This is why you need to swallow a much larger pill by mouth to get the same effect as an injection or other non-oral methods.
When you take melatonin pills, your body only absorbs about 15% of the dose into your bloodstream because most of it gets broken down before it can circulate. This means oral supplements deliver much less active melatonin to your system compared to an injection.
Taking a higher dose of melatonin might help more of the supplement actually get into your bloodstream. This happens because larger amounts can overwhelm the liver's natural breakdown process, making the supplement more effective than standard low doses.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.