Taking melatonin by injection results in about 110 times more of the drug in your blood compared to taking the same dose by mouth. This happens because your liver breaks down most of the oral melatonin before it reaches the rest of your body, which is why you need a much larger pill to get the same effect as a small injection.

When you swallow melatonin pills, your liver breaks down most of it before it can actually enter your bloodstream, meaning only about 2.5% of the dose actually works. Because so much is lost this way, you might need to take much higher oral doses to get the same effect as an injection.

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.

People process melatonin very differently, even when taking the exact same 10-milligram dose. Factors like your genes, metabolism, and body chemistry cause these wide differences, which is why it's so hard to create one-size-fits-all dosage recommendations.

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.

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.