The liquid volume does not tell you the dose
Check the amount of melatonin per measured volume on the exact preparation. Milligrams describe the ingredient amount, while milliliters describe the liquid volume. Use the supplied measuring device and pharmacist instructions; a kitchen spoon or a dropper from another bottle is not an interchangeable measure. [1][2]
Changing form changes the comparison
NHS distinguishes standard preparations from slow-release tablets and provides different administration instructions. A person should not crush a slow-release tablet to make a homemade liquid or assume that an equal-looking volume reproduces its release pattern. A swallowing difficulty is a reason to ask about an appropriate formulation. [1]
A concentration example
Imagine one oral liquid contains 1 mg per mL and another contains 2 mg per mL. The same 1 mL volume supplies twice as much in the second product. This is an arithmetic illustration, not a recommended dose or a claim about a particular marketed bottle. Check each new label even when the ingredient name stays the same. [1]
| Situation | Response or distinction |
|---|---|
| 1 mL at 1 mg/mL | 1 mg ingredient |
| 1 mL at 2 mg/mL | 2 mg ingredient |
| Equal volume | Not necessarily equal dose |
Sources for this article
- How and when to take melatonin - NHS
Source consulted: 2026-09-20. This is a reference resource, not a claim that we conducted the studies or tested a product. - About melatonin - NHS
Source consulted: 2026-09-20. This is a reference resource, not a claim that we conducted the studies or tested a product.