Making and checking the ingredient
A melatonin tablet begins with an active ingredient that must be identified and tested. In the European Medicines Agency's assessment of Circadin, a prescription prolonged-release product, manufacturers produced melatonin chemically, purified it and controlled the resulting powder. The assessment describes analytical checks of identity, impurities and other quality characteristics. [1]
That is a documented manufacturing example, not a universal account of every over-the-counter melatonin product. An ingredient being the same molecule as a human hormone does not mean it was extracted from people or animals. Nor does the chemical name alone show that a retail batch contains the amount on its label. [1]
Turning powder into a tablet
The Circadin process uses milling, blending and granulation before compression into tablets. Blending distributes the active ingredient among the other ingredients; granulation changes the material into particles suited to processing; compression gives the tablet its shape. The formulation is designed to control release as well as produce a tablet that survives handling. [1]
Other ingredients have practical roles. A filler contributes bulk, a lubricant helps processing, and a release-controlling component changes how the tablet behaves in fluid. These roles differ from the biological activity of melatonin. A gummy, capsule and prolonged-release tablet need not use the same process or release melatonin at the same rate. [1]
Testing the finished product
The EMA document describes tests for identity, content uniformity, assay, microbial purity, impurities, hardness and dissolution. Stability testing also examines whether important properties remain acceptable during storage. Measuring average melatonin content is therefore only one part of quality control. [1][2]
These pharmaceutical findings cannot certify a separate supplement brand. NCCIH notes that studies of melatonin supplements have found discrepancies between labeled and measured content. A manufacturing description should be paired with evidence about the actual finished product, without treating a quality test as proof of a sleep benefit. [1][2]
Two hypothetical tablets with the same amount
Consider two tablets that each declare the same melatonin amount. One is immediate release; the other is prolonged release. Equal declared content does not establish equal release timing. A meaningful comparison would examine the formulation and dissolution evidence as well as ingredient identity and content. [1]
| Test | Question |
|---|---|
| Identity | Is the ingredient melatonin? |
| Content uniformity | Is the amount consistent between units? |
| Dissolution | How does release occur under the specified test? |
Sources for this article
- Circadin, INN-melatonin
Source consulted: 2026-09-20. This is a reference resource, not a claim that we conducted the studies or tested a product. - Melatonin: What You Need To Know | NCCIH
Source consulted: 2026-09-20. This is a reference resource, not a claim that we conducted the studies or tested a product.