A quiet analytical research laboratory at night, racks of glass vials along a dim bench.

Sleep and Circadian Rhythm: Timing Is the Formulation

Sleep products fail on timing more than on dose. Melatonin, the core active, has a half-life under an hour and oral bioavailability near 15%, so a plain tablet peaks and clears long before morning. Controlled release is the approved answer in Europe, where prolonged-release melatonin is a prescription drug, and the design target for Vegalab's work in this area.

Circadian biology

The suprachiasmatic nucleus sets a roughly 24-hour clock that light resets each morning. In darkness, the pineal gland releases melatonin, which signals night to the body through MT1 and MT2 receptors. Sleep pressure builds separately through adenosine. Melatonin output declines with age in many people. Approved hypnotics act on other targets: GABA-A modulators, orexin receptor antagonists and the melatonin agonist ramelteon. Supplement ingredients such as magnesium, glycine and L-theanine have limited human data.

One molecule, several legal categories

Melatonin is a dietary supplement in the US and a natural health product in Canada. In the EU, prolonged-release melatonin 2 mg (Circadin) is a prescription medicine for primary insomnia in patients aged 55 and over, and national rules on food supplement doses vary. In the UK it is prescription only. A formulation built for one market may be a medicine in the next. DSIP, a research peptide, has no approved use anywhere.

The delivery problem

Oral melatonin has mean bioavailability around 15%, with wide variation, because of first-pass liver metabolism. Its elimination half-life is roughly 45 minutes. Immediate-release products therefore produce a short, high peak. Product quality is a separate problem: one analysis found melatonin content ranging from 83% below to 478% above the labeled amount. Stability, content uniformity and release profile are all formulation-controlled variables. A formulation that controls all three is more reproducible than one that only raises dose.

Key facts

Oral melatonin bioavailability averages about 15% with high interindividual variability (Harpsøe et al. 2015, Eur J Clin Pharmacol 71:901)
Prolonged-release melatonin 2 mg is authorized in the EU as a prescription medicine for primary insomnia in patients aged 55 and over (EMA EPAR, Circadin 2007)
Melatonin content in 31 supplements ranged from 83% below to 478% above label claim (Erland and Saxena 2017, J Clin Sleep Med 13:275)
Ramelteon, an MT1/MT2 agonist, is FDA approved for insomnia characterized by difficulty with sleep onset (FDA label, Rozerem 2005)

How our delivery technology applies

Melatonin is small and lipophilic enough to absorb well; the problem is timing and first-pass loss. A multi-layer shell with graded layer thickness can spread release over several hours, flattening the peak. A sublingual or buccal format with a mucoadhesive outer layer can shift part of the dose past hepatic first pass. Encapsulation also protects melatonin from light and oxidation in liquids. Release profiles are measured by dissolution testing before any claim is made.

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