Medicine leaflets give product-specific instructions
The Circadin leaflet directs users not to use it after its expiry date and specifies storage in the original package, protected from light, below 25°C. Those details belong to that medicine. They should not be copied as the stability specification for every gummy, capsule or liquid supplement. [1]
A normal appearance does not measure potency
A bottle looking unchanged does not establish how much active ingredient remains or whether it has been stored appropriately. Conversely, the date passing does not quantify a particular toxic change. Ask the pharmacist or manufacturer about the actual preparation rather than treating an internet rule as a stability test. [1]
Do not compensate with extra servings
Imagine someone doubles an old tablet or liquid amount because they assume half the melatonin has degraded. That fraction is unknown, so the correction is invented and can increase exposure unpredictably. Use an in-date preparation that fits the treatment plan and ask a pharmacist about proper disposal of an unused medicine. [1][2]
| Situation | Response or distinction |
|---|---|
| Expired preparation | No verified remaining strength |
| Normal appearance | Not a potency test |
| Doubling the amount | Cannot correct an unknown loss |
Sources for this article
- Circadin 2 mg Prolonged-release Tablets - Patient Information Leaflet (PIL) - (emc) | 2809
Source consulted: 2026-09-20. This is a reference resource, not a claim that we conducted the studies or tested a product. - 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.