The Effect of a Daily Magnesium and Melatonin Supplement on Sleep Quality in People With Nighttime Leg Cramps

Inclusion Criteria:

* Adults aged 40-75 years
* Self-reported poor sleep quality (PSQI \>5) at screening
* Self-reported nocturnal leg cramp averaging ≥4 episodes per fortnight at screening
* Capacity to understand and provide electronic informed consent
* Willing to wear an Oura Ring wearable device continuously throughout the study period
* Access to a smartphone/tablet with iOS 15 or higher and Android 9 or higher and willing to install and use the Oura and Trialflare applications
* Be a resident of and permanently living in Florida with no planned travel across more than one time zone for at least 1 night during the study period

Exclusion Criteria:

* Current or recent (within 4 weeks of randomisation) use of melatonin, magnesium, or other supplements specifically taken for sleep or leg cramps or listed as an ingredient of the intervention supplement.
* Current use of any prescription medication
* Diagnosed sleep disorder (e.g. obstructive sleep apnoea, restless legs syndrome, insomnia disorder)
* Known or suspected secondary cause of nocturnal leg cramps (e.g. peripheral vascular disease, neurological condition, renal impairment, thyroid disorder)
* Any current or prior diagnosis of:
* Cancer or malignancy of any kind (prior malignancy is not exclusionary if the participant is in confirmed remission and has completed all treatment)
* Cardiovascular disease (e.g. hypertension, coronary artery disease, heart failure, arrhythmia, stroke, peripheral vascular disease)
* Autoimmune disorder (e.g. rheumatoid arthritis, lupus, multiple sclerosis)
* Gastrointestinal disorder (e.g. IBS, malabsorption syndromes)
* Neurological disorder (e.g. epilepsy, Parkinson's disease, dementia)
* Hepatic or renal impairment
* Diabetes mellitus (type 1 or type 2)
* Severe psychiatric disorder (e.g. schizophrenia, bipolar disorder)
* Myasthenia Gravis
* Known hypersensitivity or allergy to any ingredient in the active or placebo product
* Rotating shift work or irregular sleep patterns
* Current participation in another interventional clinical trial
* Inability to comply with study procedures or remote visit schedule
* Breastfeeding, pregnant, or planning to become pregnant during the study period