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