Elevated blood pressure (BP) is a key modifiable cardiovascular risk factor. In low-risk individuals, guidelines recommend lifestyle interventions before pharmacotherapy. Evidence for magnesium taurate-potassium citrate supplementation in this setting is lacking. This prospective, single-arm observational study enrolled 121 adults with elevated BP or stage 1 hypertension and low cardiovascular risk (SCORE2/SCORE2-OP), per 2024 ESC guidelines, who declined antihypertensive drugs. All received lifestyle counselling plus magnesium taurate-potassium citrate (121 mg elemental magnesium, 180 mg elemental potassium daily) for three months. The per-protocol cohort included 110 patients. Primary outcomes were BP changes at work, at home (HBPM), and ambulatory BP (ABPM). Secondary outcomes were pulse-wave velocity (PWV), augmentation index (AIx), renal function, and serum electrolytes. At three months, BP at work fell by -12/-9 mmHg, HBPM by -11/-8 mmHg, and ABPM by -11/-8 mmHg (all p<0.001). PWV and AIx improved by -0.9 m/s and -4.0% (p<0.001). Serum magnesium rose by +0.1 mg/dL (p=0.003) without changes in sodium, potassium, or renal function. No serious adverse events occurred. In low-risk adults with elevated BP, magnesium taurate-potassium citrate plus lifestyle advice significantly reduced BP and arterial stiffness over three months, supporting magnesium taurate-potassium citrate as a safe non-pharmacological option. As this was a single-arm observational study with routine lifestyle counselling, causal inference was limited, underscoring the need for randomized trials.