This two-arm, double-blind, placebo-controlled, randomized trial evaluates the effects of Bacopa monnieri lyophilized herbal decoction (BMFD) on aging and neurocognitive function in healthy older adults with a MoCA score ≥24. Participants are randomized to receive 120 ml BMFD or placebo twice daily for 45 days, with assessments at baseline, 45 and 90 days. The study is taking place at the Clinical Trials Center at the Faculty of Indigenous Medicine, University of Colombo. Primary outcomes include telomerase activity and telomere length measured by qPCR. Secondary outcomes measure neurocognitive function (MoCA validated for the Sri Lankan population), neurophysiological function (upper and lower limb nerve conduction test, EEG) and health-related quality of life (HRQoL) with a validated questionnaire. The study integrates Ayurvedic principles including constitution (Prakriti). It is registered under the identifier ISRCTN64126920.