There is no direct clinical evidence or established scientific mechanism indicating that taking NAD+ supplements or precursors causes hair loss. In fact, because NAD+ supports optimal cellular repair, mitochondrial energy production, and overall tissue vitality, researchers often study it for its potential to support general follicular health. If an individual experiences hair thinning while taking a new wellness regimen, it is usually attributed to external factors such as natural genetic aging, stress, hormonal fluctuations, or concurrent nutritional deficiencies.