Cannula is safer than needle in filler injection?

The choice between cannulas and needles for dermal filler injection has direct implications for safety, efficacy, and patient experience. This narrative review synthesizes evidence from randomized controlled trials, observational studies, cadaveric/anatomical work, and expert consensus to compare complication profiles and practical use-cases. Across multiple studies, cannulas-by virtue of their blunt tips and gliding technique-are associated with lower rates of bruising and a reduced signal for vascular occlusion in high-risk, vessel-dense regions, while also improving patient comfort and downtime. However, cannulas are not inherently risk-free: arterial wall penetration and ischemic events remain possible with improper plane selection, excessive injection pressure, or inadequate anatomical control. Needles retain advantages for precise, focal periosteal or ligamentous support and for select micro-bolus indications. Publication bias and heterogeneous endpoints likely underestimate true complication rates for both devices. Guided by anatomy and procedural goals, a tailored approach is recommended: preferential cannula use for broad, low-pressure distribution in vessel-dense areas; needle use for targeted structural points with strict low-volume, low-pressure technique. Ultrasound guidance further enhances plane confirmation and vascular avoidance. We conclude that device selection should be individualized to region, indication, and operator skill, coupled with slow injection, minimal aliquots, and ongoing training to optimize patient safety and outcomes.