BACKGROUND: The selection of dermal fillers in aesthetic medicine often relies on factors such as cost, immediate outcomes, and practitioner experience. However, incorporating knowledge of fillers' rheological properties, such as viscoelasticity and cohesiveness, allows for more precise product selection tailored to patient needs and treatment goals while reducing the risk of complications. AIMS: This review aims to summarize essential considerations for filler selection, focusing on rheological properties, safety profiles, and clinical applications. Additionally, it seeks to highlight differences between hyaluronic acid (HA) fillers and non-HA fillers to guide practitioners in aesthetic procedures. PATIENTS/METHODS: A systematic review was conducted following PRISMA guidelines. Searches across PubMed, Scopus, Web of Science, and the Cochrane Library yielded 619 articles. After duplicate removal and rigorous screening, 50 peer-reviewed studies were included. Data extraction focused on filler types, rheological properties (e.g., G' and G" values), safety, and efficacy. RESULTS: HA fillers, particularly monophasic types, exhibit smoother consistency and better cohesiveness, making them ideal for high-mobility areas like the mouth. Biphasic fillers, with higher viscoelasticity, provide superior lifting capacity for deeper tissue support. Non-HA fillers, such as poly-L-lactic acid and calcium hydroxylapatite, offer longer-lasting results but require precise techniques due to irreversibility. Proper selection based on filler rheology, target area, and patient needs can mitigate risks such as overfilled syndrome, Tyndall effect, and delayed inflammatory responses. CONCLUSIONS: Understanding the rheological and safety profiles of fillers is essential for achieving optimal aesthetic outcomes. HA fillers are recommended for novice practitioners due to their reversibility, while experienced clinicians may explore non-HA options. Tailored filler selection based on rheological properties and clinical context ensures safer and more effective treatments.