Syringe attachments and syringes have particular suitability to the precision dispensing of small amounts of high viscosity materials, such as dermal fillers. An attachment may include a main body having an assist feature that includes a wheel and pinion gears on each side of the wheel which engage respective racks on the syringe body. A mechanical advantage may be provided to the user as the wheel is rotated relative to the syringe body and racks. Syringes and attachments may include precision position indicators viewed from multiple positions to enable a user to determine plunger position and the amount of dispensed contents with precision. An alternative configuration attachment may be slidably secured to a syringe to permit a user to operation the syringe from a lateral position using sliding movement of the thumb and fingers of one hand, for example. This configuration may be particularly suitable for self-administered insulin injections.