A method of delivery of a substance to a human subject's skin comprising deposition into a specific compartment of the skin, wherein the delivery occurs at a controlled rate and pressure. The methods of the invention provide accurate deposition of s pre-selected volume of the substance, e.g., greater than 90% of the pre-selected volume. The methods of the invention encompass varying one or more parameters including but not limited to configurations of the delivery device, volume, pressure, and flow rate of delivery, to enhance the efficacy of delivery of the substance to the human skin. Substances delivered in accordance with the methods of the invention result in a more efficacious deposition of the substance into the targeted compartment, improved delivery performance, i.e., completeness of delivery as measured by quantification of the substance not delivered or the amount of the substance leaked out from the injection site, and enhanced safety as measured by the occurrence of minimal adverse cutaneous events at the site of injection.