Background: Inhaled insulin has proven to be viable and, in some aspects, a more effective alternative to subcutaneous insulin. Past and present insulin inhaler devices have not found clinical or commercial success. Insulin inhalers create a dry powder or soft mist insulin aerosol, which does not provide the required uniform particle size or aerosol volume for deep lung deposition. Methods: The primary focus of this review is to investigate the potential treatment of diabetes with a wet insulin aerosol. Vibrating mesh nebulisers allow the passive inhalation of a fine wet mist aerosol for the administration of drugs to the pulmonary system in higher volumes than other small-volume nebulisers. Results: At present, there is a significant focus on vibrating mesh nebulisers from the pharmaceutical and biomedical industries for the systemic administration of pharmaceuticals for non-traditional applications such as vaccines or the treatment of diabetes. Systemic drug administration using vibrating mesh nebulisers leads to faster-acting pharmaceuticals with a reduction in drug latency. Conclusions: Systemic conditions such as diabetes, require the innovative development of custom vibrating mesh devices to provide the desired flow rates and droplet size for effective inhaled insulin administration.