Inhaled insulin (Exubera; Pfizer) was launched in the UK in August 2006. It is a dry-powdered, human, regular insulin that is made into an aerosol mechanically by a handheld device at the time of inhalation. The powder is prepackaged in 1mg and 3mg foil packets that deliver the equivalent of around three and eight units of insulin. The large surface area of the lung enables the large insulin molecule to cross from the alveoli by transcytosis. It is then released and taken up by endothelial cells to be released into the bloodstream.