6. Insulin ($3,900 – $26,400 per liter)
Insulin is a hormone produced by the pancreas that regulates the metabolism of carbohydrates, fats and proteins by promoting the absorption of glucose from the blood. However, those suffering from diabetes often struggle to produce enough insulin, and so would need biochemically produced insulin to help meet their needs. A more affordable way to produce insulin is reportedly in development, introducing the human gene into plants to then produce it themselves.
5. Chanel No. 5 ($6,900 per liter)
Chanel No. 5 is the most expensive perfume ever made and is marketed as the flagship product that has withstood generations of rivals. It was produced in 1922 for the first time through the collaboration of chemist Ernest Beaux and Coco Chanel. Coco Chanel selected vial #5 of the samples that Beaux presented her with, due to her fondness for the number 5. The name was kept.