To raise money for his research, Horrobin left academia and in 1977 established a company called Efamol to sell evening primrose oil (EPO) as a proposed treatment for various ailments. For example, Horrobin considered EPO to be a treatment for eczema "after trying it on the son of a librarian from his college". Horrobin planned to use the profits from Efamol to fund research and development of drugs containing EPO fatty acids.
Horrobin's decision to leave academia and start a company to sell evening primrose oil (EPO) highlights his entrepreneurial spirit and desire to fund further research on its potential medicinal properties. He aimed to use the profits from this venture to support his ongoing research into EPO-based drugs.