In 1935, clinical trials of safer purified heparin began in Toronto after work at Connaught Laboratories. By 1937, heparin was shown to be safe, available and effective as a blood anticoagulant. These trials turned heparin from a laboratory curiosity into a practical lifesaving medicine.

The first clinical trials of purified heparin in 1935 marked a significant advancement in medical treatment, allowing survival after clots and dangerous operations. The cultural implications of this breakthrough were profound, enabling more people, including artists and poets, to continue their creative journeys.