Anders Behring Breivik took illegal substances to increase his physical and mental capacities on the day he launched the killing spree last July, an expert told an Oslo court Thursday. Before he launched his July 22 bomb attac on a government building in Oslo and went on a shooting rampage on Utoeya island, Breivik said he had taken an an ECA stack, a combination of ephedrine, caffeine and aspirin. This mix is illegal in Norway and the United States among other countries but is popular among body-builders and is often used for weight loss and as a stimulant. “He was slightly to moderately under the influence of a high affecting the central nervous system,” Professor Joerg Moerland of the Norwegian Institute of Public Health told the Oslo district court on the 28th day of Breivik’s trial. The 33-year-old right-wing extremist has said he took 50 percent more than the normal ECA stack dose authorised in the European Union only a few hours before his attacks. Breivik has told the court the drug cocktail allows “the brain to absorb more oxygen and this results in better physical and mental performance.”