ASA Effect test: An instrument to identify patients who do not respond to ASA therapy A convenient test is now obtainable in Canada that determines if the ASA a patient is taking to prevent coronary attack and stroke is working. ASA Effect is offered through LifeLabs Medical Laboratory Services and its own network of collection and testing centres http://www.tretinoincream.org/ . We’re pleased to introduce a new test that gives patients good information about the effectiveness of a medication they are taking, stated Jos Wintermans, LifeLabs CEO and president. ASA Effect offers physicians a simple tool to greatly help them identify individuals who usually do not respond to their ASA therapy. ASA, also referred to as ‘acetylsalicylic acid’, functions by making blood platelets less sticky, that may prevent blood clots from forming.