Their success is down to the active ingredient cytisine , which is derived from laburnum seeds .
药物疗效归功于一种有效成分金雀花碱，提取自金链花种子。
West said : " we recognise that stopping smoking can be extremely difficult and we hope that by using cytisine as a substitute for nicotine , the results of this trial could transform the health of nations around the globe by offering a practical option , even for the poorest smokers . "
