OBJECTIVE An analysis of the impact of the commercialisation of intranasal administration on calcitonin consumption. METHODS Descriptive study. METHODS Non-hospital ambit within the national health system. METHODS A protected population group within the national health system, with occupationally active people and pensioners being differentiated. METHODS Commercialisation of a new way of administering calcitonins in March 1992. RESULTS The consumption of calcitonins dispensed in prescriptions by the national health system was differentiated according to methods of administration; calculations being made for the number of containers, cost and daily dosage defined (DDD) by population groups (overall and pensioners) and for the distribution of consumption for Autonomous Communities in DDD per 1,000 inhabitants and per day. In 1992 123% more containers and 47.29% more DDD of calcitonins were used than in 1991. In February 1993, DDD consumption of calcitonins intranasally was twice the parenteral consumption. Pensioners consumed 77.63% of the DDD of parenteral calcitonins, compared with the active population; and 71.78% compared with intranasally taken calcitonins. CONCLUSIONS The market introduction of intranasal methods has led to a notable increase in calcitonin consumption. Intranasal methods make up an ever-growing percentage of consumption and reached double the parenteral consumption in February 1993. By population groups, it was observed that pensioners used parenteral more than intranasal methods.