OBJECTIVES: Reference pricing (RP) – an approach where a payer sets payment for a group of similar drugs using benchmark based on a lower-priced option is a strategy commonly used to control drug expenditures. The aim of this study was to determine the impact of Polish human insulin (Gensulin, BIOTON) on public payer’s expenditure in 2001-2013. METHODS: We analyse published data on insulin consumption and changes in reimbursement limits between October 2001 and February 2013. An Excel-based model was developed to compare scenario with (1) and without (2) Gensulin on the Polish pharmaceutical market. The reimbursement limit for insulin in (1) was determined by Gensulin (the lowest priced product within a group of human insulins),  in (2) was fixed at 151 PLN/1500 i.u (A) or decreased to 134.99 from April 2002 (B). In the calculation all products containing 1500 i.u.insulin/pack or only pen were considered. Cost was adjusted for inflation and reported in PLN at 2013 prices (1 Euro=4.2 PLN). Results were presented as total and incremental cost in subsequent years and over the entire period. RESULTS: Between 2002-2012 the consumption of human insulins in Poland incresead from 3.8 mln to 5.6 mln pack a 1500 i.u. The reimbursement limit in PLN/pack decreased gradually from 151 in 2001 to 98.57 in 2013 (scenario 1). Overall for the 12.5-year period the total public payer savings resulting from setting the reimbursement limit by Gensulin  were 3 157 114 474 and 2 039 163 591 PLN in A and B, respectively. If only pens were considered RP policy led to a saving of 2 719 053 565 PLN in (A) and 1 777 711 973 PLN in (B) over 12.5 years.  CONCLUSIONS: The launch of Gensulin and RP resulted in considerable reduction of public resources spent on human insulin in Poland