The pharmaceutical industry is vital for healthcare advancement through innovative medications, improving lives. A substantial challenge is "Drug lag," hindering patient access and increasing disease adjusted life years burdens. We aim to examine drug lag for Iran Food and Drug Administration (IFDA) approved drugs versus US Food & Drug Administration (FDA), European Medicines Agency (EMA), and Pharmaceuticals and Medical Devices Agency (PMDA) over 2001 to 2021. We reviewed new molecular entities within this period, using descriptive statistics in Excel 2019. Drug lag is assessed from relative and absolute perspectives, considering approval gaps and annual rates. Among 710 FDA-approved drugs, 410 received EMA approval, 344 from PMDA, and 148 from IFDA. For 148 IFDA and FDA-approved drugs, the maximum drug lag was 237 months. The mean relative drug lag was 65.18 ± 61.56 months. Compared to EMA (112 drugs), the maximum lag was 257 months, with a mean relative lag of 70.29 ± 53.67 months. With PMDA (127 drugs), the maximum lag was 253 months, with a mean relative lag of 38.23 ± 60.57 months. Iran faces significant drug lag compared to developed countries' regulatory bodies, limiting patient access to innovative treatments. Addressing this issue is crucial for timely drug access, reducing disease burdens. Further research and policy interventions are needed to mitigate drug lag's impact on Iran healthcare landscape.