A study was performed in Iran and published in the Eastern Mediterranean Health Journal (2006; 12(3-4):423-7). It compared mefenamic acid to fennel for the treatment of dysmenorrhea pain. Memfenamic acid is a non-steroidal anti-inflammatory drug used to treat pain, including menstrual pain. Two groups of high school girls were selected randomly to receive either a fennel extract or memfenamic acid for a period of two months. The fennel performed well in comparison to the drug, 80% of the girls experienced either reduction in pain or complete pain relief, compared to 73% of the group receiving the drug. Also, 80% of the girls in the group receiving the fennel no longer felt the need to rest, compared to 62% in the group receiving the drug.