Endometriosis is a common women health disorder that occurs when Endometrial-like tissue grows outside the uterus. This may lead to irregular bleeding , pelvic pain, infertility and other complications.   Metformin,  because of its activity to improve  insulin sensitivity, it is  used for  the treatment of diabetes; it  also  has a modulatory  effect  on  ovarian  steroid  production and has  anti-inflammatory  properties,  all may  suggest  its possible effect in treatment  of endometriosis. This  study  was  planned  to  determine  the  effect  of  metformin  on serum levels  of  interleukin- eight(IL-8),  Tumor  necrosis  factor-alpha (TNF –α)  and estradiol (E2)  production , and  related  symptomatic  changes  that  accompany  with endometriosis  (pelvic  pain,  dysmenorrhea  and  menorrheaga)  after  three months of study. Blood samples were obtained from those taking  metformin and measure the serum levels of (IL-8) , TNF –α and (E2) were measured before and after three months of taking a  metformin .Metformin  therapy  resulted  in  a  significant  reduction  in  the  clinical symptoms  of  endometriosis  (pelvic  pain  and  dysmenorrhea)  and insignificant changes in menorrhagia. Metformin therapy resulted in a  significant  reduction  in the serum levels of  IL-8,  TNF-  α while  insignificant  reduction  in  estradiol  E 2  in  the  study  group after 3 months of treatment .In conclusion the results of this study, demonstrated that metformin may be a well-tolerated  treatment  for  endometriosis  that  relieved  pain  and reduces  menstrual disorders and serum  levels  of  the  inflammatory  markers  (IL-8  and  TNF-α)  are decreased  in study  group treated  with metformin after 3 months due to its   anti-  inflammatory effects.

Keywords: Endometriosis, Metformin, TNF – a ,IL-8, E 2.