Objective: To investigate the anti-cancer effect of frankincense derived heavy oil obtained by Soxhlet extraction method on breast cancer cells(MDA-MB-231), and to study its chemical profile using gas chromatography mass spectrometry analysis.Methods: Hexane was used to extract heavy oil from frankincense resin. Chemical profiling of heavy oil was done using Perkin Elmer Clarus GC system with mass spectrometer. MDA-MB-231 cells were treated with different dilutions(1:1 000, 1:1 500,1:1 750, 1:2 000, 1:2 250, 1:2 500, 1:2 750, 1:3 000, 1:3 250) of heavy oil for 24 h. The cells were observed by using light microscopy. Cell viability was measured by MTT assay.Results: Gas chromatography mass spectrometry chemical profiling of frankincense derived heavy oil revealed the presence of terpenes such as a-pinene(61.56%), a-amyrin(20.6%), b-amyrin(8.1%), b-phellandrene(1.47%) and camphene(1.04%). Heavy terpene cocktail induced significant MDA-MB-231 cell death at each concentration tested. Noticeably, very low concentration of Soxhlet derived heavy terpenes elicits considerable cytotoxicity on MDA-MB-231 cells compared to hydro distillated essential oil derived from frankincense resin.Conclusions: Extracting anti-cancer active principle cocktail by simple Soxhlet method is cost effective and less time consuming. Our in vitro anti-cancer data forms the rationale for us to test heavy terpene complex in breast cancer xenograft model in vivo. Furthermore, fractionation and developing frankincense heavy terpene based breast cancer drug is the major goal of our laboratory. Objective: To investigate the anti-cancer effect of frankincense derived heavy oil obtained by Soxhlet extraction method on breast cancer cells (MDA-MB-231), and to study its chemical profile using gas chromatography mass spectrometry analysis. Methods: Hexane was used to Chemical heavy crude was was used in a Perkin Elmer Clarus GC system with mass spectrometer. MDA-MB-231 cells were treated with different dilutions (1: 1000, 1: 1 500, 1: 1 750 1: 2 250, 1: 2 500, 1: 2 750, 1: 3 000, 1: 3 250) of heavy oil for 24 h. The cells were observed by using light microscopy. Cell viability was measured by MTT assay. Results: Gas chromatography mass spectrometry chemical profiling of frankincense derived heavy oil revealed the presence of terpenes such as a-pinene (61.56%), a-amyrin (20.6%), b- amyrin -phellandrene (1.47%) and camphene (1.04%). Heavy terpene cocktail induced significant MDA-MB-231 cell death at each concentration tested. eably, very low concentration of Soxhlet derived heavy terpenes elicits impart cytotoxicity on MDA-MB-231 cells compared to hydro distillated essential oil derived from frankincense resin. Conclusions: Extracting anti-cancer active principle cocktail by simple Soxhlet method is cost effective and less time We have in vitro anti-cancer data forms the rationale for us to test heavy terpene complex in breast cancer xenograft model in vivo. Furthermore, fractionation and developing frankincense heavy terpene based breast cancer drug is the major goal of our laboratory.