The National Cancer Institute defines cancer as a collection of related diseases. We know that if there are any changes in our cells’ function, such as how cells grow or divide, these changes include mutations in the deoxyribonucleic acid (DNA). From this point, a body’s cell will divide without stopping, and it will be an abnormal cell that will produce a tumor. This study has tested the hypothesis that myrrh and rosemary have compounds that will inhibit the growth of cancer cells. In this experiment, four different types of cancer cells— which are lung cancer (A549), colon cancer (SW620), breast cancer (MCF7), and cervical cancer (HeLa)—were exposed to myrrh and rosemary extractions. The alamarBlue Cell Viability assay protocol and fluorescent analysis were used to evaluate the cytoxicity of the extracts. The findings indicate that the more we have a concentration of myrrh extraction, the more we get the inhibition of lung cancer cell growth. Also, rosemary appears to inhibit cervical cancer (HeLa).