Nowadays, practicing experiments on animals has beenis one of the widely and popular methods used by the cosmetic and medicine related industries.
.... nowadays ------------> is
This sounds better had you used direct speech;
Nowadays, many cosmetic and pharmaceutical companies use animals for various experimental testing as a part of their product development research projects.By this operation, a company could test if any toxic chemicals in the products could harm people
.... you don't have to give too much details in the introduction.
Some say that testing could provide consumers with more safer and more effective products.
While both sides seem reasonable, prohibiting animal testing should be justified.
Make a clearer statement to express your opinion;
Although both arguments have valid points, I personally believe that using for animals for experimenting is not ethical and should be avoided.