Why might people be against using stem cells from embryos?

People might be against using stem cells from embryos due to ethical concerns surrounding the status of the embryo, which some view as a potential human life. This perspective often stems from religious or moral beliefs that prioritize the sanctity of life. Additionally, opponents may worry about the implications of manipulating human embryos and the potential for misuse in cloning or genetic engineering. These concerns can lead to significant public and political debate over stem cell research policies.