A con of gmos is that? Is the answer there is a inefficient research to know the long term impacts they have?

Yes, that is one potential con of GMOs. The long-term impacts of genetically modified organisms (GMOs) are not yet fully understood, and there is ongoing debate and insufficient research regarding their potential effects on human health and the environment. This lack of knowledge raises concerns for some people who prefer to err on the side of caution when it comes to introducing genetically modified crops and organisms into the ecosystem.