ELI5 How does medicine like antibiotics know where to go in our body
They don’t. They go everywhere in the body. So we have to make medications so that they only affect certain types of cells in the body. For example bacteria have cell walls and our body cells don’t. So one type of antibiotics attacks all cells with a cell wall – thereby killing the bacteria.
Chemicals in medication bind to specific receptors, so other parts of the body won’t be affected if they don’t have those receptors. However, a lot of medications do affect other parts of the body – targeting only specific areas is pretty difficult – causing the side effects.