Different types of painkiller tablets work in different ways. The three most common over-the-counter ones you’ll find are paracetamol, ibuprofen and codeine. Paracetamol works by blocking the chemical messengers in our brains that tell us we have pain. It can also reduce fever by affecting the chemical messengers that regulate your body temperature. Ibuprofen works by reducing the hormones that cause pain and swelling and is good for period pain, migraines, back pain, strains and sprains. Lastly, codeine works by stopping pain signals from travelling along the nerves to the brain. It doesn’t work really well on its own, which is why it’s often combined with ibuprofen or paracetamol in a pain relief tablet-like Co-codamol.