Buying Tramadol online, Tramadol is a strong opioid medication used to treat moderate to severe pain. It works by reacting with brain opioid receptors, affecting serotonin and norepinephrine intake. Serious side effects include serotonin increase and addiction. Common side effects include constipation, nausea, and skin itching. People with liver or kidney problems, those at increased risk of suicide, and breastfeeding women should not take this medication without medical supervision.