Dextromethorphan is a common cough suppressant that is found in more than 120 cold medications that are sold over the counter. In some cases, dextromethorphan is sold alone. In other cases, it can be combined with a wide variety of other treatment options for the common cold including expectorants, decongestants, and antihistamines. Dextromethorphan is also commonly used as a recreational substance because it can cause visual and auditory hallucinations, causing people to feel a euphoric sensation. Some of the most common names for dextromethorphan recreational use include skittling, dexing, and robo-tripping. Dextromethorphan is sold as capsules, tablets, and cough syrup, but it can also be found as a powder over the internet.