DXM is fun, but stupid, but if you must how is some info. Yes, cough syrup is the best way other then getting pure DXM because the cough syrup only has DXM as active. The trip is different everytime about (for me anyways), it last for 5 to 8 hours depending on dose, side effects include trouble peeing, burning skin, itchy skin. Don't do too much as it could be dangorous, so start out on just one 4 oz. bottle of Robitussin Maximum Strength Cough and make sure thats what you get. Drink, lay down for about an hour and enjoy.