According to the present Peruvian Criminal Code, the use and possession of drugs for personal consumption is not punished if the quantities are under the amounts stipulated by law (Art. 299: 2 grams of cocaine, 7 grams of marijuana). The problem is that almost no travelers and even very few police know this, and the police will probably still take you to the comisaría and charge you until a judge defines the amounts you carry. So to keep it safe, it is highly recommended not to take drugs while in Peru.
The penalties for smuggling out drugs are very strict for cocaine, which is common and of very high purity in Peru, and not as cut with all kinds of dangerous chemicals as in the United States and Europe. There is no bail for drug trafficking cases, and the legal process can drag on for up to two years. Your embassy will most likely decline to get involved.
Peru is well known for confidence scams that involve drugs. A typical one generally targets men and can start with a random meeting in the street with an attractive young woman. After conversation and moving to a bar or discotheque the woman will offer up some drugs. Suddenly and unexpectedly, police appear from nowhere and the attractive gal disappears.
What follows is extortion in exchange for not being arrested. The so-called “police” will explain that you could spend the next five years or more in jail unless you give them money. If you don’t react, they will take you to the police station. If you decide to offer them money, the police will drive you to a series of ATMs in order to take as much money as possible from your accounts. Several hours later, and after having your bank account cleaned out, you will probably be dropped off in some remote area of Lima. The worst part is that the perpetrators probably are not even real police.
© Ross Wehner and Renée del Gaudio from Moon Peru, 3rd Edition