Illegal Drugs — México
México has an abundance of naturally occurring psychoactive plants that indigenous people have used in ritual for thousands of years. The two most common are Peyote cactus and Psilocybin mushrooms. Both are powerful hallucinogens. Peyote has been used for at least five thousands years in central and northern México and the Desert Southwest of the US. Psilocybin mushroom use has been dated as far back as 200 AD, mostly in the south and central regions of the country. Possession of either plant is illegal. The police generally tolerate traditional use by indigenous Méxicans, non-indigenous Méxicans and foreigners are prosecuted.
Marijuana (mota) is not native to México and has no ritual use in any indigenous cultures. Used widely by Méxicans as a recreational drug, it is illegal and penalties are severe for possession of amounts greater than the legal limit for personal use. Even though it is not native plant, marijuana thrives in México, and is grown mainly in the Pacific coast states of Sinaloa, Michoacán, Guerrero, and Oaxaca and in the Yucatán peninsula. The primary growers are well organized and heavily armed crime syndicates looking to export to the US. As an illegal cash crop marijuana is highly lucrative. This has made México a major battleground for the US government in its ill-conceived War on Drugs.
Cocaine use and smuggling are a huge national problem in México. Use of powder cocaine is widespread and growing. Crack has taken hold in México City and northern border cities. Both forms are illegal and penalties are severe for possession of amounts greater than the legal limit for personal use. Partnering with Méxican crime syndicates, Colombian cocaine cartels have made México a major transshipment point in moving their product to US markets. This is a serious problem for the Méxican government. As the crime syndicates become more powerful they pose a challenge to the authority of local governments, especially in Guadalajara and the border cities of Ciudad Juárez and Tijuana.
In August 2009 México decriminalized possession of small amounts of drugs for personal use. The new law sets out maximum amounts for personal use: marijuana, 5 grams — about four joints; cocaine, 0.5 grams — about 4 "lines"; LSD, 0.015 milligrams; methamphetamine, 40 milligrams; and heroin, 50 milligrams. Anyone caught with drug amounts under those limits no longer faces criminal prosecution. For the first two possession charges users are encouraged to seek drug treatment. After a third charge drug treatment is mandatory.
This new approach represents a significant change from the zero tolerance policy and harsh sentences for personal use México has pursued at the insistence of the US government. Rather than act as a deterrent, the previous harsh sentences enabled corrupt police to shake down casual users and addicts for bribes by threatening long prison sentences if they didn't pay up. Decriminalizing personal use should give the accused greater legal protection.
Illegal drug use is the main reason foreigners have serious trouble with the police and possession of amounts greater than the legal limit for personal use are aggressively prosecuted and penalties are severe. Méxican law does not distinguish between the possession of marijuana and harder drugs like cocaine and the same harsh penalties apply. Persons convicted of smuggling drugs face long prison sentences. Claiming ignorance of Méxican law will get you nowhere. There is little your embassy or consulate can or will do beyond helping find an English speaking lawyer and acting as a intermediary with family or friends back home.
Because they pose a flight risk foreigners are never released on bail, even for minor possession charges. If you are eventually found innocent you could still find yourself in a Méxican jail for a long time until your case is heard and a verdict is reached.
The bottom line — it's not worth it.