Under a new law that came into effect this week, drug users can possess a greatly increased amount of an illegal substance -- for instance, 20 grams of marijuana or 1.5 grams of cocaine -- without the risk of being thrown in jail.

The law has been criticized by the Federal Anti-Drug Service, which says it hampers the battle against drugs, but praised by those who work to rehabilitate drug addicts, who predict more addicts will now seek help.

President Vladimir Putin signed an amendment to the Criminal Code in December stipulating that possession of no more than 10 times the amount of a "single dose" would now be considered an administrative infraction rather than a criminal offense. Punishment would be a fine of no more than 40,000 rubles ($1,380) or community service.

It then took five months to hammer out what would be considered the single dose of various drugs.

Ten times the amount of a single dose, as set in the government resolution that came into effect Wednesday, is 20 grams of marijuana, 5 grams of hashish, mescaline or opium, 1.5 grams of cocaine, 1 gram of heroin or methamphetamine, and 0.003 grams of LSD.

Anyone caught in possession of these amounts or less cannot legally be detained, a spokeswoman for the Moscow branch of the Federal Anti-Drug Service said. Instead, a report will be filed and the fine will be determined by a court.