Methamphetamine, also known as crystal meth and colloquially as "tina", was a psychoactive stimulant often used as a recreational drug.
Various methods existed for synthesizing methamphetamine, one of which used methylamine as a precursor. (Underground #1)
Karma was a potent "super" methamphetamine variant that induced euphoria and mild hallucinogenic effects in the user. According to the DEA, if unchecked the drug could cause an epidemic on the scale of the crack cocaine epidemic of the 1980s. (Trojan Horse)
Viktor Grigorin was charged with possession and distribution of methamphetamine, and served a combined fourteen-year sentence in Krudonsk Pentitentiary. ("Day 5: 4:00pm-5:00pm")
Before Day 1, Jack Bauer was forced to go undercover as a drug distributor and recover a meth shipment manufactured by Sergei Petrenko's crime syndicate. (Chaos Theory)
