Most methamphetamine used in the United States is manufactured in Mexico by transnational criminal organizations, using precursor chemicals largely sourced from China. But the full picture spans more than a century of chemistry, multiple continents, and production methods ranging from massive industrial labs to improvised operations in soda bottles.
The Original Synthesis
Methamphetamine was first synthesized from ephedrine, a natural stimulant found in the ephedra plant, by Japanese chemist Nagayoshi Nagai in 1893. In 1919, another Japanese chemist, Akira Ogata, crystallized methamphetamine hydrochloride, producing a more stable form that could be easily administered. That crystallized version is essentially the same compound that exists today, both in its rare pharmaceutical form and in the illicit supply.
Pharmaceutical methamphetamine still exists under the brand name Desoxyn, approved by the FDA to treat ADHD in children ages 6 and older. It is manufactured by Ajenat Pharmaceuticals, but it is rarely prescribed and plays virtually no role in the current drug crisis.
How Illicit Meth Is Made
There are two main chemical pathways used to produce methamphetamine illegally, and they yield different products.
The pseudoephedrine reduction method starts with pseudoephedrine or ephedrine, the active decongestant in many cold medications. The process uses combinations of chemicals like red phosphorus and iodine, or anhydrous ammonia and lithium metal, to strip an oxygen molecule from pseudoephedrine and convert it into methamphetamine. This method produces a more potent form of the drug. Laws restricting the sale of pseudoephedrine in the mid-2000s were specifically designed to cut off this supply chain.
The P2P method (named after the chemical phenyl-2-propanone) uses an entirely different starting material. Instead of cold medicine, it relies on industrial chemicals: phenyl-2-propanone, aluminum, methylamine, and mercuric chloride. This method produces a slightly different version of the molecule, a 50/50 mix of two mirror-image forms rather than the single potent form from pseudoephedrine. Mexican cartels have largely shifted to the P2P method because its precursor chemicals can be purchased in bulk from overseas suppliers, bypassing pseudoephedrine restrictions entirely.
Mexico and the Chinese Chemical Pipeline
Mexican transnational criminal organizations produce the vast majority of methamphetamine consumed in the United States. According to the DEA’s 2025 National Drug Threat Assessment, Mexican-produced meth dominates the U.S. market, with most of it entering the country at the southwestern border.
The supply chain starts further away than Mexico, though. Roughly 80 percent of the precursor chemicals used in Mexican meth labs originate in China. These chemicals are shipped from China to Mexico and Central America, where they are processed into finished methamphetamine, then transported overland into Texas, Arizona, and California. From those entry states, it is distributed across the country. Mexican drug trafficking organizations typically use commercial trucks and private or rental vehicles to smuggle the drug through the 25 land ports of entry along the Southwest Border, as well as through remote stretches of desert and mountainous terrain between those checkpoints. Maritime smuggling of meth is rare.
Southeast Asia’s Golden Triangle
Mexico is the primary source for the U.S. market, but it is not the world’s only major production hub. The Golden Triangle, particularly Shan State in Myanmar, has become the center of an enormous methamphetamine manufacturing operation serving East and Southeast Asia.
Production in Shan State has increased significantly since 2021, and the scale is staggering. Law enforcement across East and Southeast Asia seized a record 236 tons of methamphetamine in the most recent reporting period, a 24 percent increase over the previous year. Thailand, the main transit and destination point for meth trafficked from Myanmar, recorded seizures that included one billion tablets of yaba, a combination of methamphetamine and caffeine sold cheaply across the region. Trafficking corridors connecting Myanmar to Cambodia through Laos have expanded rapidly, and maritime routes linking Malaysia, Indonesia, and the Philippines are growing in significance.
Small-Scale Domestic Labs
While large-scale foreign production dominates the U.S. supply, some methamphetamine is still made domestically in small, improvised operations. The most common is the “one-pot” or “shake and bake” method, which combines pseudoephedrine from cold medicine packets with lithium strips from batteries, ammonium nitrate from cold packs, camp fuel or lighter fluid as a solvent, and household drain opener (lye). Everything goes into a sealed plastic soda bottle, where the chemical reaction takes place.
These labs are extremely dangerous. The reaction builds pressure inside the sealed container and can cause a violent explosion if the bottle is disturbed or opened, exposing the contents to oxygen. The process also releases harmful toxic gases. One-pot labs are typically identified by the presence of emptied cold medicine blister packs, stripped batteries, coffee filters stained with residue, and soda bottles containing white crystalline material. They can be set up in a car, a backpack, or a motel room, making them difficult for law enforcement to detect in advance. Despite their visibility in public awareness campaigns, these small labs produce only a tiny fraction of the methamphetamine circulating in the United States compared to the industrial-scale operations in Mexico.