Methamphetamine & Amphetamine
Synthesis Route
The dominant illicit route in North America is the HI/red phosphorus reduction of pseudoephedrine (the "Nagai reaction"). Pseudoephedrine is reduced with hydroiodic acid and red phosphorus to produce methamphetamine (Skinner, 1990; Windahl et al., 1995).
Other routes:
- Birch reduction — anhydrous ammonia and lithium metal
- P2P reductive amination — uses phenyl-2-propanone; produces racemic d/l-methamphetamine and now dominates cartel-scale Mexican production
Predictable Synthesis Byproducts
Present in most clandestine methamphetamine, varying by route — baked in, not cut:
- Phosphorus residues — red and white phosphorus, phosphine gas byproducts. White phosphorus is acutely toxic.
- Iodine compounds — residual HI, iodoephedrine, iodine salts.
- Phenyl-2-propanone (P2P) — intermediate; sometimes survives in trace amounts.
- N-formylmethamphetamine, N-acetylmethamphetamine — byproducts characteristic of the synthesis route (Windahl et al., 1995).
- cis-cinnamoyl methamphetamine — characteristic of the HI/P route.
- Lead contamination — historically documented when methylamine was sourced from lead-containing reagents; rare now.
- Solvent residues — toluene, acetone, ether.
Typical Adulterants
Crystalline methamphetamine ("crystal," "ice") is less cut than cocaine — it is hard to dilute crystal without it being obvious, so most crystal meth is relatively unadulterated. The synthesis byproducts above are the main contaminants. Powder methamphetamine is cut more often.
| Adulterant | Est. probability | Risk |
|---|---|---|
MSMmethylsulfonylmethane — dietary supplement |
High in crystal | Mostly inert bulk filler; closely resembles meth crystals visually |
Dimethylsulfone |
Moderate | Generally inert bulking agent |
Caffeine |
Moderate — ~15–30% of powder | Cardiac stress |
Ephedrine / pseudoephedrinefrom incomplete reactions |
Low — trace level | Cardiovascular stress |
Fentanyl |
Low in crystal (<1%); higher in powder — ~12–15% in some US regions (Lambdin et al., 2023) | Fatal respiratory depression |
Lead |
Very low — historically documented | Heavy metal poisoning, neurological damage |
Removal & Testing
Recrystallization — dissolving in a polar solvent then a non-polar solvent — does remove some differentially soluble bulking agents (MSM, caffeine). It does not remove synthesis byproducts integrated into the crystal lattice. It is partial filtering, not purification.
- Fentanyl test strips — essential for powder meth; increasingly recommended for crystal in documented-contamination regions. A negative test does not guarantee absence.
- Reagent kits — Marquis turns orange-brown for meth; Simon's reagent distinguishes meth from MDMA. These confirm identity, not purity.
Sources: Full references for the citations in this submodule (Skinner, 1990; Windahl et al., 1995; Lambdin et al., 2023) are listed in the Module 10 Sources section.