Well, usually street meth is racemic
Well, according to Recommended Methods For The Identification And Analysis Of Amphetamine, Methamphetamine And Their Ring-Substituted Analogues In Seized Materials by the WHO:
A. STEREOCHEMISTRY Most amphetamine type stimulants (ATS) have at least one chiral centre and can therefore be found as a racemic mixture or as individual enantiomers.* In illicit markets, most ATS are encountered Methods for the identification and analysis of amphetamine, methamphetamine in a typical stereochemical make-up. Amphetamine, for example, and most ring-substituted ATS, are typically encountered as the racemate, while methampheta-mine is frequently seen as S-, or dextro, enantiomer (also known as “Ice”, or“Shabu”), in addition to the racemate. The analysis of optical isomers is described in chapter VI.G. below
http://www.unodc.org/pdf/scientific/stnar34.pdf
Isomerism depends on the production method:
Methamphetamine is the more potent methylated derivative of amphetamine. Although it is still prescribed in its d-iso- meric form as Desoxyn illicit methamphetamine is clandes- tinely synthesized and widely abused in the United States. The /-isomeric form of methamphetamine is the active ingredient of Vick's inhalers and other nasal decongestants because it exhibits vasoconstrictive affects without the euphoria associated with the d-isomer. Illicit forms of methamphetamine will consist of either all d-methamphetamine or a racemic mixture depending on the method of synthesis (7). Clandestine manufacture of methamphetamine from the reduction of (-)ephedrine or (+)pseudoephedrine yields d-methamphetamine, whereas the production of methamphetamine from phenyl-2-propanone (P2P) and methylamine yields a racemic mixture (7)