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The main thing about P2P meth is that there's so much of it

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The main thing about P2P meth is that there's so much of it

dynomight ·<br>updated Aug 2022

science

policy

Sam Quinones was recently on Econtalk and in the Atlantic talking about methamphetamines and homelessness. He points out that “old” meth was made from ephedrine and that “new” meth is made from a chemical called Phenylacetone or P2P. He suggests that new meth might be chemically different in a way that caused people to go crazy, starting around 2017:

Ephedrine meth was like a party drug. […] You could normally kind of more or less hang onto your life. You had a house, you had a job. […] P2P meth was nothing like that. It was a very sinister drug. It brought you inside. You didn’t want to be around other people. You wanted to just kind of be alone with whatever bizarre thoughts your mind was now cooking up, and conspiracies.

I was curious about this. What do we know about the difference between old meth and P2P meth? What evidence is there that these have a chemical difference?

Meth in the US shifted to P2P synthesis between 2009 and 2012.

In the before times, meth was made with ephedrine or pseudoephedrine. However, in 2006, the US banned over-the-counter sales of pseudoephedrine, and in 2008 Mexico banned almost all sales. In response to this, meth makers switched to a synthesis based on P2P, which can be made from many different, widely available, source chemicals.

The Drug Enforcement Agency tests the meth they seize to see how it was made. Here’s their data starting in 2009, where you can see that P2P synthesis (in red) rapidly displaces the older ephedrine-based synthesis (in blue).

How could P2P meth be different? There are two ways: Either it could be a different type of meth, or the meth could be contaminated with some other chemicals.

Let’s talk about different types of meth first.

Isomers

A naive P2P synthesis would produce an even mixture of l-meth and d-meth.

For many complex molecules, you can take the atoms, and “flip” them to get another stable version of the same molecule, called an isomer or (more specifically) an enantiomer. These different versions of the molecule can have very different effects on the body.

Methamphetamine happens to be one of those molecules. The one that produces the effects we call “meth” is d-methamphetamine (d-meth). That’s the one that increases dopamine in the brain, causing euphoria. (It’s also the one that is sold at pharmacies in the US to treat ADHD and obesity.) On the other hand, l-methamphetamine (l-meth) has no effects on dopamine and presumably isn’t nearly as much fun.

Anyway, a synthesis that turns P2P into meth will create an equal mixture of d-meth and l-meth, basically because atoms bouncing around randomly are equally likely to end up in either of two equally low-energy configurations. Older synthesis methods using ephedrine would create only d-meth.

P2P initially had a fair amount of l-meth, but it was almost all gone by 2019.

Here’s data from the DEA again, where “potency” is the percentage of d-meth among all meth. This data is assembled from the National Drug Threat reports from many different years:

Be careful here: Take a sample of meth that’s ¼ d-meth, ¼ l-meth, and ½ other impurities. This would count as 50% potent because 50% of the meth is d-meth. (Other impurities are accounted for with “purity” below.)

The dip in 2014 might be explained by the introduction of a new synthesis method (NTS), which we’ll talk about below.

Unfortunately, I can’t seem to find any data going back further to before when P2P meth was introduced. It’s likely that d-meth was higher before P2P synthesis become popular, though this paper analyzes meth in Australia and finds that, for some reason, ephedrine-based meth often has fair amounts of l-meth, too.

L-meth is in various easy-to-obtain drugs.

Vick’s VapoInhalers contain 50mg of l-meth, which they spell in an unusual way probably to reduce the number of people who notice what’s in there and freak out.

L-meth is also produced as a metabolite of Selegiline, a drug for Parkinson’s and depression.

Contaminants

The purity of meth is now higher than ever.

The DEA has tracked purity in meth that they have seized for a long time. They define purity to be the percentage of meth (d or l) amongst all chemicals in the sample. Here’s a plot of all the data I could find:

Now, the terms “purity” and “potency” as used by the DEA are a bit confusing. A consumer of meth probably cares about the percentage of d-meth amongst all chemicals in the sample. You get this by multiplying the purity and potency:

Modern street meth is higher quality than ever, around 95% d-meth on average.

There are many ways to make P2P meth.

Here’s a figure that shows how P2P might be produced from source chemicals, simplified from this paper:

This shows two routes to make P2P. The top route uses benzaldehyde and nitroethane to produce...