Via BoingBoing, a paper accepted to the Journal of Apocryphal Chemistry by researchers from Miskatonic University: “A Simple and Convenient Synthesis of Pseudoephedrine From N-Methylamphetamine“.

Pseudoephedrine, active ingredient of Sudafed®, has long been the most popular nasal decongestant in the United States due to its effectiveness and relatively mild side effects. In recent years it has become increasingly difficult to obtain psuedoephedine in many states because of its use as a precursor for the illegal drug N-methylamphetamine (also known under various names including crystal meth, meth, ice, etc.). While in the past many stores were able to sell pseudoephedrine, new laws in the United States have restricted sales to pharmacies, with the medicine kept behind
the counter. The pharmacies require signatures and examination of government issued ID in order to purchase pseudoephedrine. Because the hours of availability of such pharmacies are often limited, it would be of great interest to have a simple synthesis of pseudoephedrine from reagents
which can be more readily procured.

A quick search of several neighborhoods of the United States revealed that while pseudoephedrine is difficult to obtain, N-methylamphetamine can be procured at almost any time on short notice and in quantities sufficient for synthesis of useful amounts of the desired material. Moreover, according to government maintained statistics, Nmethylmphetamine is becoming an increasingly attractive starting material for pseudoephedrine, as the availability of Nmethylmphetamine has remained high while prices have dropped and purity has increased.

…

While N-methylamphetamine itself is a powerful decongestant, it is less desirable in a medical setting because of its severe side effects and addictive properties. Such side effects may include insomnia, agitation, irritability, dry mouth, sweating, and heart palpitations. Other side effects
may include violent urges or, similarly, the urge to be successful in business or finance.

In our search for sources of N-methylamphetamine we have found that, similar to research grade chemicals purchased from the major chemical supply houses, the purity of the reagent varies greatly between suppliers and even between batches despite the above cited overall increase in purity. Unfortunately, and again similar to suppliers of fine chemicals, relative cost is not strongly correlated to sample quality.

I’ve used pseudoephedrine to treat nasal congestion the last few times I was sick. In Canada you can get pseudoephedrine mixed with acetaminophen (high doses cause liver failure) off the shelf, or straight-up by asking a pharmacist or ordering online. Phenylephrine is an alternative decongestant, although it is of dubious effectiveness.

In the States but not Canada, methamphetamine is available with a prescription under the brand name Desoxyn. It’s FDA approved for ADHD and obesity, and prescribed off-label for narcolepsy and depression. JFK was on methamphetamine along with a whole bunch of other powerful drugs for his big pile of medical conditions.