It comes full circle if you go back far enough.

Before Sudafed was common in pills, they had the small disposable inhalers where the pseudoephedrine was not in crystal form but was dissolved in vaporous liquids like menthol. Inside the inhaler there is a cotton piece soaked with the pleasant-smelling liquid. The aroma vapors are drawn right up into the sinuses along with the active ingredient.

The inhaler itself was first marketed during World War II by the well-established 19th century Vicks company, already very successful for decades with it's earlier VapoRub aromatic topical OTC formulations. People are probably aware that this is one of the companies that is older than the US FDA. Older than the Fed & income taxes too, for those who are keeping score ;)

Natural products like ephedrine have long been the inspiration for medicinal chemists to synthesize similar compounds for potential screening as new drugs, so a number of new experimental relatives such as pseudoephedrine were produced eventually.

As the name implies, people did not always know what the real difference was between ephedrine and pseudoephedrine, since both molecules have the same molecular weight, naturally because both have the same number of carbons, hydrogens, oxygen, and nitrogen content.

Only a slight difference in chemical structure between the two, which got figured out soon enough.

Some of the less-similar new drug candidates were ordinary amphetamines. They are the ones that really got popular fast, especially in wartime :\

Now when the unique inhalers were born, it was a bit of the new synthetic ingredient along with the traditional aromatic mixture that Vicks was famous for, and the Vicks Inhaler was deemed safe & effective as recommended for OTC use. People loved it. Nobody had ever had anything as effective as that.

IIRC it was 50 milligrams per inhaler soaked into a few hundred milligrams of aromatic essential oil mixture. As expected they were a lot stronger when you first started smelling one.

That's because it was 50 mg of meth-amphetamine in the Vicks inhalers.

Parents would buy them for their kids, because they were so "safe", for self medication naturally, even at times when they would not consider dosing them up with cough syrup.

There was never any FDA-approved prescription for methamphetamine in any other form, only this one OTC product.

I would think the inhalers themselves were patent encumbered until the 1960's (remind you of an Epipen?) and by the 1970's other companies like Sudafed offered their own version, only not containing meth, give me a break.

The meth version of amphetamine became recognized as a dangerous drug in the after-war years when the negative effects became apparent with soldiers who had been given it in pill form habitually as stimulants, often when facing the most serious combat.

No other company ever was able to put meth in their inhalers, but Vicks slipped in under the wire and couldn't even be stopped for decades until some time after the DEA came into being. Everybody else was using pseudoephedrine from the start. By this time crystal meth was just beginning to emerge, which people were trying to avoid when they saw what it was like, at the same time different people started seeking meth more intently. Orders of magnitude more out-of-hand now.

The way Vicks stayed under the radar the whole time with meth in it, was hiding in plain sight.

Right there on the inhaler in fine print where it always was, active ingredient desoxyephedrine 50 mg.

Simply a less-common alternative chemical name for meth, and desoxyephedrine had become a very uncommon rapidly deprecated name quite early. Way before any amphetamines were commercialized, they were instead marketed using the well-known convention based on the Alpha-MethylPHenylEThylAMINE type nomenclature.

Anyway, back in the 1970's when it was first becoming known that shady operators were cooking meth by starting with inhalers, I looked at one of them and sure enough, 50 mg meth per Vicks inhaler. Who knew?

For a while there I figured they must be starting with way over 20 inhalers and probably would not extract nearly a gram of meth but it sounded feasible. I wasn't going to be the one to do it, my first job out of college was working for a company that was a real pharmaceutical manufacturer. So I wasn't going to tell anybody either. There was already talk among law enforcement about cracking down on this kind of thing. Suspicion of inhalers was beginning to barely arise, it was thin but widespread among anybody who had heard anything about this.

Eventually I figured out that the clandestine cookers were synthesizing their meth by using the pseudoephedrine in non-Vicks inhalers as starting material for their reactions ! Well, what do you know? Was I wrong the whole time?

I "guessed" so.

With not-so-blurry 20/20 hindsight, I would estimate that before I got around to figuring this out, a clandestine chemist had come along way before I knew a thing and had started out extracting grams of meth directly from Vicks inhalers. And the meth heads loved it, found out it was coming from inhalers and the word got around among them.

Some other chemist picks up the inexact word-of-mouth and by this time Vicks inhalers are outnumbered, sharing shelf space with numerous alternative brands, all of them containing pseudoephedrine as expected, and cheaper too. If they look at Vicks, it's the odd ball out, that doesn't look like the same kind of "ephedrine" as everything else. So they figured out how to do some home made reactions starting with Sudafed. And this is what was just starting to go through the roof.

This was before the Sudafed pills really took over, once they showed up they flew off the shelf way faster than the inhalers because there were more milligrams.

One day in the '70's I was in Walgreens and there was somebody buying over a dozen Sudafed inhalers so I knew what they were up to.

I went over to the aisle and looked at the then-current Vicks Inhaler, which I hadn't checked in a while, sure enough 50 mg of desoxyephedrine, active ingredient, same as ever.

The poor Sudafed buyer wasn't the least bit aware that real meth was right there on the shelf next to it.

And I wasn't going to say a thing :)

Most doctors and pharmacists didn't even have a clue.

Within a few years Vicks stated putting in pseudoephedrine themselves instead of meth.

Until it got way too far out of hand and the pseudoephedrine became tightly controlled, much more tightly than the meth was, as can be seen.

Edit:

"And now you know the rest of the story" - Paul Harvey