Many chemicals have "isomers"
Methamphetamine is one of them
In this chemical there is a d- isomer, and l- isomer, basically 2 chemicals that are the exact same, but are mirror images of each other (example: your hands)
racemic methamphetamine is 50% d-methamphetamine 50% l-methamphetamine
d-meth is the extremely potent dopamine releasing agent
l-meth has negligible dopamine release, but it is a norepinephrine releasing agent
Conclusion: There is no recreational value from consuming the l-meth in Vick's inhalers
Fun Fact: Meth made from pseudoephedrine (the most popular method) only produces d-methamphetamine, no l-methamphetamine is created
That being said, almost all meth on the USA's streets is d-meth, with no l-meth