If you say so I guess. All I know is that my dermatologist suggested I try an OTC of Claritin. When I went to the pharmacy, there were several Claritins on the shelf and one that had a tag that you had to take to the pharmacist to get the Claritin she had there. So I did that and she asked me for my drivers license. She said that the Claritin she was going to give me, while no prescrip. was needed, had to reported via her computer to the State Police.
I told her what I needed it for and she said the stuff that was on shelf would work just fine........
The homemade concoction that becomes Meth uses over the counter cold meds, allergy meds, etc. The hillbillies who make that stuff were going into Walmart, etc and buying tons of the otc meds. Once law enforcement started noticing the pattern, they decided to pull it off the shelves, or quantities of it so you had to show ID. It was an easy way to try to track who was buying large amounts in short periods of time. At least it was a cheap way to track, with mimimal inconvenience to the regular consumer - usually government involvement turns into a huge time and money waste.
It is NOT used as a precursor to meth production, either. It's just a very mild anti-histamine.