The National Precursor Log Exchange Program (NPLEx) officially kicked off this month in West Virginia . It tracks the number of times you buy over-the-counter cold medicine containing pseudophedrine.
Meant to catch meth-making criminals before they leave the pharmacy, it loads that information into an online database that is instantly accessible to police.
Lawmakers set the purchase limits at 7.6 grams per month. It varies by brand, but that equals about two packages of the popular drug Claritin D.
Officials say that allows you to take the maximum daily dosage every day to fight colds or allergies.
If you go over that limit, officials say you'll be flagged in the system and pharmacists will deny the sale.
Officials say if you need to buy more than the limit allows, you'll have to get a prescription from your doctor.
Officials say the system also works in Ohio , Virginia and Kentucky to catch criminals who try to cross state borders.