In most cases, you can buy Sudafed again .
This is not based on a calendar month (e.g., January 1st–31st). Instead, the system looks back at the previous 30 days from today. If those total purchases exceed 9 grams, you must wait until enough time has passed for an older purchase to "fall off" the 30-day window. How Much is 9 Grams? when can i buy sudafed again
To put these limits in perspective, 9 grams is roughly equivalent to of standard Sudafed. If you are using a 12-hour or 24-hour formulation, you may reach this limit faster than you expect. In most cases, you can buy Sudafed again
Legal Requirements for the Sale and Purchase of Drug ... - FDA In most cases