Comment by kens

Chances are that you bought the useless Sudafed PE. The (original) Sudafed is pseudoephedrine. Sudafed PE is phenylephrine. The molecules are similar, but the latter cannot be easily converted to methamphetamine so it is not regulated like the former. Sudafed is an effective nasal decongestant, while Sudafed PE is equivalent to a placebo. [1]

[1] https://pubmed.ncbi.nlm.nih.gov/19230461/