Sudafed (pseudoephedrine) typically starts working within 15 to 30 minutes after taking it. The effects of immediate-release (IR) Sudafed usually last about 4 to 6 hours. Extended-release (ER) versions take longer to start working (about 1 hour) but provide relief for 12 to 24 hours. For example, Sudafed Sinus Congestion 12 Hour tablets offer up to 12 hours of symptom relief, while Sudafed Sinus Congestion 24 Hour can last a full day
. In summary:
- Immediate-release Sudafed: effects begin in ~30 minutes, last 4–6 hours.
- Extended-release Sudafed: effects begin in ~1 hour, last 12–24 hours.
- The medication generally clears from the body within 1 to 4 days, depending on the product and individual factors
It is recommended not to use Sudafed for more than 7 days consecutively to avoid side effects and to consult a healthcare provider if symptoms persist
