Why Do Decongestants Cause Insomnia?

Many of these decongestants contain pseudoephedrine-like substances, which can make your heart race, increase blood pressure, and make you feel jittery (also a factor in insomnia!)

Do decongestants keep you awake?

Decongestants may keep you awake and are usually taken during the day. Nasal sprays are less likely to have that side effect and may be helpful at night for congestion. Decongestants can also raise blood pressure. So if your BP is high already, or you've got heart disease, check with your doctor before you use them.

Does pseudoephedrine cause insomnia?

SIDE EFFECTS: Nausea, vomiting, trouble sleeping, dizziness, headache, or nervousness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Stop taking this medication and tell your doctor promptly if you have dizziness, nervousness, or trouble sleeping.