Standard Sudafed Dosing for Adults

The dose of Sudafed you should take depends on which strength tablet you have. Pseudoephedrine — the active ingredient in Sudafed — comes in 30 mg and 60 mg tablets. For the 30 mg tablet, take one tablet every 4 to 6 hours, up to four times daily. For the 60 mg tablet, take one tablet every 12 hours, up to twice daily. Do not exceed 240 mg in 24 hours.

The 60 mg extended-release tablets are designed to work longer, so you take fewer doses. The 30 mg regular tablets work faster but wear off sooner, which is why you can take them more often. Check your package label — it will say either "30 mg" or "60 mg" clearly on the front.

Take each dose with a full glass of water. You can take Sudafed with or without food. If you forget a dose, skip it and take your next dose at the regular time — never double up to make up for a missed dose.

Key Takeaways

  • The 30 mg tablet is taken one tablet every 4 to 6 hours, up to four times per day, with a maximum of 240 mg in 24 hours.
  • The 60 mg tablet is taken one tablet every 12 hours, up to twice per day, with the same 240 mg daily maximum.
  • Children under 12 years old should not take Sudafed unless a doctor directs it; children 12 and older follow adult dosing.
  • Do not take Sudafed for more than 7 days in a row without talking to a doctor, as prolonged use can cause rebound congestion.
  • Certain blood pressure medications and heart conditions mean you should not take Sudafed at all — check with a pharmacist or doctor first.

Dosing for Children and Teens

Children under 12 years old should not take regular Sudafed tablets. The FDA does not recommend pseudoephedrine for young children because the risks outweigh the benefits. If your child has nasal congestion, talk to a pediatrician about safer alternatives like saline rinse or a humidifier.

Children 12 years old and older can take the adult dose — one 30 mg tablet every 4 to 6 hours (up to four times daily) or one 60 mg tablet every 12 hours (up to twice daily). The 240 mg daily maximum applies to teens as well.

When Not to Take Sudafed

Do not take Sudafed if you have high blood pressure, heart disease, thyroid problems, diabetes, or glaucoma without first checking with a doctor or pharmacist. Pseudoephedrine can raise blood pressure and heart rate, which is dangerous for people with these conditions.

Also avoid Sudafed if you are taking certain medications, including some antidepressants (especially MAOIs), some blood pressure drugs, or stimulant medications. The combination can cause serious interactions. If you take any prescription or over-the-counter medications regularly, show the pharmacist your Sudafed box before you buy it.

Pregnant women should talk to their doctor before taking Sudafed. Some doctors say it is safe in the second and third trimester, but others prefer other options. Do not assume it is safe just because it is over-the-counter.

Common Mistakes and Side Effects

The most common mistake is taking Sudafed for more than 7 days in a row. After a week, your nasal passages can become dependent on the medication, and congestion actually gets worse when you stop — this is called rebound congestion. If you need relief for longer than a week, see a doctor instead of continuing to take Sudafed.

Another mistake is mixing Sudafed with other cold medicines that also contain pseudoephedrine. Check the label of any other cold or allergy medication you are taking — many combination products include pseudoephedrine, and taking two at once can push you over the safe daily limit.

Common side effects include jitteriness, insomnia, headache, and a racing heartbeat. These are usually mild and go away as the dose wears off. If you feel chest pain, severe headache, or difficulty breathing, stop taking Sudafed and call a doctor or poison control when ready.

How Long Sudafed Takes to Work

Regular 30 mg Sudafed tablets start working within 30 minutes and reach peak effect in about 1 to 2 hours. The effect lasts 4 to 6 hours, which is why you can take another dose after that window.

Extended-release 60 mg tablets take a bit longer to start — usually 45 minutes to 1 hour — but they work for 12 hours. If you need faster relief, the 30 mg tablet is the better choice. If you want to take fewer doses throughout the day, the 60 mg tablet is more convenient.

Storage and Expiration

Store Sudafed at room temperature, away from heat and moisture. Keep it in its original container with the label intact so you can always see the strength and instructions. Do not store it in the bathroom medicine cabinet, where humidity from the shower can degrade it.

Check the expiration date on the box before you take a dose. Expired Sudafed may not work as well and could be unsafe. If your Sudafed is expired, throw it away and get a new box.

Frequently Asked Questions

Can I take Sudafed with other pain relievers like ibuprofen or acetaminophen?

Yes, Sudafed can be taken with ibuprofen or acetaminophen. Many people take them together for cold symptoms — Sudafed for congestion and ibuprofen or acetaminophen for aches and fever. Just make sure you do not exceed the daily maximum for either drug, and space out your doses if you are taking multiple medications.

What if I accidentally took more than the recommended dose?

If you took one or two extra tablets, monitor yourself for dizziness, rapid heartbeat, or trembling. Drink water and rest. If you took a much larger amount or feel seriously unwell, call Poison Control at 1-800-222-1222 (available 24/7 in the US) or go to an emergency room. Have the Sudafed box with you so you can tell them the strength.

Is Sudafed safe to take every day during cold season?

No. Sudafed is meant for short-term relief — up to 7 days at a time. Taking it daily for weeks or months can lead to rebound congestion and other problems. If you have chronic nasal congestion, talk to a doctor about longer-term solutions like nasal steroid sprays or allergy testing.

Why is Sudafed kept behind the pharmacy counter?

Pseudoephedrine can be used to manufacture illegal drugs, so the FDA requires it to be kept behind the counter and limits how much one person can buy per month. You do not need a prescription, but you will need to show ID and sign a log when you purchase it.

Does Sudafed make you drowsy?

No. Sudafed is a decongestant and typically causes the opposite effect — it can make you feel jittery or keep you awake, especially if taken in the evening. If you need a decongestant that also helps you sleep, look for products that combine pseudoephedrine with an antihistamine like diphenhydramine, which does cause drowsiness.