Sudafed (Pseudoephedrine) at a glance: schedule, half-life, and class
- Generic name
- Pseudoephedrine hydrochloride or sulfate
- Brand names
- Sudafed; in Claritin-D, Allegra-D, Zyrtec-D, Advil Cold and Sinus
- Drug class
- Sympathomimetic decongestant
- US legal status
- Over the counter behind the counter; List I chemical
- Purchase limits
- 3.6 g a day and 9 g in 30 days, with photo ID and a logbook
- Forms
- Tablets, extended-release tablets, liquid
- Onset
- About 30 minutes
- Half-life
- About 5 to 8 hours
Sudafed uses: what pseudoephedrine is prescribed for
Pseudoephedrine shrinks swollen blood vessels in the nose and sinuses, relieving congestion from colds, allergies, and sinus infections.[1]
The oral decongestant phenylephrine, sold on regular shelves, does not work by mouth. An FDA panel concluded this in 2023, and in 2024 the FDA proposed removing oral phenylephrine from the market, leaving pseudoephedrine as the effective oral option.[2]
How much pseudoephedrine is safe to take?
These directions come from the over-the-counter Drug Facts label.[1]
| Product or group | Label directions | Notes |
|---|---|---|
| Immediate release, adults and children 12 and over | 60 mg every 4 to 6 hours | No more than 240 mg in 24 hours |
| 12-hour extended release | 120 mg every 12 hours | Maximum 240 mg a day |
| 24-hour extended release | 240 mg once a day | Swallow whole |
| Children under 12 | Follow the product label | Not recommended under 4 |
Sudafed (pseudoephedrine) side effects and risks
Common side effects include restlessness, insomnia, fast heartbeat, and nervousness.[1]
Blood pressure and heart: it can raise blood pressure; people with uncontrolled high blood pressure or heart disease should ask a clinician first.[1]
Rare brain effects: European regulators reviewed rare cases of posterior reversible encephalopathy syndrome and reversible cerebral vasoconstriction syndrome in 2023 and added warnings.
Urinary retention in men with enlarged prostates.
Sudafed interactions: what not to mix with pseudoephedrine
Choose what it would be combined with:
| Combined with | What happens | Guidance |
|---|---|---|
| MAO inhibitors (within 14 days) | Hypertensive crisis | Contraindicated |
| Other stimulants and decongestants | Overstimulation, high blood pressure | Avoid doubling |
| Blood pressure medicines | Reduced effect | Ask a pharmacist |
| Caffeine | More jitteriness and insomnia | Limit |
This is not a full list. A pharmacist can check a complete medication list, including supplements and over-the-counter products.[1]
Sudafed overdose: signs of pseudoephedrine overdose and what to do
Overdose causes agitation, tremor, very high blood pressure, fast or irregular heartbeat, hallucinations, and seizures.[1]
If someone may be overdosing
- Call 911 for chest pain, a seizure, trouble breathing, signs of a stroke (face drooping, weakness on one side, slurred speech), a very high body temperature, or if the person collapses.
- Move them somewhere cool and calm, loosen tight clothing, and cool the skin with water. Do not try to hold them down.
- If they become unresponsive or their breathing slows, give naloxone. Street stimulants are often contaminated with fentanyl.
- For advice when the person is awake and stable, call Poison Help at 1-800-222-1222.
Is Sudafed (pseudoephedrine) addictive?
Pseudoephedrine has low misuse potential at label doses and does not cause significant withdrawal. Its main regulation is to stop it being diverted to make methamphetamine.[3]
- After stoppingNo withdrawalCongestion may return.
- Rebound congestionNot typicalUnlike nasal decongestant sprays, oral pseudoephedrine does not usually cause rebound.
- Ongoing congestionSee a clinicianNasal steroid sprays treat allergic congestion.
How do you buy pseudoephedrine safely in the US?
Pseudoephedrine is sold without a prescription, but under the Combat Methamphetamine Epidemic Act of 2005 it must be kept behind the counter or in a locked case.[3]
- ID and logbook: buyers must show photo ID and sign a logbook, usually electronic and shared across pharmacies.
- Limits: no more than 3.6 grams of pseudoephedrine a day and 9 grams in 30 days, regardless of the number of stores.
- State rules: some states set lower limits; Oregon required a prescription from 2006 until 2022.
- Cost: generic pseudoephedrine is inexpensive.
- Ask a pharmacist: a pharmacist can check whether it is safe with your other medicines and health conditions.
Can you buy pseudoephedrine online?
Only in limited ways. Because of federal purchase limits and logbook rules, online sales of pseudoephedrine are restricted. Most people buy it from the pharmacy counter with ID.
The FDA's BeSafeRx tool explains how to recognize a safe online pharmacy.[4]
Is Sudafed legal? Pseudoephedrine legal status in other countries
| Country | Status |
|---|---|
| United Kingdom | Pharmacy medicine with pack-size limits |
| Australia | Pharmacist-only medicine with real-time sales recording |
| Mexico | Banned since 2008 |
| International | Listed precursor chemical (Table I of the 1988 UN Convention) |
Laws change and differ in detail. Check current rules before carrying any controlled medicine across a border.[5]
Common questions about Sudafed (pseudoephedrine)
Why is Sudafed behind the counter?
Because pseudoephedrine can be used to make methamphetamine, federal law requires ID, a logbook, and purchase limits.
Is Sudafed PE the same as Sudafed?
No. Sudafed PE contains phenylephrine, which does not work as a decongestant when taken by mouth.
Can Sudafed (pseudoephedrine) raise blood pressure?
Yes. People with high blood pressure should check with a clinician first.
How much Sudafed (pseudoephedrine) can I buy?
Up to 3.6 grams a day and 9 grams every 30 days under federal law.
Can Sudafed (pseudoephedrine) keep you awake?
Yes. Insomnia is common, so avoid late doses.
Sources
- Sudafed (pseudoephedrine) prescription information. DailyMed, US National Library of Medicine.
- FDA proposes ending use of oral phenylephrine as OTC monograph nasal decongestant active ingredient after extensive review. US Food and Drug Administration, November 2024.
- 21 CFR Part 1314, Retail sale of scheduled listed chemical products. Electronic Code of Federal Regulations.
- BeSafeRx: Your Source for Online Pharmacy Information. US Food and Drug Administration.
- International drug control conventions. United Nations Office on Drugs and Crime.
