Pseudoephedrine
Medication
decongestant
cold & fluallergy
Not medical advice. Check with your doctor or pharmacist before you start, stop or change the timing of anything you take.
How to use
What it’s for
Blocked or stuffy nose from colds, sinusitis or allergies
When to take
Up to 4 times a day per NHS · not close to bedtime
Take with
With or without food · with a drink of water (NHS)
Pros & cons
Pros
- HealthHub: it is the part that clears a blocked nose
- SG: pharmacy-only — no prescription needed (HSA)
- Otc label: relieves cold, hay fever, sinus congestion
Cons
- Restlessness, trouble sleeping, dry mouth (NHS)
- NHS: a headache that persists — it can raise your bp
- SG: sold only inside combination products (HSA)
Sources
- HSA — Listing of Registered Therapeutic Products (open dataset on data.gov.sg, resource d_767279312753558cbf19d48344577084, pulled via datastore_search API; all 26 pseudoephedrine rows read, every one a combination product) · read 2026-08-27
what it says
“ZYRTEC-D · Pharmacy Only — TELFAST D TABLET · Pharmacy Only — CLARITYN-D 12HOUR REPETABS · Pharmacy Only — FEDAC TABLET · Pharmacy Only — PANADOL COLD RELIEF PSE CAPLET · Pharmacy Only — Aerius D-12 · Prescription Only”
- HSA — List of reclassified medicines (forensic classification definitions: POM / P / GSL) · read 2026-08-27
what it says
“Pharmacy-Only Medicine (P): A therapeutic product that can be obtained from a pharmacist at a retail pharmacy without a prescription … generally indicated for the short-term treatment of a minor condition or symptoms that can be readily identified”
- HealthHub (MOH Singapore) — Loratadine and Pseudoephedrine leaflet, pseudoephedrine text (article last reviewed 26 March 2026; no standalone pseudoephedrine page exists) · read 2026-08-27
what it says
“Pseudoephedrine helps to relieve blocked nose … You may take this medication with or without food … Trouble sleeping — Avoid taking too close to your sleep time … Restlessness … Dry mouth, skin and eyes … Headache”
- HealthHub (MOH Singapore) — Loratadine and Pseudoephedrine leaflet, precautions section (same page) · read 2026-08-27
what it says
“You have: High blood pressure … Heart disease or abnormal heart rhythm … Hyperthyroidism (overactive thyroid gland) … Diabetes … Glaucoma (high eye pressure) … Prostate or bladder problems … Liver or kidney problems”
- HealthHub (MOH Singapore) — Loratadine and Pseudoephedrine leaflet, interactions section (same page) · read 2026-08-27
what it says
“Do not take this medication with, or within 14 days of stopping, monoamine oxidase inhibitors (e.g. moclobemide and selegiline) … always check with your healthcare professional before taking two over-the-counter medications at the same time”
- NHS — How and when to take pseudoephedrine, 'Dosage and strength' (page last reviewed 2 November 2022) · read 2026-08-27
what it says
“Pseudoephedrine comes as 60mg tablets or as a liquid containing 30mg in 5ml. The usual dose is: adults and children aged 12 to 17 years – one 60mg tablet … up to 4 times a day”
- NHS — How and when to take pseudoephedrine, 'How to take it' and 'How long to take it for' (same page) · read 2026-08-27
what it says
“You can take pseudoephedrine tablets and liquid with or without food. Always take your tablets with a drink of water … You can take pseudoephedrine for a few days, usually up to 5 to 7 days”
- NHS — Side effects of pseudoephedrine (page last reviewed 2 November 2022) · read 2026-08-27
what it says
“A dry mouth … Feeling restless, nervous or shaky … Difficulty sleeping … If your headache does not go away, or gets worse, stop taking pseudoephedrine and contact 111. It may be because pseudoephedrine can increase your blood pressure”
- NHS — Taking pseudoephedrine with other medicines and herbal supplements (page last reviewed 2 November 2022) · read 2026-08-27
what it says
“Check with a pharmacist or doctor if you're taking: antidepressants known as monoamine oxidase inhibitors (MAOIs) … digoxin … tricyclic antidepressants, such as amitriptyline … ergot alkaloids … medicines for high blood pressure, such as beta blockers or methyldopa”
- NHS — Taking pseudoephedrine with other medicines, decongestant warning (same page) · read 2026-08-27
what it says
“Do not use pseudoephedrine at the same time as other medicines for a blocked nose, such as xylometazoline and oxymetazoline. This includes nasal sprays or other tablets and capsules for congestion”
- DailyMed / FDA — SUDOGEST (pseudoephedrine HCl 30 mg) tablet, OTC Drug Facts 'Uses' (Major Pharmaceuticals; label updated 12 May 2026) · read 2026-08-27
what it says
“temporarily relieves nasal congestion due to the common cold, hay fever or other upper respiratory allergies … temporarily relieves sinus congestion and pressure … Nasal decongestant”
- DailyMed / FDA — SUDOGEST, OTC Drug Facts 'Directions' (same label) · read 2026-08-27
what it says
“Pseudoephedrine HCl 30 mg … Directions: take every 4-6 hours … do not take more than 4 doses in 24 hours … adults & children 12 years & over 2 tablets”
- DailyMed / FDA — SUDOGEST, OTC Drug Facts 'Do not use' warning (same label) · read 2026-08-27
what it says
“Do not use if you are now taking a prescription monoamine oxidase inhibitor (MAOI) … or for 2 weeks after stopping the MAOI drug”
- DailyMed / FDA — SUDOGEST, OTC Drug Facts 'Ask a doctor' and 'Stop use' warnings (same label) · read 2026-08-27
what it says
“Ask a doctor before use if you have heart disease, high blood pressure, thyroid disease, diabetes, trouble urinating due to an enlarged prostate gland … Stop use and ask a doctor if nervousness, dizziness, or sleeplessness occur”
Updated 2026-08-29. Every line above traces to a numbered source. Kozen-X is not a medical device and does not give medical advice. It lists what published sources have written down — nothing more. A pair not listed is unrecorded, not cleared. Before you start, stop or re-time anything, talk to your doctor or pharmacist.