Ergogenic effects of pseudoephedrine on edurance performance in relation to the determination of threshold values in urine and capillary and venous blood
Pseudoephedrine is an ingredient commonly found in over-the-counter cold and flu remedies to relieve blocked noses. Because it is a mild stimulant, sports authorities closely monitor its use to prevent unfair advantages. This study aims to find out whether taking standard or higher doses of pseudoephedrine actually improves endurance cycling performance. Researchers will invite healthy adult volunteers to complete a simulated 90-minute cycling race. Participants will take either a dummy pill (placebo) or one of two doses of pseudoephedrine on different test days. The research team will track cycling speed, power, heart function, and body metabolism. They will also test different ways of taking blood and urine samples to see how the body clears the medicine. The findings will help doctors and sports anti-doping organisations better understand safe and fair threshold levels.
At a glance
What is this study about?
Many people have taken pseudoephedrine at some point to clear a stuffy nose during a cold. It works by narrowing the blood vessels in your nasal passages. However, because it can also slightly raise heart rate and alertness, there has long been a debate in sports medicine about whether it gives athletes an unfair physical edge in endurance events.
This clinical study is designed to answer that question clearly and safely. Researchers want to see if taking pseudoephedrine changes how fast or hard a person can cycle during an intense 90-minute exercise session. They will compare a normal dose (120 mg) and a higher dose (240 mg) against a dummy pill (a placebo) that contains no active medicine at all.
In addition to measuring cycling times and power output, the study team will monitor how the heart, lungs, and muscles handle the exercise. They will also collect blood and urine samples using various modern testing methods, including simple finger-prick tests, to see how long the drug remains detectable in the body.
Ultimately, this research will provide clearer guidance for sports regulators and doctors. It will help ensure that anti-doping rules are grounded in solid scientific evidence, protecting both fair competition and athlete safety.
Key takeaways
- The trial tests whether the decongestant pseudoephedrine improves endurance cycling performance.
- Healthy volunteers aged 18 and over will cycle for 90 minutes after taking different doses or a dummy pill.
- Researchers will track power output, heart function, and drug levels in blood and urine.
- The results will help sports authorities set fair and accurate anti-doping testing limits.
- Participation is voluntary, and you can stop taking part at any time.
Who may be eligible?
This trial is open to healthy men and women aged 18 and older. Because the study involves a demanding 90-minute cycling test, participants should generally be in good health and physically capable of intense aerobic exercise.
People with certain pre-existing health conditions—particularly high blood pressure, heart rhythm problems, or other cardiovascular issues—will not be able to join. This is because pseudoephedrine can raise blood pressure and make the heart beat faster, which could be unsafe during hard exercise.
If you take regular prescription medicines or have allergies to decongestants, the study team will carefully check whether it is safe for you to take part.
Could this study suit you?
Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.
- I am aged 18 or older.
- I consider myself to be in good general health.
- I am comfortable doing intense cycling exercise for up to 90 minutes.
- I do not have high blood pressure, heart conditions, or serious medical illnesses.
- I am not allergic to pseudoephedrine or similar cold medicines.
What does participation involve?
Taking part in this study involves several visits to a sports testing laboratory. You will complete simulated cycling time trials lasting about 90 minutes each, spaced out over several days or weeks to allow your body to recover.
Before each cycling session, you will be given a tablet to take. In some sessions, this will be pseudoephedrine (at either a 120 mg or 240 mg dose), and in another, it will be an inactive dummy pill (placebo). Neither you nor the researchers testing you will know which pill you are taking on which day until the study is finished.
During and after the cycling tests, the team will monitor your heart rate, breathing, and energy use. They will also take regular urine samples and small blood samples, using standard arm blood draws as well as gentle finger-prick techniques. Your health will be monitored closely throughout each visit.
Potential risks and benefits
Locations (1)
- —UnverifiedBelgium
Common questions
What is pseudoephedrine?
Pseudoephedrine is a common medicine used in over-the-counter cold and flu tablets to help unblock a stuffy nose.
Is pseudoephedrine banned in sport?
Yes, above certain levels. Anti-doping organisations set strict limits on how much pseudoephedrine can be in an athlete's system during competition.
Will taking this medicine make me fitter?
No. The medicine may only cause temporary changes in alertness or heart rate during the test; it does not build lasting fitness or muscle.
What is a placebo?
A placebo is a dummy pill that looks just like the real medicine but contains no active ingredients. It helps scientists see if effects are genuinely caused by the drug.
Can I leave the study if I feel unwell?
Yes. Taking part is completely voluntary. You can stop cycling or withdraw from the trial at any time if you feel uncomfortable.
How to find out more
Always speak to your GP or specialist before deciding to take part in a study.
Interested in taking part?
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