A small plastic bottle, a pump that slightly creaks when used, and a minty smell instantly recognizable — this decongestant spray has been a go-to remedy for stuffy noses for generations. Found in nearly every French bathroom, it’s often kept alongside bandages and thermometers, ready for use at the first sign of a cold. However, this seemingly routine action has recently caught the attention of health authorities. Behind this automatic gesture lies a mechanism that many households are not fully aware of — one that could challenge long-held habits. Prolonged use of decongestant sprays containing vasoconstrictors, such as pseudoephedrine, can lead to a rebound effect, making nasal congestion worse over time. The French National Agency for the Safety of Medicines and Health Products (ANSM) has confirmed that these products can cause rare but serious cardiovascular and neurological side effects. As a result, the agency has required a prescription for all medications containing pseudoephedrine, including oral forms, since the end of 2024. For colds that typically resolve on their own within one to two weeks, the ANSM recommends gentler alternatives such as nasal irrigation with salt water, steam inhalation, or simply resting. The use of decongestant sprays has become so ingrained in daily life that it is often performed without much thought. This reflex, passed down through generations, has become a family norm. For many years, these vasoconstrictor-based products, including the well-known pseudoephedrine, were seen as safe and effective, largely due to advertising that promised quick relief. As a result, few people read the accompanying leaflets or adhere to the recommended duration of use. This commercial success, however, has masked a more complex reality: while these drugs offer short-term relief, they can be risky if used without caution. The real issue lies in the rebound effect — a phenomenon where the nasal congestion returns, and even worsens, after stopping the use of the spray. The nasal blood vessels, continuously stimulated by the medication, eventually dilate when the treatment stops, leading to more persistent blockage. This creates a vicious cycle, pushing people to use the product again and again. Beyond this, the ANSM has reported more serious side effects, such as cardiovascular issues and neurological conditions like posterior reversible encephalopathy syndrome, which can affect individuals with no prior medical history. Given that colds typically last only a week or two, these risks seem disproportionate for such a mild illness. In response to these findings, the ANSM has strengthened regulations around these medications. Since late 2024, all oral medications containing pseudoephedrine require a prescription, a rule that also now applies to nasal forms, which had previously required a prescription due to their potential side effects. Earlier restrictions on mass advertising were not enough to curb misuse, as many people ignored treatment guidelines without medical advice. Recent studies confirm that less than 15% of over-the-counter decongestants are both effective and safe in the long term. Now, a medical consultation is required before using these products, and gentler options like salt water nasal irrigation, steam, and rest are being encouraged as first-line responses to a stuffy nose. This small, familiar bottle, once seen as a simple solution, now reveals a more complex reality — one that demands caution and awareness. As seasonal colds begin to appear, it may be time to rethink this inherited reflex and consider patience over quick fixes.