The Netherlands Food and Consumer Product Safety Authority (NVWA) has issued a warning about five libido-enhancing products: LibiForMe, Mr Stiff (both liquid and capsule versions), Night Longer Mixed Herbal Blend, and Ayibogan Natural.

“Laboratory testing shows that these products contain sildenafil, tadalafil, and morphardenafil,” according to the NVWA. The substances pose serious health risks, the NVWA says. They may cause side effects such as chest pain, increased heart rate, headache, stomach problems, muscle pain, dizziness, and blurred vision. “In combination with certain medications for heart patients, these substances can lead to low blood pressure. Anyone who has used the product and experiences side effects should consult a doctor.”

The products are sold on multiple websites. The NVWA recommends not purchasing or using them.

The Netherlands Pharmacovigilance Centre Lareb reports having received a single notification about Mr. Stiff, involving symptoms such as eye pressure and changes in color vision.

The warning is particularly concerning because these types of products are often marketed as containing “natural, safe and effective ingredients”, despite laboratory tests showing the presence of pharmaceutical substances.

The harmful substances sildenafil and tadalafil were not listed on the label, meaning consumers may have unknowingly been exposed to pharmaceutical compounds in these products.

Sildenafil and tadalafil are prescription-only medicines in the Netherlands, available only through authorised medical use under a doctor’s supervision. Substances of this type are regulated by the Dutch Medicines Evaluation Board (CBG) and are not permitted as undeclared ingredients in food supplements.