The Health Sciences Authority (HSA) has found that the weight loss product Ke Le sold online contains two potent undeclared medicinal ingredients that could pose serious health risks.

The ingredients, ephedrine and pseudoephedrine, are typically used as medicines to relieve blocked nose and cough. However, the seller's recommended daily dose would result in consumption of more than four times the limit of ephedrine used in the treatment of the common cold, flu and allergies.

The HSA warned yesterday that consuming such dangerously high levels of ephedrine can cause serious and life-threatening effects, especially for those with existing medical conditions, such as high blood pressure, heart problems and thyroid disease, or when the product is taken with others containing caffeine.

Adverse effects include increased heart rate, anxiety, insomnia, stroke, seizures and even death.

The HSA said Ke Le was promoted online as an appetite suppressant for weight loss. The seller, a Singaporean woman in her 30s, had posted testimonies and photos of herself before and after taking the product on a Facebook page named S.C.L.T.W.

She is now assisting the HSA in its investigations.

The HSA advises consumers of Ke Le to stop taking it immediately, and to consult a doctor if they feel unwell or are concerned about their health.