SINGAPORE - The Health Sciences Authority (HSA) has issued an alert on two illegal health products containing potent ingredients that could cause heart attacks, vomiting, and stomach ulcers.

One product, called Li Da DaiDaiHua Weight Loss Capsule, contained sibutramine, which has been banned since 2010. Members of the public alerted the HSA to the drug, which was being sold online, HSA said in a statement.

The other, called Du Zhong Jin Gu Wan, was purchased by a woman in her 70s for joint pain. The woman then visited a traditional Chinese medicine doctor, who became alarmed after she reported immediate pain relief following use of the drug.

It was found to contain several potent ingredients, including a steroid which should only be used under strict medical supervision.

The HSA said in a statement that it had not yet received reports of people suffering adverse effects from using these products.

However, it added that this did not mean the products are safe.

"As illegal health products are generally produced under poor manufacturing conditions with no quality control and the contents of the products can vary from batch to batch, they can pose serious health hazards," it stated.