The Health Sciences Authority (HSA) has issued an alert on an illegal health product from China.
Labelled "Huo Luo Jing Dan", it was found to contain potent corticosteroids, dexamethasone and prednisolone.
Prolonged use of these corticosteroids can cause harmful effects like weak bones and a depressed immune system.
Besides the corticosteroids, the pills also contained indomethacin, a non-steroidal anti-inflammatory drug, which can cause stomach bleeding and kidney failures.
A local doctor first alerted the HSA to the product when he suspected that his patient was suffering from its adverse effects.
The female patient, 50, had developed a swelling of the throat following an infection that did not heal and was hospitalised. She had also developed a moon face - where the face swells up to a rounded shape - cause by the prolonged intake of corticosteroids.
She had reportedly been taking the pills for years and had bought it from a friend who could not been contacted.
She has since recovered and is discharged from the hospital after discontinuing product intake.
Investigations by HSA showed that the product manufacturer - China Tian Jin Ren Ji - as printed on the bottle's label does not exist.
HSA strongly urges members of the public not to consume the product. Those who are aware of the product being sold illegally, to provide information to assist investigation by contacting HSA's Enforcement Branch at 6866 3485 (24-hour line) or e-mail: hsa_is@hsa.gov.sg.