It was touted as a "herbal health" product intended to improve a man's vigour. But the Health Sciences Authority (HSA) found that it contained undeclared medicinal ingredients used to treat erectile dysfunction, which should not be taken without medical supervision.

"In the case of patients with heart conditions, these products can interact with the patients' medications such as nitrates and can cause death," said the authority of the Herbal Health V+ product on Tuesday.

Herbal Health V+ was among six products flagged by the HSA. The other five, marketed under the Herbal Health brand by Ace Nutrition International, include Backplus 500mg, RU Special Cream, YI Special Cream, JI Special Cream and Xiang Special Cream. The HSA has since seized the products from the company's premises in Kallang Pudding Road and stopped all sales of these products.

"HSA is currently investigating the source of manufacturing of these products," said a spokesman. Members of the public who have any information on the sale of the Herbal Health products or other illegal products may contact HSA Enforcement Branch on 6866-3485 or e-mail hsa_is@hsa.gov.sg.

The Herbal Health range of creams claimed to treat skin conditions such as itchiness, eczema, dry skin, scaling heels and fungal infections but active ingredients are not listed on their labels.

Tests by HSA, however, revealed that they contained undeclared "Western medicinal ingredients which included an anti-allergy ingredient".

"Beware of miracle cures, even if friends recommend them... Do not buy dodgy products from small shops or off the street," said Dr Philip Koh of Healthway Medical Group.

HSA advises those taking the products to stop consumption immediately and seek medical advice.