SINGAPORE -- Singapore's health products regulator said Friday it had alerted its counterparts in China, Hong Kong and Southeast Asia about an illegal sexual enhancement pill as 10 men were taken to hospital after taking the drug.

The Health and Sciences Authority (HSA) said the men, aged 30-70, fell ill after taking the Power 1 Walnut, which was found to contain high amounts of controlled drugs.

Tests found it had glibenclamide, a prescription drug for diabetes, and sildenafil -- sold as Viagra -- which is used to treat erectile dysfunction.

Another 29 people are thought to have been affected after taking the drug but this could not be confirmed, HSA said.

The victims developed symptoms of low blood sugar levels, which include dizziness, cold sweats, anxiety and loss of consciousness.

An analysis showed it contained an over-concentration of glibenclamide, which could lead to seizures, unconsciousness, stroke and even death, the regulator said.

"HSA has alerted its counterparts in the ASEAN (Association of Southeast Asian Nations) region as well as China and Hong Kong to keep a lookout on this particular product adulterated with glibenclamide and sildenafil," it said.

More than 75,000 Power 1 Walnut and other illegal sexual potency drugs with a street value of 200,000 Singapore dollars (143,000 US dollars) have been seized and four people are being investigated, the HSA said.

It said the drug is labelled as being manufactured by a firm called Guangzhou Xinkauili Limited Company and is likely to have been illegally brought into Singapore. It claims to contain only natural herbal ingredients.