Consumers are advised not to purchase or consume the product, the agency said, adding that those who have consumed it and have concerns about their health should seek medical advice.
Checks by reporters found that the product was previously listed for sale on Shopee and Lazada, but those listings have since been taken down.
Tadalafil is a prescription medicine used to treat erectile dysfunction and should only be given under medical supervision, the agency said.
Inappropriate use of tadalafil is dangerous and can increase the risk of serious adverse effects, including heart attack, stroke, headache, migraine, irregular heart rate as well as priapism, also known as painful and prolonged erections.
It can also pose serious risks to certain individuals, including those with heart-related problems.
The medication may cause potentially life-threatening low blood pressure in those who are on heart medications, especially those containing nitrates, the agency added.
Singapore orders recall of baby food for containing too much arsenic
Singapore orders recall of baby food for containing too much arsenic
The agency advised consumers to be cautious and mindful of the risks associated with consuming food bought from unknown or unverified sources. They are also advised to seek more information before purchasing the products.
The agency added that it will not hesitate to take stern enforcement action against those who sell and supply food products that are found to be adulterated with banned substances or potent ingredients.
Those found guilty face a fine not exceeding S$5,000 (US$3,700). If there is a second or subsequent conviction, a person may be fined up to S$10,000, jailed for up to three months, or both.