SINGAPORE - Four products sold on e-commerce sites and social media platforms have been found to contain banned substances or laxatives.

Three of the products - Nutriline Thinsline, KiMiSo Dark Chocolate, and Wholly Fitz Passion Lemon Tea contain sibutramine, a banned substance that could increase the risk of heart attack and stroke.

The fourth, Nutriline Cleansline, contains the laxative sennoside, said the Health Sciences Authority (HSA) on Thursday (Sept 10).

The public should not purchase or consume these products said the HSA, adding that all sellers and suppliers must stop selling these products immediately as well.

The HSA said a woman had reported that she experienced extreme thirst, irregular heartbeat and loss of appetite after taking one sachet of Nutriline Thinsline.

Investigations by the authority found that the product was usually sold together with Nutriline Cleansline.

Both products had been marketed as natural supplements for weight loss and detoxification with claims to control appetite and increase metabolism of users.

A different woman alerted the HSA to KiMiSo Dark Chocolate. She suspected the product contained potent ingredients after reading reviews.

The product claimed to promote weight loss with no laxatives and no side effects.

HSA tested it and detected sibutramine and diphenhydramine, an antihistamine which causes drowsiness and can pose a risk in consumers who drive or operate machinery.

The products were sold on local e-commerce platforms such as Shopee and Qoo10, and social media platforms such as Facebook and Instagram.

The HSA has issued warnings to the sellers of these four products.

The authority has also directed the respective website administrators to remove the affected listings.

Consumers are advised to stop taking these products immediately and to consult a doctor if they are feeling unwell or are concerned about their health.

The HSA said the public should be wary of health products that carry exaggerated claims or deliver unexpectedly quick results.

"There is no quick and easy way to lose weight. Weight control should be achieved through a combination of balanced diet and appropriate exercise," added the authority.

Sellers and suppliers of products with banned and harmful ingredients will be prosecuted. If convicted, they may be jailed for up to two years or fined up to $10,000 or both.