It is a familiar formula for persuading women to buy a new beauty product: plaster billboards of a beautiful model in the capital city, accompanied by a catchy slogan written in the language of the ordinary woman.

But when new adverts for skin cream Khess Petch – a skin-lightening cream whose name means "all white" – appeared in Senegal, they had the exact opposite effect. The ads, which boasts extreme skin-whitening after 15 days, complete with dramatic before and after shots, provoked mass public outrage and calls for the government to introduce an industry-wide ban.

"We are used to seeing adverts for skin-lightening, but when we first saw these adverts for Khess Petch we were really scandalised. We decided to act," said Aisha Deme, manager of an online events website in the Senegalese capital, Dakar.

"Society is constantly telling us that fair-skinned women are beautiful – in the media, on TV – and Senegalese women have started to believe it," Deme added. "So we want to show that dark-skinned women are really beautiful, and that natural black skin should be celebrated."

Deme is co-ordinating a campaign called Ñuul Kukk – which means "pitch black" in local language Wolof – and has attracted thousands of supporters on Facebook and high-profile friends, including the actor Awa Sene Sarr and rapper Awadi.

Senegal's health minister, Eva Marie Coll Seck, has also met the group and expressed her "outrage" about the adverts.

Dr Fatou Fall, a dermatologist from the institute of social hygiene in Dakar, said: "Skin complexion matters [Many women believe that] women with fair skin are more successful, women with fair skin are the ones who stand out."

Dermatologists say that many of the products include steroids such as clobetasol propionate, a cream that should be used for the treatment of severe skin inflammation and prescribed by health professionals, and hydroquinone, a potentially carcinogenic chemical that limits melanin production in the skin, and is banned in the EU.

Although Senegalese law includes controls over the creams, including a ban on creams with more than 2% corticosteroid, the laws are poorly enforced, with products with much higher levels freely available in stalls and marketplaces in Dakar.

Critics say that the cost of Khess Petch – at 1,000 CFA francs a tub – less than £2 – deliberately targets women who are unaware of the risks.

"There are expensive face-lightening creams which are less dangerous, but products like Khess Petch are very cheap and very dangerous – they are deliberately targeted at women in the villages and the poor urban areas," said Deme. "Even when they discover the side-effects and want to stop using the creams, they find they cannot stop. It's only when you stop that the skin changes and begins to become completely burned."

"When women who use these creams stop, they look horrible," said Fall. "They actually start looking more black, all the side effects manifest at the same time, which they just can't accept."