Nairobi, Kenya - Unregulated clinics offering backstreet skin-bleaching injections have become increasingly popular with Kenyan women - a trend that health professionals find alarming.

Nairobi's River Road, a bustling area with a reputation for prostitution, black market goods and crime, has become a hub for illicit beauticians that provide these injections - often sitting outside their shops or booths hissing at passing women to attract customers.

Dubbed "Kenya's Kim Kardashian", the supermodel Vera Sidika recently sparked a national debate when she unapologetically spoke out on national television about undergoing expensive skin-whitening treatment in the UK - saying she spent the equivalent of $170,000 on the transformation, which started the viral hashtag #BleachedBeauty on Twitter.

"My body is my business and it is a money maker," she says. "Change is good - if you do it the right way."

Operating a small booth in the River Road area, Rose has worked in the skin-lightening business for more than five years. A range of skin-bleaching creams is displayed outside the booth. Rose also offers inside injections, but only to clients she trusts. She says injecting is considered taboo, but the process could lead to more effective results than other techniques.

"If you want an even colour and fast results, injecting is much better than a cream," says Rose, who gave only her first name fearing police arrest. "Some girls go back to their village and tell them the water of Nairobi made them lighter. There is great shame for wanting to change what God gave you."

Though black-market beauticians say their products go through a safe and effective process, medical professionals warn the increasing popularity of these unregulated injections could cause health problems in the long term.

The skin whitening industry is worth billions of dollars [EPA]

'Big money to be made'

Many of the products injected into River Road clients come from unregulated and imported materials from countries such as the Democratic Republic of Congo and China. Some list dangerous chemicals among their ingredients, including alpha hydroxyl acids (AHAs), a type of corrosive compound used in chemical peels.

"They promise the injection is safe, but it is not," says Dr Pranav Pancholi, a Harvard-trained dermatologist who works at Kenya's Shah Hospital. "The products are packaged and marketed to look attractive, but anything could be inside. Injecting products containing AHAs is abnormal. It can kill body tissue and cause serious infection."

Dr Adam Friedmann, a dermatologist at London's Harley Street Dermatology Clinic, agrees that the increasing popularity of the injections is a worrying trend.

"With bleaching creams from places like China and Africa there is no quality control. Bleaching creams contain dozens of chemicals, most of which are not labelled. Unregulated creams could - and often do - contain powerful steroids. They can cause thinning and skin damage."

Friedmann says badly administered injections of unregulated substances could also result in HIV, Hepatitis C, TB, permanent disfigurement, inflammation or critical infection - but those seeking whiter skin continue to purchase them if they hear of short-term positive results by word of mouth.

"People will take anything they think works," Friedmann says. "In the beauty industry, you can only go by anecdotal evidence. The effectiveness of such products is often subjective ... If people report positive results then the product sells. There is big money to be made if people are injecting such creams."

'Whitenicious' pop star treatment

Though a relatively new phenomenon, the use of skin-bleaching creams has long been popular in Kenya and other African countries, including the Democratic Republic of Congo and Nigeria.

My body is my business and it is a money maker. - Vera Sidika, model

The Anglo-Dutch consumer goods company Unilever sells the world's most popular skin-whitening treatment, a cream called Fair & Lovely. It is heavily advertised across Africa, Asia and the Middle East and boasts on its website that "250 million consumers across the globe strongly connect with Fair & Lovely as a brand that stands for the belief that 'beauty that empowers a woman to change her destiny'".

The rising popularity of dangerous skin-bleaching injections in Kenya comes as a number of high-profile Africans have started openly talking about changing their skin colour for beauty reasons - defying taboos.

In January, Cameroonian pop star Denicia spoke openly about her own skin-whitening treatment and launched a brand of skin cream called Whitenicious, which sold out within 24 hours.

The appearance triggered a national debate on skin whitening on social media, and attracted heavy criticism from some quarters. Orie Rogo Manduli, a former Miss Kenya and an advocate for womans' rights, named Sidikia "the most despicable woman we have ever had in this country", and called for a media blackout on her activities to "protect our young girls from her bad influence and misguided ways".

Sidika responded by saying she should be respected as a self-made woman from a poor background.

"It is ... society that is promoting the skin lightening or bleaching," she says. "When you ... walk into modelling agencies, the girls there who get picked up for jobs are usually fair-skinned."

She also scorned the backstreet treatments offered on River Road, saying the practitioners there were offering low quality "skin bleaching" that could do harm.

Worth it?

For most Kenyans their budget to pursue whiter skin is much lower than Sidika's, but spending on illicit backstreet treatments can still represent a serious investment in a country where UNICEF says more than half the population lives on less than $1 a day.

Rose charges $70 per shot and says the treatment can require a number of visits before results begin to show.

My husband prefers half-caste women to darker girls, and he is proud to be mine when we go to the club. - Mercy, skin bleaching client

The promise of whiter skin is worth the investment, according to one of Rose's clients, a woman in her mid-20s who also sells skin creams and gave her name as Mercy.

She says she has been using lightening creams for a number of years and is trying the injections in an attempt to get more dramatic results.

"My husband prefers half-caste women to darker girls, and he is proud to be mine when we go to the club," she says. "I get far more male attention now I am lighter."

Though medical professionals have serious concerns about the increasing popularity of the skin-bleaching injections, institutionalised corruption in Kenya's security forces means police are reluctant to intervene to stop the practice.

Pancholi says skin bleachers operating on River Road make regular payments to the police, and a crackdown on their businesses is unlikely.

"It is illegal for a non-medic to inject a client, but bribery allows the trade to continue," he says.