BOKSBURG, South Africa — Mpho was a bored teenager growing up in the bleak sprawl of big city Johannesburg, with few opportunities and little to do for fun.

When a friend offered her “nyaope,” she didn’t say no.

“I wanted to feel happy,” she said, recounting her first experience smoking the cocktail drug. “And I felt so happy and so high — I had never had felt such a thing before.”

Nyaope, also called "whoonga," is the street drug that is ravaging South Africa’s impoverished townships. Cheap and highly addictive, it is said to include marijuana, low-grade heroin and other additives like rat poison and antiretrovirals, which are used to treat HIV.

The details of nyaope are local, but the story has become universal. Nasty, low-cost cocktail drugs are a growing problem in many parts of the world. “Krokodil” — a mix of codeine and gasoline, so named for the flesh-destroying skin condition it causes — is reported to have recently spread from Eastern Europe into the United States.

In South Africa, nyaope is popular among lower income groups in the townships surrounding Johannesburg and Pretoria, areas already facing high unemployment and poverty. Nyaope only emerged in the last six or seven years but is widely available, costing just 30 rand ($3) for a hit.

The drug has drawn national attention here in South Africa. President Jacob Zuma warned earlier this year that the nation's young are becoming “slaves of drugs such as nyaope,” contributing to increased crime and domestic violence.

He's not wrong.

After trying nyaope in high school, Mpho quickly became addicted and fell into a cycle of stealing and selling her body to make money to buy the drug. For about three years Mpho lived with her dealers, who pimped her out to customers.

“Nyaope, if you’re a girl, can lead to many things,” she said. “You will do things that you never thought you would do.”

Cathy Vos, coordinator of the South African National Council on Alcoholism and Drug Dependence (SANCA), said that use of nyaope is already an enormous problem, and only getting worse.

One SANCA-run rehab clinic, in Vereeniging near Johannesburg, reported 63 people undergoing treatment for nyaope addiction in April. In June there were 134 people, while in August, 223 people sought assistance.

“It is increasing tremendously,” Vos said.

Vos said the rapid growth in nyaope use has left SANCA — a non-profit organization that receives funding from the South African government — with too few resources to address the problem.

There are waiting lists for treatment programs, and shortages of medicine to help with withdrawal symptoms.

“Many of our patients are HIV positive, so you will have an HIV-positive person who has not been diagnosed or treated and is now using nyaope and his health deteriorates very past,” Vos said.

“Because of their poor health, in the withdrawal stage, they really suffer.”

Unlicensed rehabilitation centers are mushrooming in the area around Johannesburg to meet the demand from families desperate for help.

The provincial minister of social development has described these illegal clinics as a threat to drug addicts, rather than a help. At some clinics investigated by the ministry, patients were confined to small rooms without access to professional care, and were even used for hard labor.

Mpho, who is now 23, is about to complete six weeks of rehab at the respected Horizon Clinic in Boksburg, near Johannesburg.

Like other patients there, she asked for her privacy to be protected. A petite, confident young woman, Mpho said she underwent treatment in order to “live a normal life” for her 2-year-old daughter.

“I’m relieved, happy, excited. Scared to face the world. But I will fight,” she said.

Sipho, 17, who is also in rehab at the Horizon Clinic, said he started smoking nyaope a year ago after a friend offered him a joint.

Within months he had quit high school and felt such terrible withdrawal symptoms that he began stealing from people in the community to finance his habit.

When his neighbors caught him stealing, they would beat him in public.

“They were cruel,” he said. “My mouth was bleeding so much I couldn’t eat. I hurt all over.”

When Sipho leaves the clinic, he will move in with an aunt in a different area, to get away from his old friends.

“I am so nervous about going home,” he said.