"Street medication kills. The street is killing (safe) medication," declares a banner outside a pharmacy in the Cameroonian capital Yaounde, where the dangerous trade is rampant.
The market is saturated with counterfeit anti-malaria drugs, painkillers, antibiotics and even rehydration serum. No domain of the pharmaceutical industry is spared by illicit manufacturers and traffickers, according to reports gathered by AFP offices across Africa.
"That's powerful Diclofenac (an anti-inflammatory), which is the bestseller," says Blaise Djomo, a street vendor at Yaounde's central market. "And this is Viagra, which Cameroonians are really wild about."
Pills freely available at markets
About 100 traders like Djomo are set up under parasols in full view of everyone, their boxes heaped with medicines. Bubble-pack strips of pills are lined up in the wooden stalls.
People can even buy single pills at this market or even at some grocery stores. Vendors often mix fake medication with the real thing, which has either been legally acquired or stolen from supplies meant for hospitals and clinics.
At best, fake prescription drugs have no effect, acting like placebos, but at their worst, they are highly toxic. Either way they bring in vast sums of money for those behind the illicit traffic.
The UN Office on Drugs and Crime (UNODC) warned at a conference last February that counterfeit drugs are a multi-billion dollar business accounting for 30% of the pharmaceutical market in parts of Africa.
"Fraudulent medicines have proven to be harmful and at times fatal, as well as an increasingly lucrative area for organised criminal networks," the agency said in a press release.
"The supply routes are of two kinds. Alongside the small-scale smugglers, there are international criminal networks that undertake the supply of drugs from distant manufacturers in China and India," said Parfait Kouassi, who chaired the National Order of Pharmacists in Ivory Coast from 2005 to 2012.
30% are fake
Kouassi, who made a priority of fighting the dangerous trade in fake medicines, escaped two murder bids at the headquarters of the Order of Pharmacists. "That's a sign that major interests are in play and that it's not just a matter of small-scale local traffickers," he said.
The phenomenon is spreading and represents between 20 and 25% of the drug market in Ivory Coast, adds Kouassi. In Kenya, 30% of drugs sold in 2012 were either fake or counterfeit, according to the Pharmacy and Poisons Board of Kenya. Cameroon health officials give a similar figure.
However, in the Democratic Republic of Congo, as in many other African countries, there are no national statistics, just records of frequent drugs seizures.
In Nigeria -- once known as a major source of counterfeit medicines -- phony drugs and real ones that had passed their expiry date made up 70% of sales in 2002, according to the World Health Organisation.
Since then, in the continent's biggest market with some 160 million people, officials say that high-profile efforts have greatly reduced the number of fake or adulterated drugs, but reliable figures are hard to obtain.
"Most of these fake and adulterated drugs come from China and India, from where we import more than 50 percent of the drugs we use in Nigeria. We don't import much drugs from the US," says Abubakar Jimoh, spokesman of the National Agency for Food and Drug Administration and Control (NAFDAC).
"They no longer bring ... illicit drugs in large containers but in small packs. They also change the labels of the drugs from outside the country to make them look original," Jimoh said.
Health authorities have set up a service to enable consumers to check the authenticity of drugs by verifying the PIN serial number on the product label via an SMS message.
Safe vs. cheap: the cost factor
The outstanding exception on the continent in fighting the illicit drug trade is South Africa, which has a strictly enforced licencing system, according to Griffith Molewa, head of law enforcement at the Medicines Control Council.
"We have dedicated ports of entry for medicines, restricted to Durban, Cape Town, Port Elizabeth and OR Tambo airport in Johannesburg," Molewa said. "We also have a vertically integrated system, meaning only manufacturers can sell to the wholesalers, and then the wholesaler to the retail outlets, and then the pharmacies can only serve the patients."
"Any product found on the street is seized and given to the police for prosecution. The penalty is a fine or up to 10 years of imprisonment or both."
In most other countries, measures against the counterfeit drug trade are limited to police raids on public markets to seize fake or adulterated products, along with public information and awareness campaigns, which appear to have little effect on consumers.
For in countries where medical expenses -- from drugs to hospitalisation -- are not even partly reimbursed by the state, the relatively cheap price of street medication trumps the risk factor for many.
"I'm here to buy a worm treatment and something to protect my children from malaria," customer Nadine Mefo told AFP at Yaounde's central market. "It costs less than in the pharmacy and it soothes the children.
"Doctors say that street market medicines are dangerous, but since I've been coming, I've not yet had a problem," she adds, clutching two packs of pills of unknown origin.