In November 2008, children in Nigeria taking a medicine called My Pikin Baby Teething Mixture began to die. The syrup was counterfeit, the standard glycerin replaced with cheaper diethylene glycol, which looks, smells and tastes the same. But diethylene glycol is an industrial solvent, which attacks the central nervous system, kidneys and liver. The medicine killed 84 children before it was pulled from pharmacy shelves.

PhD Innovation Program graduate Ashifi Gogo

Counterfeit medicine sometimes kills outright, as My Pikin did. More frequently, it kills by robbing patients of the real drugs they need. And some counterfeits contain a small amount of active ingredient — not enough to cure an illness, but enough to promote resistance that renders even the real medicine powerless. That might be the most deadly effect of all. ...

... While working on a doctorate at Dartmouth, Ashifi Gogo, who was born in Ghana, developed a bar code system that allowed shoppers to verify that produce sold as organic truly was. “Everybody loved it. It won a number of awards — and got zero market traction,” he said. “Nobody wanted to buy it, because they trust Whole Foods.”

Then Gogo started to look for places where that trust is absent. “In emerging markets, customers don’t really trust the shop,” he said. “We switched from 2-D bar codes to scratch-off labels, and from kiosks and high-end scanners to cellphones.” Sproxil makes labels that its clients affix to blister packs inside each box of medicine. Each label has a unique scratch-off ID number. Purchasers text the ID to a number on the box, and instantly get a text back saying whether the medicine is fake or real.

Sproxil made its debut in 2010 when Biofem pharmaceuticals in Nigeria tried the system to authenticate Glucophage, a drug for diabetes that had lost significant market share due to counterfeiting. A three-month pilot had a 10 percent increase in sales.

Today Sproxil works in Ghana, Kenya, Nigeria and India, and is expanding into Latin America and farther into Asia. About half its clients are pharmaceutical companies. The others make auto parts, cables, mattresses, agrochemicals or even underwear.

Sproxil is by far the biggest company in the mobile verification business, with more than 9 million verifications so far. One reason is that in most countries, its verification texts are free. Gogo said that setting up that arrangement with cellphone service providers has been a nightmare. “The phone companies advertise very fast network speeds on their TV spots but they have molasses-grade administration,” Gogo said. “It can take a year for them to provide lifesaving service to their own customers.”