Millions of Americans face an impossible decision each month. They must choose between paying for food or medication they need to keep their children or themselves alive.
One study conducted by the health policy organization, The Commonwealth Fund, found that 48 million Americans chose not to fill prescriptions in 2010 because of the cost.
The result is a black market for prescription medication that has doctors and other health advocates worried.
"The most concerning thing for a physician, for us at the poison center is that maybe the quality isn't the same," said Dr. Frank LoVecchio, who is the co-medical director of the Banner Poison and Drug Information Center.
LoVecchio told CBS 5 Investigates that the black market lends itself to drugs for chronic conditions, which need to be taken every day.
People like Lucia Maya, who has lived with Type One Diabetes since she was 12 years old, know the cost associated with needing to take medication several times per day. She is a Reiki instructor, who owns her own business and does not have insurance.
"It means I have to buy all of my medications, my testing supplies, anything that I use to keep alive I have to pay for and it's expensive," said Maya.
Maya purchases her insulin from an online pharmacy located outside the country. She said it helps her keep expenses down. Those expenses would easily top $500 per month without her efforts to buy her medication outside the normal channels.
Although she uses due diligence to make sure the pharmacies she uses are reputable, she has received warm insulin in the mail before. When insulin becomes warm, it loses its effectiveness.
Earlier this year, the FDA moved to shutter more than 1,600 online pharmacies the agency alleged were selling counterfeit, substandard and in some cases, fake medications.
The black market is also fed with medications that were stolen in multi-million dollar heists and robberies. The total value of stolen pharmaceuticals reaches into the tens of millions of dollars in the United States each year.
A CBS 5 Investigation found insulin and asthma medication for sale on Craigslist here in Phoenix.
One seller said he gets his with his insurance and sells any extra he has left at the end of the month.
"I give them a deep enough cut to where anyone can afford to come, you know, buy it if they need it," said the seller, who charged $35 dollar for a bottle of insulin that would normally sell for $125.
In Arizona, it is illegal for anyone outside of a licensed pharmacy to sell any injectable drugs. The seller said he understands the consequences.
"I know that there's a lot of people out there that can't afford to buy their insulin. And I've been there," he said.
If you have any questions about the medications you have purchased online, on the street or in a normal pharmacy, click on this link for a website that can help distinguish between legitimate medications and counterfeits.
Dr. LoVecchio from the Banner Poison and Drug Information Center said buyers should avoid purchasing any drug from an unknown source, but especially drugs that can be easily tampered with or diluted. He mentioned capsules and vials of intravenous medications.
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