When Nikolai Sopko walks into a medical testing facility, it's usually not because he's sick. And it's not to practice his burgeoning skills as a medical student. It's for part-time work as a professional human guinea pig, a gig he shares with many. From college campuses to crowded Indian hospitals, researchers are always searching for people to take part in medical tests. Sometimes they're willing to pay big bucks, sometimes not.

Rebecca Meiser, writing for the Cleveland Scene, profiles a few of the people who have made thousands of dollars as test subjects. One willing participant is Bob Helms, who started the zine Guinea Pig Zero as a journal for subjects of research tests. It's now a clearinghouse for information, testimonials, and even poetry by and for people who take part in medical research. 'For us, it's just a job,' Helms says of himself and his colleagues. 'As with any other jobs, you've just gotta be aware of what you're getting into.'

But Helms has a luxury that many test subjects do not have: If he doesn't like the look of a certain experiment, he doesn't have to take part. Others don't have that choice. The history of medical experimentation is filled with incidents like the Tuskegee Syphilis Study, where black men with syphilis were denied treatment in the name of science. Such abuses don't seem like history when compared to the relatively recent scandal of the 'guinea pig kids,' where New York orphanages and foster homes used HIV-positive children as subjects to test experimental AIDS drugs. There are laws and regulations in place to protect human test subjects, but Jeffrey Kahn of Seed Magazine points out that much of the regulation applies only to public research, leaving private research largely unregulated in an 'obvious shortcoming' he calls on Congress to resolve.

Even with improvements to the American system, if the laws of the United States get too restrictive, companies can always go abroad. Jennifer Kahn of Wired reports on the many poor and illiterate people in India who are essentially sold to medical science. 'Patients here are very passive,' says S. P. Kalantri, a doctor in India. 'They will almost never question their doctor.' Knowing this, the Indian government has recently loosened its laws to allow for more medical experimentation and to attract more dollars from Big Pharma.