Before medications are released to the general public, they undergo rigorous testing on human test subjects -- paid volunteers who participate in experimental treatments. These studies may be as simple as visiting a testing facility a few days a week while taking medication or as complex as staying in a facility full-time for weeks, so you can participate as much or as little as you like. If you are trying to pick up some extra cash and you aren't afraid to have blood drawn, participating as a medical test subject may be for you.
Use a website that aggregates listings for test subjects. Medical science companies that sponsor or conduct clinical trials often list their available trials online, and sites like "GPGP" and "Just Another Lab Rat" sort and list these trials based on location.
Contact the company conducting the clinical trial. Some of these companies may not list individual trials online; instead, you may have to fill out a questionnaire and wait for the company to contact you for trials for which you are eligible.
Weigh your options. If you are choosing between multiple trials, be warned that the pay is typically commensurate with the risk. That is, better-paying trials are generally more demanding, while those that pay relatively less require less time or procedures that are medically less invasive.
Choose a trial that suits your interests. Sign up. Before you begin, you will undergo a health screening to determine your eligibility -- consider having a back-up trial in mind, in case you are ineligible for your first choice.
Universities with medical schools also may list opportunities for medical research subjects.
Many studies require only right-handed individuals.
Do not participate in more than one study at a time -- it may result in potentially dangerous drug interactions.