In some clinical research studies, the medical facility conducting the research pays for your treatment and other expenses. In other trials, you may be responsible for costs. Be sure to ask about possible expenses. Specifically:You or your health insurer may have to pay for some costs of your treatment that are considered part of standard care. This may include hospital stays, laboratory and other tests, and medical procedures. If you have health insurance, find out exactly what it will cover. If you don't have health insurance, or if your insurance company will not cover your costs, talk to the researchers or their staff about other options for covering the cost of your care. You also may need to pay for travel between your home and the clinic.
This answer is based on source information from National Institute of Mental Health.