A control is the standard by which experimental observations are evaluated. In many clinical trials, one group of patients will be given an experimental drug or treatment, while the control group is given either the standard treatment for the illness or a placebo. A blinded or masked study is one in which participants do not know whether they are in the experimental or control group in a study. Those in the experimental group get the medications or treatments being tested, while those in the control group get the standard treatment or no treatment. These studies are performed so neither the patients' nor the doctors' expectations about the experimental drug can influence the outcome.
Side effects are any undesired actions or effects of a drug or treatment.
Negative or adverse effects may include headache, nausea, hair loss, skin irritation or other physical problems. Experimental treatments must be evaluated for both immediate and long-term side effects. There are both benefits and risks associated with clinical trials. Gain access to new treatments that are not available to the public. Obtain expert medical care at leading health care facilities during the trial.