First Published: January 2005
Last Reviewed: January 2005
Peer Review Status: Internally Peer Reviewed

Understanding the "placebo effect" can help you have clearer expectations about the benefits of taking medications.

A placebo is an inactive substance or "sugar pill." Say there's a clinical study on a daily medication to prevent bone fractures in older women. Each participant is randomly assigned to one of three groups: those that receive nothing, those that receive a placebo pill and those that receive a real pill. Women getting a pill don't know whether it's real or not.

Results show that within a year, four out of 20 women not taking anything will get a fracture, three out of 20 women taking a placebo will get a fracture, and two out of 20 women taking an actual pill will get a fracture. The difference between those taking nothing and those taking placebo is the placebo effect: taking the fake pill somehow decreases the chance of a fracture.

The results also mean that out of 20 women taking the actual medication, only one additional person will have a positive outcome compared to those on placebo. In a way, that is a very small difference.

So, some women will have a fracture no matter what they do; but most will not get a fracture no matter what they do.

Testing for the placebo effect makes the study more honest. You probably don't ask for details about medication study results--including limited benefits--when your doctor prescribes a pill. And the doctor normally doesn't share results, in part because of time constraints.

So is taking the actual pill beneficial or not?

If there are treatments of scientific value, a doctor should use them or tell patients about them. If the only thing the doctor can provide a patient is a placebo effect, then it is ethical to use that means. But a doctor cannot use only the placebo effect when other treatments are available--it would not be ethical.

However, prescribing a real pill, even one with limited benefits, may maximize the placebo effect. Being prescribed a pill may make you feel "taken care of." Thus, the placebo effect can involve hopefulness.

Numerous studies have shown apparent neuroendocrine (chemical) benefits of positive thinking, relaxation or prayer on various disease outcomes. A study on children with cancer showed that those who played video games that allowed them to "zap" tumor cells had better outcomes than those who did not play games. Perhaps this is the scientific reason behind a "placebo effect."

The placebo effect also can involve changes in behavior. Being prescribed a medication gets your attention. Now that you're taking an actual pill, you might be more compliant with other physician recommendations such as, in the case of bone health, taking vitamin D and calcium.

As another example, the placebo effect plays a role in weight loss efforts. If your doctor wants to help you lose weight, he or she may schedule you for a return appointment. The doctor doesn't give you a drug, but having you come in again holds you accountable.

In short, the placebo effect can help you use your own resources and maximize what you bring to healing yourself.