What is a Placebo?  

A placebo is an alternative “medical treatment” used in double-blind randomized controlled trials to determine if a new treatment being studied works better than no treatment (A.K.A. a control). Placebos are also used to blind study participants and investigators so that neither group knows which treatments are assigned to which participants. A placebo could be a pill, a shot, or any other “treatment” that does not contain any active health-affecting substance.

Key Takeaways

  • Concierge medicine models provide patients with unlimited access to primary care services for a monthly or annual fee. 

  • Concierge medical fees only provide access to primary care, so patients need additional insurance plans to cover non-primary care health needs.

  • These practice models could be cost-effective for patients who require frequent primary care visits.

What is a Placebo

What makes a placebo?

A placebo is a compound that resembles an experimental treatment without containing any active medication. For example, if a cancer-fighting drug is delivered as an orally ingestible pill, the placebo would be an orally ingestible pill of similar size and composition without any active drug in it. There are two reasons for this:

  1. To properly assess the effect of the experimental treatment on humans by preventing external factors from affecting the comparison between placebo and experimental groups.

  2. To prevent participants or investigators from being unblinded. If a participant becomes aware of the study arm they are randomized to, it may result in non-compliance or loss to follow-up bias. 

What is blinding?

Blinding refers to the act of intentionally masking the nature of the treatment that participants receive in an RCT to eliminate bias. 

An RCT can be either single-blind or double-blind. A single-blind study is one in which the participants are blinded to the exposure they receive. A double-blind study, aka the gold standard, is one in which both the participants and the investigator are blinded to what treatments participants receive. 

Blinding is done by isolating study participants, those involved with their clinical management, and those analyzing collected data from knowledge of study design and treatment assignments. The use of placebos also helps with blinding, since they’re similar to the treatment but have no true effect. 

The infamous placebo effect

The placebo effect occurs when a subject given a placebo treatment behaves as if there is an effect. Common conditions for which the placebo effect influenced clinical trial data are migraines, cancer-related fatigue, and depression. 

A battle of ethics 

The use of placebos in clinical trials is a controversial topic. Opponents argue that it is unethical to give subjects an ineffective treatment when an effective treatment may exist. In addition, subjects with chronic diseases are at risk of health deterioration if they receive a placebo treatment during the trial period. Proponents of placebo use argue that placebos are needed as controls to properly assess the efficacy of a new treatment. 

Active Treatment vs. Placebo

An alternative to a placebo-controlled clinical trial is an active control group trial, where one group of participants receives the treatment being studied and the control group receives an alternative standard treatment. Using active control eliminates the ethical issues that arise with placebos but could also, by introducing new external factors, compromise the scientific integrity of the trial.


Outside the Huddle


Reviewed by Geetika Rao, MPH | Edited by Nidhi Mahagaokar, MPH | Fact checked by Jared Dashevsky, M.Eng.