Randomized Controlled Trial
Abbreviation: RCT
Definition
The gold-standard study design: people are randomly assigned to the treatment or a control (such as placebo), so researchers can show the treatment caused the results.
Randomized Controlled Trial
A randomized controlled trial (RCT) is a clinical study in which participants are assigned to treatment groups by chance, for example with a computer-generated randomization sequence. Random assignment spreads known and unknown confounding factors evenly across the groups, so any difference in outcomes can be credited to the treatment rather than to differences between participants at the start. RCTs are seen everywhere as the highest level of evidence for whether a treatment works and is safe, and regulators such as the FDA require them for drug approval.
RCTs have been central to building retatrutide’s clinical profile. The Phase 2 trial was a randomized, double-blind, placebo-controlled study in which people with obesity or overweight were randomly assigned to one of several retatrutide doses or to placebo. This design let investigators measure the dose-response relationship for weight loss and blood sugar improvement while controlling for factors other than the drug, such as lifestyle changes, the placebo effect and natural variation in the disease.
An RCT is only as good as its design. It needs a sample large enough to detect meaningful differences, proper randomization to prevent selection bias, blinding to limit bias in assessment, and endpoints set in advance to avoid conclusions driven by the data. When these are done well, RCTs give the most reliable evidence for clinical decisions and regulatory review, and they are the foundation on which new treatments like retatrutide win approval for wide use.