Open-label trial

---

title: "Open-label trial" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["design-of-experiments", "clinical-trials", "scientific-method", "research-methods"] description: "Clinical trial where the treatment isn't hidden" topic_path: "general/design-of-experiments" source: "https://en.wikipedia.org/wiki/Open-label_trial" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Clinical trial where the treatment isn't hidden ::

An open-label trial, or open trial, is a type of clinical trial in which information is not withheld from trial participants.{{cite web |url=https://www.cancer.gov/publications/dictionaries/cancer-terms/def/open-label-study |title=Open label study|publisher=National Cancer Institute, US National Institutes of Health|date=2020|access-date=20 November 2020}} In particular, both the researchers and participants know which treatment is being administered.

Open-label trials may be appropriate for comparing two similar treatments to determine which is most effective, such as a comparison of different prescription anticoagulants, or possible relief from symptoms of some disorders when a placebo is given.

An open-label trial may still be randomized. Open-label trials may also be uncontrolled (without a placebo group), with all participants receiving the same treatment.

References

References

1. (2020). "Double-blind (trial)". Merriam-Webster Medical Dictionary.
2. (2020). "Double-blind study". HIV.gov, Office of AIDS Research, US National Institutes of Health.
3. (2011). "External and internal validity of open label or double-blind trials in oral anticoagulation: better, worse or just different?". Journal of Thrombosis and Haemostasis.
4. (25 May 2017). "Open-label versus double-blind placebo treatment in irritable bowel syndrome: study protocol for a randomized controlled trial". Trials.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::