Trial Phase

Fase del Ensayo

In 9 languages

LanguageTerm
EnglishTrial Phase
Spanish (Español) Fase del Ensayo
Chinese (中文) 临床试验阶段
Korean (한국어) 임상시험 단계
Vietnamese (Tiếng Việt) Giai đoạn Thử nghiệm Lâm sàng
Filipino (Tagalog) Trial Phase
Portuguese (Português) Fase do Ensaio
Thai (ภาษาไทย) ระยะการทดลองทางคลินิก
Japanese (日本語) 臨床試験フェーズ

What it means

Clinical trials are conducted in four sequential phases. Phase I trials test a new treatment in a small group (20–100 people) to evaluate safety, dosage range, and side effects. Phase II trials expand to more participants (100–300) to assess effectiveness and continue safety evaluation. Phase III trials involve large numbers (1,000–3,000+) comparing the new treatment against standard care—successful results are typically required for FDA approval. Phase IV trials occur after approval to monitor long-term effects and rare side effects in the general population. Knowing the trial phase helps you understand what is already established about the treatment's safety and effectiveness.

How to say it

Sentences a patient might use with a doctor, nurse, pharmacist, or insurer:

TRY-ul fayz

fase del ensayo

Also called 'phase of the trial' or 'study phase'

También llamada 'fase del estudio' o 'fase clínica'

ClinicalTrials.gov lists the phase in each study record

'ClinicalTrials.gov lista la fase en cada registro de estudio'

Where you'll see it

ClinicalTrials.gov study recordsClinical trial informed consent formFDA drug approval documentationOncology treatment plans

Related terms

Sources

US Glossary Español A–Z US Codes United States

Last reviewed: September 2026