Every drug in your medicine cabinet passed through a Phase I clinical trial before it reached you. This first-in-human testing phase is where the journey from laboratory discovery to approved medication begins.
What Is the Goal of Phase I?
Phase I trials are designed to answer safety questions: – Is the drug safe for humans at any dose? – What dose can be given before side effects become unacceptable? – How does the body process the drug (absorption, distribution, metabolism, excretion)? – How long does the drug stay active in the bloodstream?
Phase I is not designed to prove whether the drug treats a disease, that comes later.
Who Participates?
For most drugs (outside of oncology), Phase I participants are healthy volunteers, people with no major medical conditions who receive the experimental drug to assess how the body handles it.
For cancer drugs and severe conditions, Phase I trials may involve patients with the disease, since healthy volunteers cannot ethically receive experimental cancer therapies.
How Phase I Trials Work
Dose escalation: Phase I begins with a very small group (3–6 participants) receiving a very low dose. If well tolerated, the next group receives a higher dose. This continues until a maximum tolerated dose (MTD) is established.
Close monitoring: Phase I participants are often observed for hours or days after dosing. Blood is drawn at multiple time points to measure drug levels.
Small scale: Phase I typically involves 10–80 participants total.
Phase I vs. NuLine’s Studies
NuLine conducts Phase II and Phase III clinical trials, where safety has already been established and effectiveness is being evaluated. These are more applicable to patients with specific conditions such as atopic dermatitis, kidney disease, acne, or iron deficiency.
See our current active studies or learn more about participation.