Phase 1 Clinical Trials: The Complete Guide
✍️ By PayTrials Editorial Team — Last reviewed March 2026
Understanding the highest-paying clinical research studies
✍️ By PayTrials Editorial Team — Last reviewed March 2026
Understanding the highest-paying clinical research studies
Phase 1 clinical trials represent the first stage of testing new drugs or treatments in humans. After years of laboratory and animal studies, researchers need to understand how a compound behaves in the human body—how it is absorbed, distributed, metabolized, and excreted. These first-in-human studies focus primarily on safety, not effectiveness.
Phase 1 trials typically involve small groups of 20 to 80 healthy volunteers (or sometimes patients with a specific condition, depending on the drug). The primary goals are to determine the highest dose that can be given safely, identify side effects, and observe how the drug moves through the body. Participants are closely monitored throughout the study.
Because Phase 1 trials are the first time a drug has been given to humans, they require the most intensive monitoring. This often means overnight or extended stays at a research facility, frequent blood draws, and continuous vital sign tracking. That level of commitment is why Phase 1 compensation tends to be the highest in clinical research.
Compensation for Phase 1 trials ranges from approximately $5,000 to $45,000 or more. The higher end reflects studies with longer inpatient stays, more frequent procedures, and greater time commitment. A 28-day inpatient study with multiple blood draws per day can pay $25,000 to $45,000, while a shorter 5-day stay might pay $5,000 to $8,000.
Several factors drive these compensation levels. Time commitment is significant—many Phase 1 trials require you to live at the facility for days or weeks, during which you cannot work, travel freely, or maintain your normal routine. Inpatient requirements mean 24/7 accommodation and meals, but also confinement to the research unit.
Blood draw schedules can be intensive, with samples taken at multiple timepoints to track how the drug behaves. Close monitoring includes frequent vital sign checks, ECGs, and physical exams. The combination of time, inconvenience, and procedural burden justifies the premium compensation. For more on trial compensation, see our guide to clinical trial pay.
Eligibility for Phase 1 trials is typically strict. Most studies require healthy volunteers within a specific age range (often 18–55 or 18–65), with a BMI between 18 and 30. You generally must be a non-smoker or have quit at least 6 months prior. Many studies exclude anyone on prescription medications for 14 to 30 days before screening.
Medication restrictions extend to over-the-counter drugs, supplements, and herbal products. Certain health conditions—such as hypertension, diabetes, thyroid disorders, or cardiovascular disease—often disqualify applicants. You may need to have abstained from blood donation for at least 56 days and from alcohol for a specified period before screening.
Washout periods are common: if you've participated in another clinical trial recently, you may need to wait several months before qualifying for a new study. Each protocol has unique criteria, so read the inclusion and exclusion requirements carefully before applying. Our qualification guide offers detailed preparation tips.
Inpatient stays are the norm for many Phase 1 studies. You'll check in at the research facility and remain on-site for the duration of the confinement period. Facilities provide private or semi-private rooms, meals, and amenities such as Wi-Fi and entertainment. You'll follow a structured daily schedule with designated times for drug administration, blood draws, meals, and rest.
Blood draws occur at specific intervals—often every few hours in the first 24–48 hours after dosing—to measure drug levels in your bloodstream. Vital signs (blood pressure, heart rate, temperature) are monitored frequently. Meals are typically provided and may be standardized to control for food effects on drug absorption.
Accommodations vary by facility but generally include beds, bathrooms, and common areas. You can usually bring electronics, books, and personal items. Visits from family may be restricted during certain phases of the study. For a deeper look at the process, read our article on how clinical trials work.
Phase 1 trials operate under FDA oversight and require IRB approval before enrolling a single participant. Institutional Review Boards evaluate the study design, informed consent process, and risk-benefit balance. The FDA can halt any trial if safety concerns arise.
Medical staff are on site 24/7 during inpatient studies. You have the right to withdraw at any time, for any reason, without penalty. Informed consent is required before any procedures, and you must understand the potential risks before participating. While all medical research carries some risk, Phase 1 healthy volunteer trials have established safety records.
PayTrials aggregates Phase 1 and other clinical trials in one searchable database. Browse studies and filter by compensation, location, and study type to find Phase 1 opportunities near you. Create a profile to save studies and receive alerts when new trials match your criteria.
The screening process typically starts with a phone or online pre-screening. If you meet basic criteria, you'll be invited for an in-person screening visit including a physical exam, blood and urine tests, and an ECG. Results determine final eligibility. To maximize your chances, ensure you meet the health requirements, avoid restricted substances in the weeks before screening, and respond promptly when new studies are posted.
Phase 1 clinical trials typically pay between $5,000 and $45,000 or more, depending on the study duration, number of overnight stays, and procedures required. Shorter outpatient studies pay less, while multi-week inpatient stays pay the most.
Most Phase 1 trials require healthy volunteers with no significant medical conditions. Researchers need a clean baseline to accurately measure how the study drug affects the body. Some Phase 1 trials do recruit participants with specific conditions.
Phase 1 trials are FDA-regulated and IRB-approved. Medical staff are on site 24/7 during inpatient stays. You have the right to withdraw at any time. Serious adverse events in Phase 1 healthy volunteer trials are rare, though all medical research carries some risk.
Phase 1 trials vary from a few days to several weeks. Inpatient stays typically range from 3 to 28 days, with follow-up visits over subsequent weeks or months. The compensation amount usually reflects the total time commitment.
Common disqualifiers include: BMI outside the typical 18-30 range, smoking or nicotine use, prescription medications, recent blood donation, certain chronic conditions, and abnormal lab values. Each study has specific criteria—review them before applying.