Clinical Trials / Browse by Phase / N/A (Early Phase / Not Applicable)

Browse by Phase

N/A (Early Phase / Not Applicable) Clinical Trials

Browse currently recruiting N/A (Early Phase / Not Applicable) clinical trials registered on ClinicalTrials.gov.

Total Trials

6,885

Recruiting Now

6,885

Top Conditions in N/A (Early Phase / Not Applicable)

Stroke (113) Breast Cancer (104) Cancer (79) Obesity (68) Prostate Cancer (59) Coronary Artery Disease (51) Heart Failure (50) Cardiovascular Diseases (49) Lung Cancer (49) Healthy (49)

Frequently Asked Questions — N/A (Early Phase / Not Applicable) Trials

What does "N/A" mean for a clinical trial phase?

"N/A" or "Not Applicable" in the phase field indicates the trial does not follow the traditional Phase 1–4 drug development pathway. This applies to observational studies, epidemiological research, behavioral interventions, device studies, or exploratory work not yet assigned a formal phase. These studies are still registered on ClinicalTrials.gov and follow IRB-approved protocols.

Are N/A phase trials safe to participate in?

N/A phase trials encompass a wide range of study types, many involving minimal risk—such as observational studies, questionnaire-based research, or registry enrollment. Some may involve investigational devices or early-stage interventions. Review the trial's protocol, risks and benefits section, and informed consent documents carefully before enrolling. All ClinicalTrials.gov-registered studies must comply with applicable safety oversight requirements.

How do I find N/A phase trials for my condition?

Browse ClinicalMetric by condition to find all trials—regardless of phase—that are recruiting for a specific disease. Many N/A phase trials are observational or behavioral studies with fewer eligibility restrictions than phase-designated drug trials, making them more accessible to a broader range of participants.

Active N/A (Early Phase / Not Applicable) Studies

NCT06867185 N/A

Evaluating Therapeutic Electrical Stimulation to Improve Nerve Healing After Sur...

Digital Nerve Injury

Checkpoint Surgical Inc.

NCT06637735 N/A

The Effect of Education on Pregnant Women Perception of Traumatic Childbirth

Turkey (Türkiye)

Sakarya University

NCT06689176 N/A

Chlorhexidine Antiseptic Irrigation of the Bowel Segment During Radical Cystecto...

Icahn School of Medicine at Mo

NCT06693817 N/A

Advanced Wireless Sensors for Neonatal Care in the Delivery Room

Sudden Unexplained Infant Death

Brazil, Canada, Italy

Guilherme Sant'Anna, MD

NCT07315932 N/A

Perception of Hormonal Replacement Therapy Among Patients Aged 11 to 17 Years

Female Hypogonadism

University Hospital, Strasbour

NCT07219498 N/A

Effects of a 5-Week Probiotic Supplementation Intervention on Markers of Delayed...

Exercise Induced Muscle Damage

University of Minnesota

NCT07539363 N/A

Effect of "RECAST-H" (REverse CAses STudies Based on Heutagogy Approach) on Prof...

Nurses Behaviors

Turkey (Türkiye)

Hacettepe University

NCT06492187 N/A

Triage Survey for Infectious Disease Eligibility

Vaccination; Infection

Brooklyn Clinical Research

NCT06838793 N/A

ITPB 1 vs 3 in VATS

Musculoskeletal Diseases or Conditions

Chinese University of Hong Kon

NCT06764693 N/A

An Ex-US Study to Assess Treatment Persistence With Risankizumab in Adult Partic...

Psoriatic Arthritis

Argentina, Austria, Belgium

NCT06324916 N/A

Donor Site Morbidity After Free Vascularized Fibular Graft

Assiut University

NCT07349316 N/A

The Effects of Weight and Nutrition Education on Weight Control Beliefs, Body Im...

Dietary Restraint

St. Joseph's Healthcare Hamilt

NCT06825104 N/A

Long-Term Evaluation of TAILORED Vs Anatomical Ablation Strategy for Persistent ...

Atrial Fibrillation

France, Germany

NCT07059884 N/A

Distance-Based Exercise to Preserve Function and Prevent Disability

Localized Malignant Solid Neoplasm

Alliance for Clinical Trials i

NCT07770438 N/A

Evaluating the Effects of Reproductive Health Training on Provider Behavior - Ai...

Sexual and Reproductive Health

University of Minnesota

NCT05239338 N/A

Preserving Fertility After Colorectal Cancer Study

Colorectal Cancer

Andreana Holowatyj, PhD, MSCI

NCT06443138 N/A

Preparation for Medical and Surgical Procedures in Oncogeriatry.

Geriatric Oncology

Centre Hospitalier Universitai

NCT03993158 N/A

Newborns From Patients Treated With ART (Assisted Reproductive Technology)

The First Affiliated Hospital

NCT06720558 N/A

Effects of a Placebo Probiotic on Gut Health and General Well-being in Individua...

Catholic University of the Sac

NCT07806838 N/A

Effects of Dietary Supplements on Muscle Mass and Function While Using GLP-1 Med...

Obesity & Overweight

University of California, Los

NCT05974358 N/A

KONO-S Anastomosis Compared to Conventional Ileocolonic Anastomosis to Reduce Re...

Centre Hospitalier Universitai

NCT05767658 N/A

Support Via Online Social Networks to Promote Safe Infant Care Practices

University of Virginia

NCT05946278 N/A

Genetic Regulators of Bone Health That Are Unique to Vertebral Bone

Age-Related Osteoporosis

University of Colorado, Denver

NCT07560085 N/A

Catheter-Oriented Unloading and Recovery With a Left Ventricular Assist Gear: Ef...

Cardiogenic Shock

ForQaly Medical (Shanghai) Co.

NCT05355415 N/A

Adaptive Optics Imaging of Outer Retinal Diseases

Retinal Degeneration

Food and Drug Administration (

Page 5 of 276 — 6,885 trials total

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ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer · Last Reviewed: September 2026 · Data Methodology