Den här översättningen är inte klar ännu. Den här sidan är just nu på engelska.

Gå till den engelska sidan

Could a plant extract ease ADHD in adults? new trial results are in

NCT ID NCT05202327

What the study statuses mean

This study's is highlighted.

Recruitment status, easiest to join first

Recruiting now
This trial is taking on new participants right now.
Not yet recruiting
Registered, but not yet taking participants.
By invitation only
Not open to general applications. Only people the study team invites can take part.
Paused
Paused for now. It may or may not start again.
Ongoing
Running, but no longer taking on new participants.
Completed This study
The trial has finished. Results may not be published yet.
Stopped early
Stopped early, before it reached the end. That can be for many reasons, including safety.
Cancelled
Cancelled before anyone took part.

Expanded access (not trials)

Expanded access
Not a trial. This treatment can be requested outside a study, case by case, for people who qualify.
Expanded access (paused)
Not a trial. The treatment can normally be requested outside a study, but is unavailable right now.
Expanded access (ended)
Not a trial. The treatment could once be requested outside a study, but no longer can.
Approved
The treatment has been approved, so it is available normally rather than through this programme.

When the status isn't known

Details not published
The full record has not been published yet, so there is little to show here.
Status unknown
This status has not been confirmed recently, so it may be out of date.

First seen Jun 25, 2026 · Last updated Jun 27, 2026 · Updated 1 time

Summary

This Phase II trial tested PDC-1421, a capsule made from a plant extract, in 99 adults with ADHD. Participants were randomly assigned to receive the capsule or a placebo for up to 8 weeks. The goal was to see if the treatment could reduce ADHD symptoms and to check its safety.

What this could mean

Our plain-language read of the trial. This is informational only, not medical advice or a prediction.

Active substance
PDC-1421 (extract of Radix Polygalae, a plant-based capsule)
What this could lead to
If it works, this could point toward a new plant-based option to help ease ADHD symptoms in adults.
What could go wrong
This is an early Phase II trial with only 99 people, so results may not apply widely. The treatment may not work better than placebo, and side effects are still being studied.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Study facts

What this study's own registry entry says, in plain language.

Phase

Phase 2

Tests whether the treatment actually works, and watches for side effects, in a larger group.

Participants

99 people

The number who actually took part.

Started

Apr 2022

Finished

Apr 2024

Lead sponsor

A company

The lead sponsor is a pharmaceutical, biotech, or medical-device company.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Ages

18 to 70 years

Sex

Anyone

Healthy volunteers

Not accepted

This study is not open to healthy volunteers. The entry requirements below say who it is open to.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Aged 18-70 years 2. Female subjects of child-bearing potential must test negative to pregnancy and use appropriate birth control method from the beginning of study to the 15 days later after ending of study 3. Subjects must be able to understand and willing to sign informed consent 4. Able to discontinue the use of any psychotropic medications for the treatment of ADHD symptoms at screening 5. Meet strict operational criteria for adult ADHD according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) 6. A total score of 28 or higher of ADHD Rating Scale-Investigator Rated (ADHD-RS-IV) at screening 7. Have a moderate or severe symptom of ADHD with score of 4 or higher in Clinical Global Impression- Severity (CGI-S) at screening Exclusion Criteria: 1. Have any clinically significant concurrent medical condition (endocrine, renal, respiratory, cardiovascular, hematological, immunological, cerebrovascular, neurological, anorexia, obesity or malignancy) that has become unstable and may interfere with the interpretation of safety and efficacy evaluations 2. Have any clinically significant abnormal laboratory, vital sign, physical examination, or electrocardiogram (ECG) findings at screening that, in the opinion of the investigator, may interfere with the interpretation of safety or efficacy evaluations 3. Have known serological evidence of human immunodeficiency virus (HIV) antibody 4. Are pregnant as confirmed by a positive pregnancy test at screening 5. Have QTc values \>450 msec at screening using Fridericia's QTc formula 6. Have current of bipolar and psychotic disorders 7. Have a current major depression disorder, obsessive-compulsive disorder, post-traumatic stress disorder, generalized anxiety disorder, panic disorder and eating disorder (also if treated but not currently symptomatic) NOTE: Comorbid diagnoses identified during screening and baseline are acceptable provided that ADHD is the primary diagnosis and the comorbid diagnoses will not confound study data or impair subject's ability to participate (per the Investigator's judgement and documented in source note). 8. Have any history of a significant suicide attempt, or possess a current risk of attempting suicide, in the investigator's opinion, based on clinical interview and responses provided on the Columbia-Suicide Severity Rating Scale (C-SSRS). 9. Have a history of jailing or imprisonment in the past 6 months due to worsening of symptoms of ADHD

Get updates

Get notified about this study

Sign up to get updates when this study changes or when new studies for Attention deficit hyperactivity disorder (ADHD) are added.

Vår säkerhetsrekommendation!

Genom att skicka in godkänner du våra Användarvillkor

Conditions

The condition(s) this trial relates to.

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Cheng Hsin General Hospital

    Taipei, 112, Taiwan

  • Kaohsiung Chang Gung Memorial Hospital

    Kaohsiung City, 83301, Taiwan

  • Linkou chang Gung Memorial Hospital

    Taoyuan, 33425, Taiwan

  • National Taiwan University Hospital

    Taipei, 10002, Taiwan

  • Taipei veterans General Hospital

    Taipei, 112, Taiwan

  • University of California, San Francisco

    San Francisco, California, 94143, United States

More trials for these conditions

Other studies related to the condition(s) this trial covers.