Could a plant extract ease ADHD in adults? new trial results are in
NCT ID NCT05202327
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.
Disclaimer
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This is a summary of
the original study
.
Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.
This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.
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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
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Locations
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Cheng Hsin General Hospital
Taipei, 112, Taiwan
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Kaohsiung Chang Gung Memorial Hospital
Kaohsiung City, 83301, Taiwan
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Linkou chang Gung Memorial Hospital
Taoyuan, 33425, Taiwan
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National Taiwan University Hospital
Taipei, 10002, Taiwan
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Taipei veterans General Hospital
Taipei, 112, Taiwan
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University of California, San Francisco
San Francisco, California, 94143, United States