An interventional study of Creatine Monohydrate and Maltodextrin Placebo in Cognitive Function Assessment and Mental Fatigue, sponsored by University of Northern Iowa. Completed at 1 site in United States. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-21.
Sponsored by University of Northern Iowa · Not applicable, Interventional, and Basic science
This study examined whether short-term creatine supplementation affects cognitive function in healthy young adults. Participants were randomly assigned to take either creatine monohydrate or a placebo for 10 days. Participants took 30 grams per day, divided into six 5-gram doses.
Before and after the supplementation period, participants completed cognitive tests designed to assess areas such as memory, attention, reaction time, and processing speed. Participants also completed a 30-minute mentally challenging Stroop task, and brain oxygenation was measured during cognitive testing using functional near-infrared spectroscopy (fNIRS).
The purpose of the study was to determine whether 10 days of high-dose creatine supplementation improves cognitive performance compared with placebo following a mentally challenging task.
159 studies on the registry are indexed under Mental Fatigue; 55 are open to participants now.
This study's enrollment of 24 is below the median of 45 across 129 interventional studies indexed under Mental Fatigue.
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Exclusion Criteria:
Participants received 30 g/day of creatine monohydrate for 10 consecutive days, divided into six 5-g doses consumed throughout the day and mixed with food or water.
Dietary Supplement: Creatine Monohydrate
Participants received 30 g/day of maltodextrin placebo for 10 consecutive days, divided into six 5-g doses consumed throughout the day and mixed with food or water.
Dietary Supplement: Maltodextrin Placebo
Participants consumed 30 g/day of creatine monohydrate (Creapure®; AlzChem Trostberg GmbH, Germany) for 10 consecutive days. The daily dose was divided into six 5-g doses consumed throughout the day and mixed with food or water. Each 5-g dose was provided in an individual bag.
Participants consumed 30 g/day of maltodextrin (Dry Maltodextrin; Cargill, Minnesota, USA) for 10 consecutive days. The daily dose was divided into six 5-g doses consumed throughout the day and mixed with food or water. The placebo was provided in individual bags and was similar to the creatine intervention in taste, color, texture, and appearance.
Cognitive Performance Standard Scores Assessed by Central Nervous System Vital Signs (CNSVS)
Cognitive performance was assessed using the Central Nervous System Vital Signs (CNSVS) computerized neurocognitive assessment battery. Standardized scores were obtained for cognitive domains including memory, psychomotor speed, reaction time, complex attention, cognitive flexibility, processing speed, executive function, simple attention, and motor speed. Standard scores are age-normalized with a mean of 100 and standard deviation of 15, with higher scores indicating better cognitive performance.
Time frame: Baseline and after 10 days of supplementation
Stroop Task Performance - Reaction Time
Mean reaction time during the Stroop cognitive task, measured in milliseconds. Reaction times will be averaged across the specified task blocks at each assessment time point.
Time frame: Baseline and after 10 days of supplementation
Stroop Test Performance - Accuracy
Accuracy during the Stroop cognitive task, expressed as the percentage of correctly completed trials at each assessment time point.
Time frame: Baseline and after 10 days of supplementation.
Concentration of Prefrontal Cortex Oxygenation Assessed by Functional Near-Infrared Spectroscopy
Concentration of prefrontal cortex oxygenation was assessed using functional near-infrared spectroscopy (fNIRS; OctaMon+). Cerebral hemodynamic responses during cognitive testing were quantified using changes in oxygenated hemoglobin (O2Hb), deoxygenated hemoglobin (HHb), total hemoglobin (THb), and hemoglobin difference (HbDiff).
Time frame: Baseline and after 10 days of supplementation
Subjective Mental Fatigue Assessed Using a Visual Analog Scale
Subjective mental fatigue was assessed using a visual analog scale (VAS) during each cognitive testing session. Ratings were obtained at five time points: before cognitive testing, midway through the 30-minute Stroop task, immediately following the Stroop task, midway through the CNS Vital Signs assessment, and following completion of the CNS Vital Signs assessment.
Time frame: During cognitive testing at baseline and after 10 days of supplementation
Subjective Energy Assessed Using a Visual Analog Scale
Subjective energy was assessed using a visual analog scale (VAS) during each cognitive testing session. Ratings were obtained at five time points: before cognitive testing, midway through the 30-minute Stroop task, immediately following the Stroop task, midway through the CNS Vital Signs assessment, and following completion of the CNS Vital Signs assessment.
Time frame: During cognitive testing at baseline and after 10 days of supplementation.
Plan to share: No
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Creatine monohydrate
University of Northern Iowa