Effects of L-Phenylalanine on PKU Carriers and Non-Carriers

Phe for Me? A Precision Nutrition Clinical Trial of Metabolic, Cardiovascular, and Neurocognitive Responses to Phenylalanine Among Carriers and Non-carriers of PKU

Not applicable Interventional University of Guelph · NCT06119048

This study is testing how L-Phenylalanine affects mental health and thinking skills in people who carry the gene for PKU compared to those who don't.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment50 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity of Guelph Academic / other
Locations2 sites (Guelph, Ontario and 1 other locations)
Trial IDNCT06119048 on ClinicalTrials.gov

What this trial studies

This clinical intervention examines the effects of L-Phenylalanine on individuals who are carriers of phenylketonuria (PKU) compared to non-carriers. Participants will undergo baseline assessments of mental health and cognition, followed by fasting blood and saliva samples to evaluate the functioning of the PAH pathway. The study aims to understand how L-Phe affects mental health and cognitive function in these groups. The research is conducted at the Human Nutraceutical Research Unit at the University of Guelph.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18 and older who are either carriers or non-carriers of PKU and are comfortable fasting for the study.

Not a fit: Patients diagnosed with PKU or severe neurodegenerative conditions, as well as those with certain health issues or contraindications, may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into the mental health effects of L-Phenylalanine in PKU carriers, potentially leading to improved management strategies.

How similar studies have performed: While there may be limited studies directly examining L-Phe's effects on mental health in PKU carriers, related research on dietary impacts in genetic disorders has shown promise.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Carrier or non-carrier of PKU
* At least 18 Years of age
* Comfortable fasting the morning of the study (no food or drink other than water)

Exclusion Criteria:

* Diagnosed with: PKU, severe neurodegenerative conditions affecting cognition (e.g. Alzheimer's, Parkinson's, dementia), melanoma, hypertension, liver disease and/or kidney disease
* Diagnosed with hypertension or hypotension
* Taking a monoamine oxidase inhibitor anti-depressant
* Pregnant or breastfeeding
* Orange/citrus allergy or intolerance
* Body weight 150 kg or greater
* History of fainting during blood sampling

Where this trial is running

Guelph, Ontario and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Autosomal Recessive Disorder
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.