Autosomal Recessive Disorder (Genetic Carriers of PKU)Phe for MeNCT06119048
Phe for Me? The Effects of L-Phe on PKU Carriers and Non-carriers
A study testing L-Phenylalanine in people with Autosomal Recessive Disorder (Genetic Carriers of PKU), run by University of Guelph at 1 site in Canada.
Trial summary
This is a clinical intervention study of PKU carriers (cases) and non-carriers (controls). Upon completing the informed consent process, participants will complete baseline measures of chronic mental health prior to the intervention (PHQ-9, GAD-7, BIS-11). Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Autosomal Recessive Disorder (Genetic Carriers of PKU)
- What is being tested?
- L-Phenylalanine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 56 participants
- Where
- 1 siteCanada
- Study dates
- 18 Jun 2024to 3 Oct 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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)
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Phe for Me? A Precision Nutrition Clinical Trial of Metabolic, Cardiovascular, and Neurocognitive Responses to Phenylalanine Among Carriers and Non-carriers of PKU
This is a clinical intervention study of PKU carriers (cases) and non-carriers (controls). Upon completing the informed consent process, participants will complete baseline measures of chronic mental health prior to the intervention (PHQ-9, GAD-7, BIS-11). Participants will attend the Human Nutraceutical Research Unit (HNRU) at the University of Guelph, fasted, and first undergo baseline measures of cognition and acute mental health (mood) and provide samples or saliva, urine and dried blood spots to evaluate phenylalanine (Phe), tyrosine (Tyr) and their metabolites (PAH pathway functioning) as well as for genetic testing of the PAH gene. Participants will also complete a brief questionnaire which will include age, sex, ethnicity, income, weight and height (measured using a stadiometer and calibrated weigh scale), and confirmation that participants arrived to the lab fasted (i.e. have only had water to drink and no other foods/ beverages prior to analyses). Blood pressure and heart rate will also be measured at baseline.
Following baseline tests, participants will consume a pure L-Phe supplement dosed at 100 mg/kg mixed with 125 mL of water and 125mL of orange juice. Blood pressure and heart rate will be repeated at 1-hour post-L-Phe consumption. Two-hours postprandial, participants will repeat the cognitive tests and acute mental health (mood) assessment, blood pressure and heart rate measurement and provide follow-up saliva, urine and dried blood spot samples. Participants will also be asked to report any side effects they experienced with the L-Phe consumption.
- Being tested
- L-Phenylalanine
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
L-PhenylalanineDietary supplement
100 mg/kg
| Study group | Role | What they receive |
|---|---|---|
| Genetic Carriers and Non-Carriers of PKU | Experimental | Not described Receives: Dietary Supplement: L-Phenylalanine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Stop Signal Reaction Time
Response Inhibition
Measured: Change from baseline to 2-hours post L-Phe supplementation
Secondary outcomes (10)
Working Memory
N-Back Test Outcome
Measured: Change from baseline to 2-hours post L-Phe supplementation
Individual Coefficient of Variance (Variability in Reaction Time)
Stop Signal Task Outcome
Measured: Change from baseline to 2-hours post L-Phe supplementation
Phenylalanine Levels
Blood, saliva and urine sample analyses
Measured: Change from baseline to 2-hours post L-Phe supplementation
Tyrosine Levels
Blood, saliva and urine sample analyses
Measured: Change from baseline to 2-hours post L-Phe supplementation
Phenylalanine Metabolites
e.g. phenylethylamine, tyramine, phenylpyruvate, others
Measured: Change from baseline to 2-hours post L-Phe supplementation
Tyrosine Metabolites
e.g. L-DOPA, dopamine, norepinephrine, epinephrine, p-hydroxyphenylpyruvate, homogentisic acid, fumarate, others
Measured: Change from baseline to 2-hours post L-Phe supplementation
Mood
Profile of Mood State (POMS) Outcome
Measured: Change from baseline to 2-hours post L-Phe supplementation
Blood Pressure
Systolic and Diastolic
Measured: Change from baseline to 1-hour and 2-hours post L-Phe supplementation
Heart rate
BPM
Measured: Change from baseline to 1-hour and 2-hours post L-Phe supplementation
Side Effects Following L-Phe Consumption
To be monitored throughout the visit to the research unit
Measured: 0-3 hours post L-Phe consumption
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Nov 2023
- Study start18 Jun 2024
- Primary completion3 Oct 2025
- Study completion3 Oct 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Autosomal Recessive Disorder (Genetic Carriers of PKU)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 56 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Guelph
- Sponsor type
- University, hospital or other
- Collaborators
- McMaster University, Laval University
- Responsible party
- Principal investigator, Justine Keathley, University of Guelph
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06119048
- Sponsor's protocol ID
- 23-03-017
- Acronym
- Phe for Me
- Status last verified
- Apr 2026
- First submitted
- 31 Oct 2023
- Last updated
- 4 May 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Khan SM, Fennell ML, Fallah M, Jordan H, Kroezen Z, Britz-McKibbin P, Millar PJ, Heister RR, Vohl MC, Keathley JR. Study protocol and pilot study results for a clinical intervention trial of PKU carriers and non-carriers: the Phe for Me trial. Orphanet J Rare Dis. 2026 Jan 19;21(1):18. doi: 10.1186/s13023-025-04131-2.
PubMed 41555437
Study at a glance
From the registry record, last updated by the sponsor on 4 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phe for Me? A Precision Nutrition Clinical Trial of Metabolic, Cardiovascular, and Neurocognitive Responses to Phenylalanine Among Carriers and Non-carriers of PKU
- ClinicalTrials.gov ID
- NCT06119048
- Acronym / sponsor ID
- Phe for Me / 23-03-017
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 56 participants (actual)
- Lead sponsor
- University of GuelphUniversity, hospital or other
- Collaborators
- McMaster University, Laval University
- Study start
- 18 Jun 2024 (actual)
- Primary completion
- 3 Oct 2025 (actual)
- Study completion
- 3 Oct 2025 (actual)
- First posted
- 7 Nov 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a clinical intervention study of PKU carriers (cases) and non-carriers (controls). Upon completing the informed consent process, participants will complete baseline measures of chronic mental health prior to the intervention (PHQ-9, GAD-7, BIS-11). Participants will attend the Human Nutraceutical Research Unit (HNRU) at the University of Guelph, fasted, and first undergo baseline measures of cognition and acute mental health (mood) and provide samples or saliva, urine and dried blood spots to evaluate phenylalanine (Phe), tyrosine (Tyr) and their metabolites (PAH pathway functioning) as well as for genetic testing of the PAH gene. Participants will also complete a brief questionnaire which will include age, sex, ethnicity, income, weight and height (measured using a stadiometer and calibrated weigh scale), and confirmation that participants arrived to the lab fasted (i.e. have only had water to drink and no other foods/ beverages prior to analyses). Blood pressure and heart rate will also be measured at baseline.
Following baseline tests, participants will consume a pure L-Phe supplement dosed at 100 mg/kg mixed with 125 mL of water and 125mL of orange juice. Blood pressure and heart rate will be repeated at 1-hour post-L-Phe consumption. Two-hours postprandial, participants will repeat the cognitive tests and acute mental health (mood) assessment, blood pressure and heart rate measurement and provide follow-up saliva, urine and dried blood spot samples. Participants will also be asked to report any side effects they experienced with the L-Phe consumption.
Study design
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Genetic Carriers and Non-Carriers of PKU | Experimental | Dietary Supplement: L-Phenylalanine |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- 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)
Key exclusion criteria (7 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| L-Phenylalanine100 mg/kg | Dietary supplement | Genetic Carriers and Non-Carriers of PKU |
Primary outcome
Stop Signal Reaction Time
Time frame: Change from baseline to 2-hours post L-Phe supplementation
Response Inhibition
10 secondary outcomes
Working Memory
Time frame: Change from baseline to 2-hours post L-Phe supplementation
Individual Coefficient of Variance (Variability in Reaction Time)
Time frame: Change from baseline to 2-hours post L-Phe supplementation
Phenylalanine Levels
Time frame: Change from baseline to 2-hours post L-Phe supplementation
Tyrosine Levels
Time frame: Change from baseline to 2-hours post L-Phe supplementation
Phenylalanine Metabolites
Time frame: Change from baseline to 2-hours post L-Phe supplementation
Tyrosine Metabolites
Time frame: Change from baseline to 2-hours post L-Phe supplementation
Mood
Time frame: Change from baseline to 2-hours post L-Phe supplementation
Blood Pressure
Time frame: Change from baseline to 1-hour and 2-hours post L-Phe supplementation
Heart rate
Time frame: Change from baseline to 1-hour and 2-hours post L-Phe supplementation
Side Effects Following L-Phe Consumption
Time frame: 0-3 hours post L-Phe consumption
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 May 2026.
- Derived from this study: PubMed 41555437Khan SM, Fennell ML, Fallah M, Jordan H, Kroezen Z, Britz-McKibbin P, Millar PJ, Heister RR, Vohl MC, Keathley JR. Study protocol and pilot study results for a clinical intervention trial of PKU carriers and non-carriers: the Phe for Me trial. Orphanet J Rare Dis. 2026 Jan 19;21(1):18. doi: 10.1186/s13023-025-04131-2.
- Individual participant dataSharing planned: No
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing L-Phenylalanine in people with Autosomal Recessive Disorder (Genetic Carriers of PKU), run by University of Guelph at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 4 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Stop Signal Reaction Time (time frame: Change from baseline to 2-hours post L-Phe supplementation). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06119048, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 May 2026.