Menstrual CycleNCT07481201
Phenylalanine Requirements in the Menstrual Phases
A study testing Dietary Phenylalanine Intakes in people with Menstrual Cycle, run by University of British Columbia at 1 site in Canada.
Trial summary
Phenylalanine is an essential amino acid that must be obtained through food. Current adult phenylalanine recommendation is based on male-conducted studies and set the same for females. Read more about this study
- Who is it for?
- Ages 20 to 35 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Menstrual Cycle
- What is being tested?
- Dietary Phenylalanine Intakes
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteCanada
- Study dates
- 1 May 2026to 1 Dec 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 20 to 35 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- People with menstrual cycles
- Between the ages of 20 to 35y
- Regular menstrual cycle (21-35 day cycle) for the past 12 months
- Body mass index (BMI) of between 18 and 28 kg/m2
- Free from pre-existing health conditions
Who cannot join
- People who are currently using hormonal birth control or any contraceptive that would affect sex hormones
- People on hormone therapy
- People with an abnormal menstrual cycle history
- People with non-traditional dietary practices
- Recent weight loss/weight gain
- People with a history of endocrine disorders
Show all 11Show fewer
- People who are pregnant
- People who are breastfeeding
- People who have given birth in the last 18 months
- People who depend on medication that affects normal metabolism. Any medication that alters normal body metabolism would skew the results and compromise the validity of the data set.
- People with a metabolic, neurological, genetic, or immune disorder likely to affect nutritional requirements or overall body metabolism.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
BC Children's Hospital Research Institute
Vancouver, British Columbia, V5Z 4H4
Rajavel Elango
About this study
Phenylalanine is an essential amino acid that must be obtained through food. Current adult phenylalanine recommendation is based on male-conducted studies and set the same for females. These recommendations may not be appropriate for females, as they do not take into consideration the hormonal changes over the menstrual cycle. The menstrual cycle is a rhythmic hormonal process split into two phases, with hormones regulating metabolism differently. The aim of this study is to find phenylalanine requirement for healthy, menstruating females. An innovative, non-invasive technique utilizing pre-determined diets, safe stable isotopes, and a simple breath collection method will be used. Previous work done by Elango Lab investigators has applied this method to investigate other amino acids in pregnant, non-pregnant, and lactating females as well as in children.
Read the detailed description
The objective of this study is to assess phenylalanine requirements in healthy, menstruating females, between the ages 20-35, during the luteal and follicular phases using the minimally invasive indicator amino acid oxidation method.
In comprehending protein needs and achieving protein targets, it is imperative to establish individual amino acid requirements. This clinical study aims to determine the dietary phenylalanine requirement in females to help set nutrition guidelines for females that heavily consider the metabolic and hormonal effects of the differences between the menstrual cycle phases. The existing values, derived from guidelines designed for males, overlook the crucial impact of the menstrual cycle on energy and dietary intake. Relying on amino acid requirements derived from studies in males for females significantly heightens the risk of potential harm. It is crucial to identify the distinct amino acid requirements for females and grasp how these needs are affected by various phases of the menstrual cycle. A minimum of 15 healthy females (20-35 y) will be recruited and studied at two menstrual phases over a range of test phenylalanine intakes (2.5, 5, 7.5 10, 12.5 17.5, and 22.5 mg/kg/day). Subjects will be invited to participate in up to 7 study days/phase and randomized to a different intake at each study day. Participants' eligibility will be assessed during a pre-study day. The goal is to study a minimum of 7 participants at each intake, for a total of 49 study days in each stage.
- Conditions
- Menstrual Cycle
- Being tested
- Dietary Phenylalanine Intakes
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Dietary Phenylalanine IntakesOther
Participants consume 8 hourly meals that contain the assigned test phenylalanine intake. Each meal will provide one-twelfth of the participants' daily energy requirements as estimated by 1.5 x Resting Energy Expenditure (REE) and adequate protein at 1.0 g.kg.d, to maintain a metabolic steady state. The meals are in the form of a crystalline amino acid protein shake, and protein-free cookies.
| Study group | Role | What they receive |
|---|---|---|
| Test Phenylalanine Intake | Experimental | Randomly assigned one of 7 test phenylalanine intakes that range from deficient to excess (2.5mg/kg/d to 22.5mg/kg/d). Participants may complete up to 7 study days in each menstrual phase, at different randomly assigned intakes. Receives: Other: Dietary Phenylalanine Intakes |
What is being measured
The primary outcome is the main question the study is designed to answer.
Carbon 13 Oxidation
Urine and breath samples will be collected to measure the rate of L-[1-13C]-leucine oxidation.
Measured: 8 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Mar 2026
- Study start1 May 2026
- Primary completion1 Dec 2028 (estimated)
- Study completion1 Dec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Menstrual CycleStudies of the same condition, open and under way.
- More trials run by University of British ColumbiaThe sponsor's other registered studies.
- 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
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Single-day interventions; Repeated Measures Design
- Masking
- None (open label)
- Enrolment
- 15 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of British Columbia
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Rajavel Elango, PhD, University of British Columbia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07481201
- Sponsor's protocol ID
- H26-00530
- Status last verified
- May 2026
- First submitted
- 13 Mar 2026
- Last updated
- 7 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phenylalanine Requirements in the Menstrual Phases
- ClinicalTrials.gov ID
- NCT07481201
- Acronym / sponsor ID
- H26-00530
- Conditions
- Menstrual Cycle
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 15 participants (estimated)
- Lead sponsor
- University of British ColumbiaUniversity, hospital or other
- Study start
- 1 May 2026 (actual)
- Primary completion
- 1 Dec 2028 (estimated)
- Study completion
- 1 Dec 2028 (estimated)
- First posted
- 18 Mar 2026 (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.
Phenylalanine is an essential amino acid that must be obtained through food. Current adult phenylalanine recommendation is based on male-conducted studies and set the same for females. These recommendations may not be appropriate for females, as they do not take into consideration the hormonal changes over the menstrual cycle. The menstrual cycle is a rhythmic hormonal process split into two phases, with hormones regulating metabolism differently. The aim of this study is to find phenylalanine requirement for healthy, menstruating females. An innovative, non-invasive technique utilizing pre-determined diets, safe stable isotopes, and a simple breath collection method will be used. Previous work done by Elango Lab investigators has applied this method to investigate other amino acids in pregnant, non-pregnant, and lactating females as well as in children.
Detailed description
The objective of this study is to assess phenylalanine requirements in healthy, menstruating females, between the ages 20-35, during the luteal and follicular phases using the minimally invasive indicator amino acid oxidation method.
In comprehending protein needs and achieving protein targets, it is imperative to establish individual amino acid requirements. This clinical study aims to determine the dietary phenylalanine requirement in females to help set nutrition guidelines for females that heavily consider the metabolic and hormonal effects of the differences between the menstrual cycle phases. The existing values, derived from guidelines designed for males, overlook the crucial impact of the menstrual cycle on energy and dietary intake. Relying on amino acid requirements derived from studies in males for females significantly heightens the risk of potential harm. It is crucial to identify the distinct amino acid requirements for females and grasp how these needs are affected by various phases of the menstrual cycle. A minimum of 15 healthy females (20-35 y) will be recruited and studied at two menstrual phases over a range of test phenylalanine intakes (2.5, 5, 7.5 10, 12.5 17.5, and 22.5 mg/kg/day). Subjects will be invited to participate in up to 7 study days/phase and randomized to a different intake at each study day. Participants' eligibility will be assessed during a pre-study day. The goal is to study a minimum of 7 participants at each intake, for a total of 49 study days in each stage.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Single-day interventions; Repeated Measures Design
| Arm | Type | Receives |
|---|---|---|
| Test Phenylalanine Intake | Experimental | Other: Dietary Phenylalanine IntakesRandomly assigned one of 7 test phenylalanine intakes that range from deficient to excess (2.5mg/kg/d to 22.5mg/kg/d). Participants may complete up to 7 study days in each menstrual phase, at different randomly assigned intakes. |
Who may qualify
- Ages
- 20 to 35 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- People with menstrual cycles
- Between the ages of 20 to 35y
- Regular menstrual cycle (21-35 day cycle) for the past 12 months
- Body mass index (BMI) of between 18 and 28 kg/m2
- Free from pre-existing health conditions
Key exclusion criteria (11 listed)
- People who are currently using hormonal birth control or any contraceptive that would affect sex hormones
- People on hormone therapy
- People with an abnormal menstrual cycle history
- People with non-traditional dietary practices
- Recent weight loss/weight gain
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 |
|---|---|---|
| Dietary Phenylalanine IntakesParticipants consume 8 hourly meals that contain the assigned test phenylalanine intake. Each meal will provide one-twelfth of the participants' daily energy requirements as estimated by 1.5 x Resting Energy Expenditure (REE) and adequate protein at 1.0 g.kg.d, to maintain a metabolic steady state. The meals are in the form of a crystalline amino acid protein shake, and protein-free cookies. | Other | Test Phenylalanine Intake |
Primary outcome
Carbon 13 Oxidation
Time frame: 8 hours
Urine and breath samples will be collected to measure the rate of L-[1-13C]-leucine oxidation.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 May 2026.
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Dietary Phenylalanine Intakes in people with Menstrual Cycle, run by University of British Columbia 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 5 inclusion and 11 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: looking for participants now, as of the sponsor's last update on 7 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Rajavel Elango (+4911 604-875-2000, relango@bcchr.ubc.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Carbon 13 Oxidation (time frame: 8 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 7 May 2026; AzTrials last refreshed its copy on 6 Nov 2026.