Phenylalanine needs during the follicular and luteal menstrual phases
Official title: Phenylalanine Requirements in the Menstrual Phases
Run by University of British Columbia · NCT07481201 · Data updated 2026-11-12
We will test how much phenylalanine healthy menstruating women (ages 20–35) need during the follicular versus luteal phase of the menstrual cycle.
Quick facts
| Study type | Interventional |
|---|---|
| Ages | 20 Years to 35 Years |
| Sex | Women only |
| Enrollment | 15 (estimated) |
| Sponsor | University of British Columbia Academic / other |
| Locations | 1 site (Vancouver, British Columbia) |
| Status | Recruiting |
| Started | May 1, 2026 |
| Main results expected | December 1, 2028 |
| Study ends | December 1, 2028 |
| Registry record updated | May 7, 2026 |
| Trial ID | NCT07481201 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Ideal candidates are healthy menstruating females aged 20–35 with regular 21–35 day cycles, BMI 18–28 kg/m2, not pregnant or breastfeeding and not using hormonal contraceptives or hormone therapy.
✕Probably not a fit
People using hormonal birth control, hormone therapy, those who are pregnant, breastfeeding, recently postpartum, have irregular cycles, metabolic/endocrine disorders, or who follow non-traditional diets are unlikely to benefit or be eligible.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This interventional study uses the minimally invasive indicator amino acid oxidation method with safe stable isotopes, controlled diets, and simple breath collections to estimate dietary phenylalanine requirements in healthy menstruating females. Participants (minimum 15) will be studied in both the follicular and luteal phases and randomized to a range of phenylalanine intakes (2.5–22.5 mg/kg/day) across multiple study days. Each participant may complete up to seven test days per phase to gather requirement data at different intake levels, and the goal is to enroll at least seven participants per intake level. The protocol is modeled on previously published isotope-based work from the same lab that defined amino acid needs in pregnancy, lactation, and childhood.
Why it matters
Potential benefit: If successful, the results could support female-specific phenylalanine recommendations that account for menstrual-phase metabolic differences and improve dietary guidance.
How similar studies have gone: Related isotope-based indicator amino acid oxidation studies by the Elango Lab and others have been successfully used to determine amino acid requirements in pregnant, nonpregnant, lactating women and children.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * 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 Exclusion Criteria: * 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 * 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.
Where it's running
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BC Children's Hospital Research Institute
Vancouver, British Columbia, Canada Recruiting
Study contacts
- Study coordinator: Rajavel Elango
- Email: relango@bcchr.ubc.ca
- Phone: +4911 604-875-2000
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.