Recruiting

Phenylalanine Requirement

Sponsor:

University of British Columbia

Code:

NCT07481201

Conditions

Menstrual Cycle

Eligibility Criteria

Sex: Female

Age: 20 - 35

Healthy Volunteers: Accepted

Interventions

Dietary Phenylalanine Intakes

Study Details

Brief 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. 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.

Conditions

Menstrual Cycle

Study ID

NCT07481201

Start date

May 1, 2026

Status verified date

May, 2026

Completion date

Dec 1, 2028

Anticipated

Primary completion date

Dec 1, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Female

Age: 20 - 35

Healthy Volunteers: Accepted

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.

Study Design

Enrollment

15 participants

Anticipated

Intervention Model

Single group

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Test Phenylalanine Intake

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.

Interventions

Dietary Phenylalanine Intakes

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.

Primary outcome measure

  • Carbon 13 Oxidation [ Time Frame: 8 hours ]

Central Contacts and Locations

Central contacts

Rajavel Elango

+4911 604-875-2000relango@bcchr.ubc.ca

Paloma DeLisle

778-683-2256paloma.delisle@bcchr.ca

Locations

BC Children's Hospital Research Institute

Recruiting

Vancouver, British Columbia, Canada, V5Z 4H4

Principal Investigator:

Rajavel Elango

More Information

Sponsor

University of British Columbia

Last update posted

May 7, 2026

Last verified

May, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of British Columbia on 2026-05-07.