Recruiting

Oral Contraceptive vs. Menstrual Cycle

Sponsor:

University of Toronto

Code:

NCT06124274

Conditions

Contraceptives, Oral

Sex Hormone

Eligibility Criteria

Sex: Female

Age: 18 - 35

Healthy Volunteers: Accepted

Interventions

Protein tracer drink

Study Details

Brief summary:

Despite comprising half the population, females are often left out of muscle research due to the impact of changing hormones during the menstrual cycle and when using oral contraceptives. This makes it hard to perform costly and invasive studies involving tracers to study muscle protein metabolism. Consequently, we lack a clear understanding of how these hormonal changes affect muscle growth.

There is a need for less invasive methods to study how sex hormones and oral contraceptives influence muscle protein metabolism. Ex vivo models, where serum from participants is applied to mouse muscle cell cultures, mimic the conditions of human muscle cells and can provide initial insights.

Conditions

Contraceptives, Oral

Sex Hormone

Study ID

NCT06124274

Start date

Aug 9, 2023

Status verified date

Nov, 2023

Completion date

Sep 1, 2024

Anticipated

Primary completion date

Sep 1, 2024

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Female

Age: 18 - 35

Healthy Volunteers: Accepted

Inclusion Criteria:

  • BMI between 18.5-29.9 kg/m2 (I.e., non-obese).
  • For OC users: on monophasic OCs for > 3 months prior to study enrollment
  • For non-OC users: regular menstrual cycles length (25-35 days) for at least 3 months prior to study and at least 6 months off of OCs.

Exclusion Criteria:

  • Chronic disease diagnosis (cardiovascular, thyroid, diabetes)
  • Current or recent remission of cancer
  • Regular use of NSAID (except low-dose aspirin), anticoagulants
  • Use of prescription drugs that would impact metabolism, e.g. Statins, Lithium, Attention-Deficit/Hyperactivity Disorder (ADHD) medication.
  • Insertion of intrauterine device (IUD) - exception: copper
  • Use of ergogenic aids such as creatine
  • Regular Tabacco use
  • Use of illicit drugs (growth hormones, testosterone)
  • For non-OC users: Use of oral contraceptives for > 6 months prior to study enrollment - to ensure return to regular menstrual cycle.

Study Design

Enrollment

10 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Other

Interventions and Outcome Measures

Arms

experimental: Mid-Follicular Phase

7-11 days after onset of menses.

experimental: Mid-Luteal Phase

5-9 days after ovulation (as confirmed with ovulation test kits).

experimental: Active pill phase

10-20 days after starting new pill cycle.

experimental: Withdrawal phase

48hrs after last pill (during placebo pill phase).

Interventions

Protein tracer drink

Subjects will be fed a mixed-macronutrient beverage at rest (0.75g/kg lean body mass of carbohydrates; 0.125g/kg lean body mass of protein). Amino acid composition of the protein will be modelled off the composition of egg. Leucine content will be enriched to 5% with \[13 Carbon(13C)\]-leucine.

Primary outcome measure

  • Protein Synthesis (Murine Cell-Based Experiments, ex-vivo experiments) [ Time Frame: 60 minutes ]

Central Contacts and Locations

Central contacts

Daniel R Moore, PhD

4169464088dr.moore@utoronto.ca

Ines Kortebi, PhD Student

ines.kortebi@mail.utoronto.ca

Locations

Goldring Centre for High Performance Sport at the University of Toronto

Recruiting

Toronto, Ontario, Canada, M5S2C9

Contacts

Daniel R Moore, PhD

416-946-4088dr.moore@utoronto.ca

Ines Kortebi, MSc

ines.kortebi@mail.utoronto.ca

More Information

Sponsor

University of Toronto

Last update posted

Nov 9, 2023

Last verified

Nov, 2023

Keywords

  • Oral Contraceptive Use
  • Menstrual Cycle Phases
  • Protein Metabolism
  • Ex Vivo Model
  • Breath Test

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 Toronto on 2023-11-09.