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Effect of Progesterone on Testosterone Concentrations and Breast Development in Transwomen

Effect of Progesterone on Testosterone Concentrations and Breast Development in Transwomen

Status
Terminated
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04534881
Enrollment
5
Registered
2020-09-01
Start date
2020-10-20
Completion date
2023-01-18
Last updated
2024-03-19

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Transgender Persons

Keywords

Testosterone, breast

Brief summary

* Purpose. The purpose of this research is study the effect of progesterone therapy on testosterone levels in transwomen who are currently on gender affirming treatment with estradiol. * Duration. It is expected that participation will last for 6 months (24 weeks). * Study Procedures. Participants will be asked to sign an informed consent, complete a medical history, have a physical exam conducted, have a fasting blood sample taken and asked to take a study drug once daily. * Risks. Some of the foreseeable risks or discomforts include temporary discomfort, bleeding, bruising and/or swelling in the arm from blood draw. There are no known direct risks with the use of Progesterone in Transwomen for gender affirming therapy. * Benefits. Some of the possible benefits that may be expected include increase in fat mass, increase in breast size/fullness, decrease in masculine hair patterns.

Detailed description

The number of individuals with gender incongruence who present to their physician for hormone therapy has increased manifold in the last decade. Testosterone therapy in transgender men (also known as female-to-male transgender or transmen) and estrogen therapy in transgender women (also known as male-to-female transgender or transwomen) respectively is the mainstay of hormone regimen.Transwomen, who are genetically men, receive estradiol replacement with the aim of suppressing serum testosterone and achieving serum estradiol concentrations that mimic the serum concentrations of biological women. This leads to an increase in fat mass, breast growth and decreases in lean mass and masculine pattern hair. However, the results of these changes are often less than satisfactory and additional therapy is required. Breast development is a major concern for transgender females. There is a great deal of variability among individuals, as evidenced during pubertal development.Transgender women do not achieve the same level of breast development as cisgender women do after puberty. Typically, transgender women plateau at Tanner stage III and half of the transgender women have a AAA cup size or less.Investigators plan to conduct a randomized, placebo controlled double blind study evaluating the effect of adding progesterone for 6 months to transwomen who are being treated with estradiol. The hypothesis is that progesterone will decrease serum testosterone concentrations as compared to placebo and increase breast size. Investigators will also assess its role in mood, sleep, scalp hair and androgenic hair growth.

Interventions

Subjects will be randomized to receive generic micronized progesterone 200 mg or placebo tablets, to be taken at bedtime daily.

DRUGPlacebo

Subjects will be randomized to receive generic micronized progesterone 200 mg or placebo tablets, to be taken at bedtime daily.

Sponsors

St. Louis University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Investigator)

Eligibility

Sex/Gender
MALE
Age
18 Years to 65 Years
Healthy volunteers
No

Inclusion criteria

* Transwomen, currently on treatment with estradiol therapy for at least 6 months (as their standard of care gender affirming therapy) * Has achieved serum estradiol \>100 pg/ml at least once, based on clinical labs in past.

Exclusion criteria

1. Treatment with progesterone in the last 2 months 2. HIV 3. Planning to go for breast enhancement or gender reassignment surgery in the next 6 months 4. Known history of peanut allergy (because the study drug contains peanut oil) 5. Active deep vein thrombosis, pulmonary embolism or history of these conditions 6. Active arterial thromboembolic disease or history of these conditions 7. Active cardiovascular disorders or history of these conditions (e.g. myocardial infarction, uncontrolled hypertension \>150/90 mmHg) 8. Known, suspected, or history of breast cancer 9. Known liver dysfunction or disease 10. Known or history of gallbladder disease. This does not apply to subjects who have undergone cholecystectomy 11. Known or history of hypertriglyceridemia (\>400 mg/dl)

Design outcomes

Primary

MeasureTime frameDescription
Efficacy: Testosterone24 weeksChange from baseline till 24 weeks in serum testosterone concentrations between progesterone and placebo groups. Calculated as testosterone levels at 24 weeks minus baseline

Countries

United States

Participant flow

Participants by arm

ArmCount
Progesterone
subjects on active drug (progesterone) Progesterone 200 MG: Subjects will be randomized to receive generic micronized progesterone 200 mg or placebo tablets, to be taken at bedtime daily.
3
Placebo
subjects on placebo Placebo: Subjects will be randomized to receive generic micronized progesterone 200 mg or placebo tablets, to be taken at bedtime daily.
2
Total5

Baseline characteristics

CharacteristicProgesteronePlaceboTotal
Age, Continuous31.7 years
STANDARD_DEVIATION 2.5
24.5 years
STANDARD_DEVIATION 0.7
28.8 years
STANDARD_DEVIATION 4.3
Ethnicity (NIH/OMB)
Hispanic or Latino
0 Participants0 Participants0 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
3 Participants2 Participants5 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Sex: Female, Male
Female
0 Participants0 Participants0 Participants
Sex: Female, Male
Male
3 Participants2 Participants5 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 30 / 2
other
Total, other adverse events
0 / 30 / 2
serious
Total, serious adverse events
0 / 30 / 2

Outcome results

Primary

Efficacy: Testosterone

Change from baseline till 24 weeks in serum testosterone concentrations between progesterone and placebo groups. Calculated as testosterone levels at 24 weeks minus baseline

Time frame: 24 weeks

ArmMeasureValue (MEAN)Dispersion
ProgesteroneEfficacy: Testosterone1.5 ng/dLStandard Deviation 4
PlaceboEfficacy: Testosterone-6.4 ng/dLStandard Deviation 0

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026