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Transgender Estradiol

Sublingual Estradiol Versus Oral Estradiol in Transgender Women

Status
Completed
Phases
Early Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04036500
Enrollment
11
Registered
2019-07-29
Start date
2019-09-23
Completion date
2020-07-13
Last updated
2025-04-11

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

Conditions

Transgender Persons

Brief summary

Blogs, word-of-mouth, and small studies from the 1990s in the premature ovarian insufficiency and menopause populations have suggested sublingual or transdermal estradiol may be safer and/or more effective than an oral formulation. Sublingual administration entails holding the estrogen tablet under the tongue and allowing it to dissolve, where its absorption is enhanced by the rich vascularization under the tongue. According to Price et al., sublingual administration results in rapid absorption with significantly higher estradiol levels than does comparable oral dosing. This is likely because sublingual administration will bypass metabolism by the intestines and liver. The transdermal route, which also bypasses first-pass metabolism, is not associated with an increased venous thromboembolic risk nor a significant increase in plasma triglycerides or HDL-cholesterol levels. As such, transdermal estrogen is often preferred over oral formulations, although it is relatively expensive and not accessible to many transgender women. Conversely, sublingual administration of estrogen tablets is widely available and could be a cost-effective alternative to transdermal estrogen. However, there are no well-conducted studies that have evaluated the safety and efficacy of sublingual estrogen therapy in the transgender population. This pilot study will elucidate how estrogen levels in the blood change following sublingual versus oral administration of estradiol in transgender women. This data may be used later to design larger studies on safety and efficacy. Additionally, analyzing a dosage method that patients themselves have tried independently and found effective is also important. This approach incorporates intelligence from the transgender community into our research, creating new knowledge that is supported by data but is founded in existing community insights. Thus, the outcomes of this research have the potential to integrate patient input while also aiding in the development of safety recommendations, with the goal of better caring for our transgender patients. Primary aim. To establish the pharmacokinetics of sublingual estradiol versus oral estradiol in transgender women.

Detailed description

Patient will plan on being in the Adult Translational Research Unit (A-TRU) for 8 hours. They will be assigned to a suite. They will get 7 blood draws at hours 0,1,2,3,4,6,8 and vitals at the beginning of the visit. Vitals will include height, weight, blood pressure, respiration rate, and pulse. Subject is able to eat while in the A-TRU. Day 1 patient will take estradiol 1 mg ORALLY after time 0 blood draw. The medication will be given by registered nurse. A wash-out period of at least one week will allow for complete clearance of the exogenous oral estradiol before testing the pharmacokinetics of sublingual estradiol on the same ten patients in the same manner. Subject cannot take any hormone replacement therapy between their research appointments. On day 2, subject will take estradiol 1 mg SUBLINGUALLY after time 0 blood draw, supervised by a research team member to ensure proper dissolution. Blood will be drawn at hours 0,1,2,3,4,6,8 as on day 1.

Interventions

DRUGEstradiol

Patients will be given estradiol: 1 mg oral and 1 mg sublingual.

Sponsors

Medical College of Wisconsin
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Transgender male-to-female * Naive to hormone therapy * English speaker * 18 years of age or older

Exclusion criteria

* History of hormone replacement therapy * Orchiectomy * Needle phobia * Serious bleeding condition * Active deep vein thrombosis, pulmonary embolism or history of these conditions * Active or recent (e.g., within the past year) arterial thromboembolic disease (e.g., stroke, myocardial infarction) * Liver dysfunction or disease * History of breast cancer * Known sensitivity or allergy to any components of the medications used * Taking potent CYP3A4 inhibitors or inducers, as determined by team pharmacist * Taking a medication that may cause additional physical or mental harm if stopped

Design outcomes

Primary

MeasureTime frameDescription
Maximum Serum Concentration of Estradiol8 hours
Area Under the Serum Concentration Versus Time Curve8 hoursMean for Area Under the Curve(AUC) for sublingual estradiol.
Oral Clearance of Estradiol8 hours

Secondary

MeasureTime frameDescription
Ratio of Estrone to Estradiol8 hoursDescriptive statistics, such as mean for ratio of estrone to estradiol

Countries

United States

Participant flow

Recruitment details

Subjects were recruited by flyers in clinic waiting room and in clinic physician referrals. Subjects were initially screened over the phone with the screening criteria (n=17). There were 11 eligible subjects. One subject signed a consent form, but was withdrawn prior to initiation of the study.

Pre-assignment details

After the screening visit in which the pharmacist determined if there was metabolism alternating drugs being taken 10 patients were enrolled.

Participants by arm

ArmCount
Estradiol Oral
Subjects will take estradiol 1 mg orally after time 0 blood draw. They will get 7 blood draws at hours 0,1,2,3,4,6,8. A wash-out period of at least one week will allow for complete clearance of the exogenous oral estradiol before testing the pharmacokinetics of sublingual estradiol on the same ten patients in the same manner. On day 2 of study, subject will take estradiol 1 mg sublingually after time 0 blood draw, supervised by a research team member to ensure proper dissolution. Blood will be drawn at hours 0,1,2,3,4,6,8 as on day 1 of study.
10
Total10

Baseline characteristics

CharacteristicEstradiol Oral
Age, Categorical
<=18 years
0 Participants
Age, Categorical
>=65 years
0 Participants
Age, Categorical
Between 18 and 65 years
10 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
1 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
9 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
Race (NIH/OMB)
Asian
0 Participants
Race (NIH/OMB)
Black or African American
1 Participants
Race (NIH/OMB)
More than one race
0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
Race (NIH/OMB)
White
9 Participants
Sex/Gender, Customized
Transgender Woman
10 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 100 / 10
other
Total, other adverse events
0 / 100 / 10
serious
Total, serious adverse events
0 / 100 / 10

Outcome results

Primary

Area Under the Serum Concentration Versus Time Curve

Mean for Area Under the Curve(AUC) for sublingual estradiol.

Time frame: 8 hours

ArmMeasureValue (MEAN)Dispersion
Estradiol 1 mg Oral First, Then Estradiol 1 mg SublingualArea Under the Serum Concentration Versus Time Curve74.0883 mg*h/LStandard Deviation 17.18
Primary

Maximum Serum Concentration of Estradiol

Time frame: 8 hours

ArmMeasureGroupValue (MEAN)Dispersion
Estradiol 1 mg Oral First, Then Estradiol 1 mg SublingualMaximum Serum Concentration of EstradiolMax sublingual serum estradiol144 pg/mLStandard Deviation 90
Estradiol 1 mg Oral First, Then Estradiol 1 mg SublingualMaximum Serum Concentration of EstradiolMax oral serum estradiol35 pg/mLStandard Deviation 8
Primary

Oral Clearance of Estradiol

Time frame: 8 hours

ArmMeasureValue (MEAN)
Estradiol 1 mg Oral First, Then Estradiol 1 mg SublingualOral Clearance of EstradiolNA mL/hour
Secondary

Ratio of Estrone to Estradiol

Descriptive statistics, such as mean for ratio of estrone to estradiol

Time frame: 8 hours

ArmMeasureGroupValue (MEAN)Dispersion
Estradiol 1 mg Oral First, Then Estradiol 1 mg SublingualRatio of Estrone to Estradiolestradiol to estrone ratio, sublingual1.1 RatioStandard Deviation 1
Estradiol 1 mg Oral First, Then Estradiol 1 mg SublingualRatio of Estrone to Estradiolestradiol to estrone ratio, oral0.7 RatioStandard Deviation 0.4

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