Estradiol Test, Ultrasensitive
This page explains the estradiol test, ultrasensitive, what it measures, and how to arrange it. An estradiol test, ultrasensitive, measures very low levels of estradiol, a form of estrogen, in the blood. It is ordered when standard estradiol tests are not sensitive enough, often to monitor hormone therapy or evaluate certain hormone-related conditions.
- Sample type
- blood
- Category
- Hormone
- Turnaround
- 1-3 business days
- Price
- $198
- Referral
- Not required
An estradiol test, ultrasensitive, measures very low levels of estradiol, a form of estrogen, in the blood. It is ordered when standard estradiol tests are not sensitive enough, often to monitor hormone therapy or evaluate certain hormone-related conditions.
What it measures
- Estradiol — The main estrogen measured; ultrasensitive methods detect very small amounts.
- Total estradiol — The overall amount of estradiol in the blood sample.
- Free estradiol (calculated) — The portion not bound to proteins, estimated from other results.
- Sex hormone binding globulin (SHBG) — A protein that binds estradiol; sometimes measured to interpret free levels.
- Testosterone (total) — Often checked alongside estradiol when hormone balance is evaluated.
Who it is for
A clinician may order this test for people receiving estrogen therapy, those with symptoms of hormone imbalance, or when monitoring certain treatments. It is also used in some fertility and gender-affirming care settings.
Preparation
No fasting is usually required. Tell your clinician about all medications, including estrogen products, as timing and dose can affect results.
Results and what they mean
Results are reported as a number with a reference range, which varies by age, sex, and lab method. A clinician interprets the result in the context of your symptoms, medications, and other tests. This is general information, not medical advice; discuss your results with a qualified healthcare professional.
How to order this test
- Choose the test and place a confidential order online.
- Select a certified collection site and pick a time that suits you.
- Have your specimen collected — most draws take only a few minutes.
- Review results in a secure portal, typically within 1–3 days.
Preparation, hours, and pricing vary by site; confirm details directly with the lab before your visit.
Availability by state
Direct-access online ordering for the estradiol test, ultrasensitive is available in most states. It is currently unavailable in 6 states:
Everywhere else you can order confidentially and collect your sample at a certified site. Browse by state →
Frequently asked questions
Do I need to fast for this test?
No, fasting is not typically required. Follow any instructions from your clinician.
How soon will I get results?
Most results are available within 1 to 3 business days, though this can vary by lab.
Can my medications affect the result?
Yes. Estrogen products, some fertility drugs, and other hormones can change estradiol levels. Tell your clinician what you take.
Is this test the same as a regular estradiol test?
It uses a more sensitive method to detect very low levels, which a standard test may miss.