From the Guidelines
Normal estradiol levels for women taking combined birth control pills typically range from 10-50 pg/mL (or 37-184 pmol/L), which is lower than natural cycle levels. This reduction occurs because the synthetic hormones in the pill suppress the body's natural production of estradiol by inhibiting the hypothalamic-pituitary-ovarian axis. The exact level can vary depending on the specific formulation and dosage of the pill, with higher-dose pills potentially allowing slightly higher estradiol levels than lower-dose formulations, as seen in studies such as 1 and 1.
Key Considerations
- These suppressed levels are normal and expected while on hormonal contraception and don't indicate any health concerns.
- When interpreting estradiol test results while on birth control, healthcare providers consider these lower baseline values rather than comparing to normal ranges for women not taking hormonal contraception.
- The dosage of ethinyl estradiol in combined oral contraceptive pills (COCs) can vary from 10 to 50 μg, with "low-dose" pills (35 μg or less) being first-line options for adolescents, as noted in 1 and 1.
- If you're concerned about your specific estradiol levels while on birth control, it's best to discuss the results with your healthcare provider who can interpret them in the context of your particular pill formulation and overall health status.
Clinical Implications
- The use of COCs can have various effects on the body, including an increased risk of blood clots, as mentioned in 1 and 1.
- However, the benefits of COCs, such as reducing the risk of endometrial and ovarian cancers, as seen in 1, often outweigh the risks for many women.
- Healthcare providers should consider these factors when prescribing COCs and monitoring patients' health while on hormonal contraception.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Estradiol Levels and Combined Birth Control Pills
- The normal Estradiol level when taking the combined birth control pill is not explicitly stated in the provided studies, as they focus on the pharmacokinetics, pharmacodynamics, and risk assessment of combined oral contraceptives (COCs) rather than specific Estradiol levels 2, 3.
- However, it is mentioned that new progestin formulations combined with lower doses of ethinyl estradiol (EE) have reduced the incidence of venous thromboembolism and other negative outcomes of COC treatment 2.
- The use of endogenous 17β-estradiol (E₂) instead of EE in COCs has been explored, with E₂-based formulations showing similar efficacy and cycle control as EE-based COCs 2, 3.
- Studies have investigated the effects of combined oral contraceptives on various health parameters, such as endothelium-dependent vasodilation, serum biomarkers, and resting blood pressures, but do not provide information on normal Estradiol levels 4, 5, 6.
Effects of Combined Oral Contraceptives on Health Parameters
- A study found that a combined oral contraceptive containing 30 mcg ethinyl estradiol and 3.0 mg drospirenone does not impair endothelium-dependent vasodilation 5.
- Another study investigated the effects of a combination of ethinyl estradiol plus a progestogen with antimineralocorticoid properties, drospirenone, on body weight, blood pressure, and other health parameters, but did not report on Estradiol levels 6.
- The development of new combined oral contraceptives with lower doses of estrogen and improved progestin formulations aims to reduce side effects and improve cycle control, but the specific impact on Estradiol levels is not addressed in the provided studies 2, 3, 4.