Low Estrogen Incontraception

Combined oral contraceptives

Combined oral contraceptives mimic the effects of female hormones. Once ingested, the contraceptive inhibits the release of gonadotroline-releasing hormone (GnRH) by the hypothalamus, thereby inhibiting the release of hormones by the pituitary gland that stimulate ovulation. Oral contraceptives also affect the mucosa of the uterus and cause thickening of cervical mucus, making it impervious to sperm. If used consistently and correctly, oral contraceptives are an effective form of contraception.

Oral contraceptives can be initiated at any time in a woman’s life until menopause.

Oral contraceptives can be a combination of estrogen and a progestin or only a progestin.

Estrogendosage in oral contraceptive

Most combined oral contraceptives have 15 to 30 micrograms of etinilestradiol. This dose of etinilestradiol is considered low. The low dosage of etinilestradiol in oral contraceptives is generally the most indicated, as formulas with lower dosages have been shown to be equally effective and have fewer side effects, with the exception of a higher incidence of irregular bleeding during the first months of contraceptive use.

Oral contraceptives have some very important health benefits. Oral contraceptives decrease development of endometrial cancer and ovarian cancer by about 50% at least 20 years after discontinuation of their use. They also decrease the risk of developing benign ovarian tumors, abnormal vaginal bleeding, dysmenorrhea, osteoporosis, dysphoric premenstrual disorder, anemia, benign breast diseases, and functional ovarian cysts. Ectopic pregnancy and salpingitis, which impair fertility, occur less frequently in users of oral contraception.


Contraception in adolescence

Oral contraceptives, due to their high efficacy and safety, are considered as the method of choice for sexually active young women. In this age group are also valued the beneficial effects of these drugs on dysmenorrhea, menstrual irregularities, acne, hirsutism and prevention of pelvic inflammatory disease.

It has been shown that a teenage pregnancy alters the hormonal environment more and interferes more with growth than any oral contraceptive. If there is no associated medical problem, any healthy adolescent, after establishing the menstrual period, can take the pill, and this should be the lowest possible estrogen dosage, maintaining the necessary efficacy and safety.

What to do in case blood loss appears outside the days of pause?

During the first months of using the low-dose oestrogen pill, minor bleeding is often found outside of break days. These hemorrhages, usually of little intensity, are called “spotting” and usually disappear spontaneously. It just means that the organism is adapting. The effectiveness of the pill is maintained.

What are the contraindications to taking the pill and who cannot take it?

The pill can be taken by any woman of childbearing age, but there are some situations where it is advisable to use other methods of contraception. Therefore, before starting to take a contraceptive, it is advisable to consult a doctor.

Does the pill prevent any disease?

The use of the pill seems to have some health benefits, namely in reducing the occurrence of pelvic inflammatory disease, benign breast disease, anemia and endometrial and ovarian cancer.

Key ideas to retain on oral contraception

  • Most women of childbearing age can make oral and continuous contraception until menopause if they have no contraindications
  • All combined oral contraceptives (estrogen and progestin) are equally effective; low-dose formulations of oestrogen are preferred because they have fewer adverse effects
  • Oral contraceptives may have clinical indication in addition to contraception
  • The risk of using oral contraception has decreased in recent years as increasingly lower hormone doses are used
  • There is no evidence of an increased incidence of neoplasms in general in users of oral contraception
  • Pop (‘progestagen-only pill’) does not affect the quality or quantity of breast milk
  • Progesterone-only oral contraceptives may cause irregular bleeding and should be taken at the same time every day

More Information

You can find more information about contraception on this page.

Editorial Note: This page and all other contents present in
are prepared and reviewed by medical experts in Portugal.