Related Experiment Video
Updated: Jun 5, 2026

An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
Published on: August 13, 2019
Oral contraceptive estrogen content and adverse effects
Abstract:
The 1985 Health and Welfare Canada Report on Oral Contraceptives recommended oral contraceptives (OCs) containing 30-35 mcg of estrogen rather than 50 mcg as the preferred dosage for contraception. Many family physicians may regard these guidelines as mandatory when prescribing OCs, because of a presumption that pills of 50-mcg estrogen content carry a higher risk of disease. In this article, the epidemiologic evidence pertaining to a dose-response relationship between the estrogen dose of oral contraceptives and disease is critically reviewed. The review indicates that there is no incontrovertible evidence to support such a relationship. Implications of the recommendations in the Report for physicians and patients are discussed.
More Related Videos
Related Concept Videos
Birth Control Methods
Menopause
Hormonal Control of the Ovarian Cycle
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
Hormonal Regulation of the Menstrual Cycle
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
Gonadal and Placental Hormones
In males, testosterone is the primary gonadal androgen. It plays a central role in the maturation of male reproductive organs — the penis and testes. Additionally, testosterone is instrumental in the development of secondary sexual characteristics — a deep voice as well as facial and pubic hair growth — and...
Oogenesis

