The monthly bleeding experienced on most combined birth control is not a true physiological period but a withdrawal bleed caused by the drop in hormones during the placebo week. Stopping or skipping this monthly cycle is known as induced or intentional amenorrhea. The decision to suppress menstruation can be for convenience or, more often, for medical reasons, and understanding the mechanisms and implications is important for anyone considering this approach.
Methods of Menstrual Suppression
The cessation of monthly bleeding is achieved by maintaining a continuous, stable level of synthetic hormones that prevent the uterine lining from building up significantly. Combined hormonal contraceptives (CHCs), which contain both estrogen and progestin, can be taken continuously without the typical seven-day break, eliminating the hormone withdrawal that triggers the bleed. This continuous input of hormones suppresses the release of FSH and LH, preventing ovarian follicle development and ovulation.
Progestin-only methods, such as the injection, implant, or hormonal intrauterine device (IUD), work primarily by thickening cervical mucus and thinning the endometrium, the lining of the uterus. This thinning, known as endometrial atrophy, means there is little or no tissue to shed each month, leading to a substantial reduction in bleeding or complete amenorrhea. The hormonal IUD, in particular, delivers the progestin levonorgestrel directly to the uterus, resulting in amenorrhea for up to 60% of users after five years. Extended-cycle pills and continuous regimens are ways of administering CHCs to achieve this steady-state hormonal effect.
Addressing Common Health Misconceptions
A frequent concern is that stopping the monthly bleed is unnatural and could lead to a harmful buildup of blood or toxins in the body. This fear is a misconception rooted in the misunderstanding of what the bleeding on hormonal birth control represents. The monthly bleed experienced while using a typical 28-day pill pack is not a necessary biological “cleansing” process, but rather a predictable, non-physiological withdrawal bleed.
A true menstrual period occurs when the body’s natural levels of progesterone and estrogen drop, signaling the shedding of a thick, nutrient-rich endometrial lining prepared for a potential pregnancy. Hormonal contraceptives prevent the endometrial lining from reaching that stage of significant buildup. Since the lining remains thin and atrophic due to the continuous hormone exposure, there is nothing substantial for the body to shed, meaning no blood or toxins are being retained. Manipulating the menstrual cycle in this way does not carry the health risk of endometrial overgrowth that occurs without hormonal support.
Therapeutic Uses for Menstrual Control
For many individuals, menstrual suppression is a medical strategy to manage specific health conditions, not just a matter of convenience. Conditions characterized by excessive blood loss, such as heavy menstrual bleeding (menorrhagia), can lead to iron-deficiency anemia, which is effectively treated by eliminating the monthly blood loss. Similarly, the pain associated with severe dysmenorrhea, or painful periods, and conditions like endometriosis often improve significantly with continuous hormonal therapy.
Suppression is also beneficial for managing conditions where symptoms worsen cyclically due to natural hormone fluctuations. Conditions that can be stabilized when the hormonal cycle is flattened and the monthly hormone withdrawal is avoided include migraine without aura, epilepsy, and premenstrual dysphoric disorder (PMDD). Eliminating the period removes the trigger of these cyclical symptoms, offering a predictable improvement in quality of life.
Physical Side Effects and Fertility Implications
While menstrual suppression is generally safe, it can be associated with certain physical side effects, particularly during the initial adjustment period. The most common side effect is unscheduled bleeding, often called breakthrough bleeding or spotting, which tends to decrease in frequency and duration over the first few months of continuous use. Other common, non-serious side effects can include temporary breast tenderness, nausea, or mood changes related to the hormonal input.
A serious but rare risk is associated with combined hormonal contraceptives (those containing estrogen), which can slightly increase the risk of venous thromboembolism (VTE), or blood clots. The absolute risk remains very low, estimated at around 7 to 10 VTE events per 10,000 women per year for users, compared to 1 to 5 per 10,000 for non-users, but this is a factor considered during prescription. Progestin-only methods, which are often used for suppression, do not carry this increased risk of VTE.
Research consistently shows that birth control use does not cause long-term infertility. Fertility generally returns to the individual’s baseline level shortly after stopping the method. While combined hormonal methods and implants typically allow ovulation to resume within one to three months, the injectable form of progestin can cause a longer delay, sometimes taking 10 to 18 months for fertility to return.