Extended cycle combined oral contraceptive pill
Extended cycle combined oral contraceptive pills are COCPs packaged to reduce or eliminate the withdrawal bleeding that occurs once every 28 days in traditionally packaged COCPs.  In the same way, other combined hormonal contraceptives (those containing both an estrogen and a progestogen) may be used in an extended or continuous cycle.  For example, the vaginal ring NuvaRing has been studied for extended cycle use and the monthly injection Lunelle may similarly eliminate bleeding.

# Usage
When a woman takes COCPs (combined oral contraceptive pills), the hormones in the pills prevent both ovulation and shedding of the endometrium (menstruation).  Traditionally, COCPs are packaged with 21 active (hormone-containing) pills, and 7 placebo pills.  During the week of placebo pills, withdrawal bleeding occurs, simulating an average 28-day menstrual cycle.  The placebo pills are not required for pregnancy protection, and with any monophasic COCP the placebo pills may be skipped (going straight to the next pack of active pills) to prevent the withdrawal bleeding.  Skipping the placebo pills with bi- and tri-phasic pills still protects from pregnancy, but due to the sudden change in hormone levels irregular spotting or flow is likely to occur.
Recently, several pharmaceutical companies have gained FDA approval to package COCPs for the intended use of reducing the frequency of or completely eliminating withdrawal bleeding.

# Clinical indications
Extended or continuous use of COCPs has been used for many years to treat endometriosis, dysmenorrhea, and menstruation-associated symptoms.  Some studies have suggested that women who experience premenstrual-type symptoms during the placebo (hormone-free) week of traditionally packaged COCPs may experience significantly fewer symptoms when placed on extended cycle COCP regimens.
More recently, personal preference to avoid menstruation has also become a common reason for use.  Personal preference is the most common reason extended cycle or continuous use COCPs are prescribed to adolescents.
Women's satisfaction with their contraceptive, compliance in taking the pills on time, and discontinuation rates are not significantly different between traditional and extended cycle regimens.

# Side effects
With all extended-cycle COCPs, breakthrough bleeding is the most common side effect, although it tends to decrease over time.  In a 12-month study of a continuous COCP regimen, 59% of women experienced no bleeding in months six through twelve, and 79% of women experienced no bleeding in month twelve.

## Ad campaign
One of the early extended-cycle COCPs, Seasonale, was marketed with the campaign, "Fewer periods.  More possibilities."  In December of 2004, Barr Pharmaceuticals was warned by the FDA concerning these television advertisements. As the warning stated, "By omitting and minimizing the risks associated with Seasonale, the TV ad misleadingly suggests that Seasonale is safer than has been demonstrated by substantial evidence or substantial clinical experience." Although clinical studies had proven Seasonale to be effective in preventing pregnancy, the FDA felt the commercial advertisements omitted the common side effects of irregular vaginal bleeding or spotting.

# Brands
Seasonale is produced by Duramed Pharmaceuticals, a subsidiary of Barr Pharmaceuticals.  Quasense is the generic version produced by Watson Pharmaceuticals.  Seasonale contains 30 micrograms of ethinylestradiol and 150 micrograms of levonorgestrel in each active pill. Seasonale reduces the frequency of menstrual periods from thirteen per year to four per year by changing the regimen of active pills from 21 to 84. Each package has 84 active pills and seven placebo pills to be taken at the end of the active cycle.
Seasonique, also produced by Duramed Pharmaceuticals, has active pills and packaging identical to Seasonale, but replaces the placebo week with a low-dosage week of estrogen.
Lybrel is produced by Wyeth Pharmaceuticals.  It contains 90 mcg levonorgestrel and 20 mcg ethinyl estradiol in each pill, and is designed to be taken continuously with no placebos.

# History
Seasonale was first developed by Barr Pharmaceuticals, alongside Eastern Virginia Medical School, under an agreement. The FDA approved Seasonale on September 5 2003.  Barr Pharmaceuticals, its manufacturer, claimed at the time of Seasonale's approval that it would cost one dollar per pill. Seasonale is one of Barr Pharmaceuticals' 22 oral contraceptive products.
The FDA approved Lybrel for human consumption on May 22 2007. Lybrel is expected to be made available to the public in the United States by July 2007.

# Further reading
- Elsimar M. Coutinho (1999). Is menstruation obsolete?. Oxford: Oxford University Press. ISBN 0-19-513021-9. Unknown parameter |coauthors= ignored (help).mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
- Susan Rako (2006). The Blessings of the Curse: No More Periods?. Lincoln, NE: Backinprint.com. ISBN 978-0595386550.