question: Why is a male contraceptive pill not yet available?
comment: Because ovulation in women is relatively easy to control with hormones, while sperm production is far more difficult to control without causing huge side effects. The "TL;DR" for this is that stopping ovulation in women is exploiting an existing biological function, while there is no such extant function to stop sperm production. In Women, Ovulation can be prevented by using pills that mimic the hormones released immediately after ovulation, essentially telling the body "You don't need to release an egg because you already did, silly!" In men, there's no such hormone control. Sperm is made constantly unless you completely wipe out the hormones required, which can potentially lead to permanent infertility. Speaking of, virtually every attempt at a male contraceptive pill has lead to permanent sterility in up to a 5th of all trial participants. About the only promising pills currently in development (All at least 5 years away) are drugs that stop the Sperm from entering the egg effectively, however many of these are Calcium-Channel-Blocker class drugs, which means they have a myriad of other effects that must be considered.
passages: In 2001, Dutch pharmaceutical company Organon announced clinical trials of its implantable etonogestrel-based male contraceptive would begin in Europe and the U.S., anticipating a marketable product as early as 2005. Despite promising results, research development stopped, with outside speculation that lack of marketability was a factor. Organon representative Monique Mols stated in 2007 that "[d]espite 20 years of research, the development of a [hormonal] method acceptable to a wide population of men is unlikely." Schering/Bayer had been working on a similar annual implant with quarterly injections but cancelled the research in 2006/2007, declaring that men would most likely view it as "not as convenient as a woman taking a pill once a day."
   A goal of research is to develop a reversible male contraceptive, either pharmaceutical, surgical or other.
  
  Section::::Research.:Medications.
  
  Two delivery methods are currently under active study: male hormonal contraceptives that can be taken in pill form by mouth, similar to the existing birth control pill for women and male hormonal injections.
  
  BULLET::::- Gossypol, an extract of cotton, has been studied as a male contraceptive pill. It decreased sperm production; however this is permanent in 20% of people.
   Section::::Men.
  
  Several barriers exist to expanding research into implantable and other contraceptive methods for men, including vague regulatory guidelines, long device development timelines, men's attitudes towards convenience, and a significant lack of funding. Several implantable devices have been attempted, both hormonal and non-hormonal.
  
  Section::::Men.:Research.
   The Pill is currently classified as a prescription medicine in New Zealand. However, there is debate over whether it should be reclassified as restricted medicine, which would allow it to be sold over the counter in pharmacies throughout the country. The company Green Cross Health Ltd has lobbied to the Medicine Classifications Committee for reclassification since 2014. The Classifications Committee has stated that it is concerned that sidelining the role of doctors in prescribing contraception may result in inadequate counselling and advice on sexual health. Green Cross has stated that pharmacists are 'well equipped to consult with women about their contraceptive needs' and also claims that women would find it more convenient.
   In Japan, lobbying from the Japan Medical Association prevented the pill from being approved for general use for nearly 40 years. The higher dose "second generation" pill was approved for use in cases of gynecological problems, but not for birth control. Two main objections raised by the association were safety concerns over long-term use of the pill, and concerns that pill use would lead to decreased use of condoms and thereby potentially increase sexually transmitted infection (STI) rates.
   In 2005, a collaboratory project led by the Population Council, the University of California, Los Angeles, and the Medical Research Council began researching a matchstick-sized implant that contains MENT (7α-methyl-19-nortestosterone or Trestolone), a "synthetic steroid that resembles testosterone." Clinical trials were set to begin in 2011 or 2012, and the project was ongoing as of 2016, with hopes of gaining approval as the first reversible male contraceptive.
   BULLET::::- RISUG consists of injecting a polymer gel, styrene maleic anhydride in dimethyl sulfoxide, into the vas deferens. The polymer has a positive charge, and when negatively charged sperm pass through the vas deferens, the charge differential severely damages the sperm. A second injection washes out the substance and restores fertility. , RISUG is in Phase III of human testing in India and has been patented in India, China, Bangladesh and the United States. Vasalgel is a brand name of polymer gel injection that is being tested in the United States. Testing on rabbits and primates showed positive results.
   BULLET::::- Calcium channel blockers such as nifedipine may cause reversible infertility by altering the lipid metabolism of sperm so that they are not able to fertilize an egg. Recent Research at Israel's Bar-Ilan University show that as of June 2010, such a pill may be five years away. Testing it on mice has been found to be effective, with no side effects.
   BULLET::::- Multiple male hormonal contraceptive protocols have been developed. One is a combination protocol, involving injections of Depo-Provera to prevent spermatogenesis, combined with the topical application of testosterone gel to provide hormonal support. A similar proposal consists of yearly subdermal implant administering a synthetic testosterone compound (7α-methyl-19-nortestosterone) combined with regular injections of Depo-Provera. The implant alone (without Depo-Provera injections) has been shown to already sufficiently reduce sperm count in most of the subjects given the highest tested dosage in a Phase II trial. Another is a monthly injection of testosterone undecanoate, which recently performed very well in a Phase III trial in China.
   two forms of combined oral contraceptives are on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system.
   BULLET::::- On June 10, 2013, the Obama administration ceased trying to block over-the-counter availability of the pill. With this reversal it means that any person will be able to purchase the Plan B One-Step without a prescription.
  
  Section::::See also.
  
  BULLET::::- Rape crisis center
  
  BULLET::::- Reproductive Health Supplies Coalition
  
  Section::::External links.
  
  BULLET::::- Emergency Contraceptive Pills Medical and Service Delivery Guidance 4th edition
  
  BULLET::::- The Emergency Contraception Website (not-2-late.com)by the Office of Population Research at Princeton University and the Association of Reproductive Health Professionals. Information for women who need emergency contraception now.
   The United States Senate began hearings on the pill in 1970 and there were different viewpoints heard from medical professionals. Dr. Michael Newton, President of the College of Obstetricians and Gynecologists said:
   HRA Pharma changed its packaging information for Norlevo (levonorgesterel 1.5 mg, which is identical to many other EHCs) in November 2013 warning that the drug loses effectiveness in women who weigh more than 165 pounds and is completely ineffective for women who weigh over 176 pounds.
  
  Section::::Emergency contraceptive pills.:Safety.
   BULLET::::- August 12 – Former President Jimmy Carter reveals that he is being treated for brain cancer.
  
  BULLET::::- August 18 – The White House confirms that Haji Mutazz, deputy to ISIS leader Abu Bakr al-Baghdadi, has been killed in a U.S. airstrike near Mosul, Iraq.
  
  BULLET::::- August 19
  
  BULLET::::- The U.S. Food and Drug Administration approves the drug flibanserin, sometimes called the "pink pill" or the "female Viagra", designed to boost women's sexual desire.
   In January 2016 news broke of a non-hormonal, implantable valve — the Bimek SLV — with a switch that attaches to the vas deferens, allowing the owner to stop and resume the flow of sperm on demand. A clinical trial of 25 participants was announced to further test the efficacy of the device.
  
  Section::::Other animals.
   In 2010, the United Nations launched the "Every Woman Every Child" movement to assess the progress toward meeting women's contraceptive needs. The initiative has set a goal of increasing the number of users of modern birth control by 120 million women in the world's 69 poorest countries by the year 2020. Additionally, they aim to eradicate discrimination against girls and young women who seek contraceptives. The American Congress of Obstetricians and Gynecologists (ACOG) recommended in 2014 that oral birth control pills should be over the counter medications.
   In February 2016, the FDA issued a "black box" label to warn the public about the harmful complications associated with the use of this device and requested Bayer to conduct a new postmarket surveillance to follow 2,000 women for at least three years, comparing the effectiveness and safety of the device with other surgical contraceptive methods. Women and doctors were required to sign a decision checklist before Essure implantation, and to give consent to a test three months later to ensure the device was properly placed and functioning.
  
  Section::::External links.
  
  BULLET::::- Essure Procedure by Erin Brockovich
   BULLET::::- Inhibition of chromatin remodeling by binding to a pocket on BRDT has been shown to produce reversible sterility in male mice. JQ1, a selective BRDT inhibitor which acts in this manner, is currently under development as a non-hormonal male contraceptive drug. It effectively blocks the production of sperm by the testes, and lacks the adverse effects of previously researched hormonal contraceptives for men.
  
  BULLET::::- Immunocontraception targeting sperm antigens has been found to be effective in male primates.
   BULLET::::- Vas-occlusive contraception consists of partially or completely blocking the vas deferens, the tubes connecting the epididymis to the urethra. While a vasectomy removes a piece of each vas deferens, the "intra vas device" (IVD) and other injectable plugs only block the tubes until the devices are removed. The U.S. Food and Drug Administration (FDA) approved human clinical trials for the intra-vas device in 2006.
  
  Section::::Research.:Other.
   Section::::History.:Public availability.
  
  Section::::History.:Public availability.:United States.
   BULLET::::- Reversible inhibition of sperm under guidance: RISUG, formerly referred to as the synthetic polymer styrene maleic anhydride (SMA), is the development name of a male contraceptive injection developed at IIT Kharagpur in India by the team of Dr. Sujoy K Guha. Phase III clinical trials are underway in India, slowed by insufficient volunteers. It has been patented in India, China, Bangladesh, and the United States. A method based on RISUG, Vasalgel, is currently under development in the US.
   The Today Sponge was developed beginning in 1976 and introduced in the United States in 1983. Today was removed from the market in 1994 due to manufacturing problems. Following several delays, the Today brand became available again in Canada in March 2003, and in the U.S. in September 2005. After the manufacturer's parent company declared bankruptcy in 2007, production was shut down again, until the new manufacturer, Mayer Laboratories Ltd., reintroduced Today to the U.S. market in 2009.
  
  Section::::History.:Pharmatex sponge.
  
  The Pharmatex sponge was introduced in France and the Canadian province of Quebec in 1984.
  
  Section::::History.:Protectaid sponge.
   BULLET::::- Research on the safety and effectiveness of using ultrasound treatments to kill sperm has undergone since the idea originally came about following experiments in the 1970s by Mostafa S. Fahim who noticed ultrasound killed microbes and decreased fertility. As of 2012 a study conducted on rats found that two 15-minute treatments of ultrasound delivered 2 days apart in a warm salt bath effectively lowered their sperm count to below fertile levels. Another small study involved dogs, and found that after three ultrasound applications the dogs' ejaculate contained no sperm. Further experiments on its effectiveness on humans, the longevity of the results, and its safety have yet to be conducted.
   BULLET::::- Phenoxybenzamine has been found to block ejaculation, which gives it the potential to be an effective contraceptive. Studies have found that the quality of the semen is unaffected and the results are reversible by simply discontinuing the treatment.
  
  BULLET::::- Trestolone is an anabolic steroid that has been shown to significantly reduce sperm count.
  
  BULLET::::- A male birth control pill based on ouabain, a plant extract used by traditional African hunters to stop the hearts of game, has been shown to reduce sperm motility sufficiently for effective contraception in rats.
   Senestech's first product ContraPest® is a contraceptive pest control designed to reduce fertility in brown and black rats. It is a flavored liquid, designed to be attractive to, and to be consumed by, the target animals in order to reduce the population over time. ContraPest is a contraceptive, not a sterilant, so a continuous supply is required to maintain reduced populations.  ContraPest was initially tested in Indonesian rice fields, South Carolina pig farms, the suburbs of Boston and the New York City subway, and caused a reduction in rat populations of roughly 40% over a period of 12 weeks.  ContraPest was submitted for registration with the U.S. Environmental Protection Agency on August 23, 2015, and the EPA granted registration approval for ContraPest effective August 2, 2016. Removal of the "Restricted Use Only" label from ContraPest was ordered by the EPA in October 2018. The active ingredient of ContraPest is the chemical 4-vinylcyclohexene diepoxide (VCD), which is a known killer of oocytes in immature ovarian follicles. ContraPest also contains triptolide, which the company reports has adverse reproductive effects on both males and females.
  