There are various behavioral methods of contraception available. The most effective way to prevent pregnancy is through total abstinence. Other methods include the rhythm method, which involves abstaining from sexual intercourse during the fertile periods around ovulation. The fertile period typically spans from 3 to 4 days before ovulation until 3 to 4 days afterward. Another method is withdrawal before ejaculation, also known as coitus interruptus. However, both of these methods have higher failure rates (20%–30%) compared to barrier methods (2%–12%), intrauterine devices (IUDs) (<2%), and oral contraceptives (<1%). The use of barrier methods such as condoms or diaphragms is more effective when combined with spermicidal jellies. Among all the methods, only condoms provide effective protection against sexually transmitted diseases for sexually active individuals. IUDs are relatively effective as they prevent implantation by inducing an inflammatory response in the endometrium. Some types of IUDs contain copper, zinc, or progestins, which inhibit sperm transport or viability in the female reproductive tract.

Oral contraceptives have been available in the United States since the early 1960s. The current doses of steroids used in oral contraceptives are significantly lower than those used 35 years ago. When used correctly, oral contraceptives have a low failure rate. There are many different types of oral contraceptives available on the market today. Over the years, the trend has been to decrease the dosage of steroids used due to dose-dependent side effects. Oral steroidal contraceptives either contain a combination of an estrogen and a progestin or a progestin alone. They work through multiple mechanisms, with most of them blocking the LH surge that triggers ovulation. However, some pills, such as the progestin-only minipill, do not prevent LH surges. Fertility is also blocked by altering the nature of cervical mucus, modifying endometrial development, or regulating fallopian tube motility. As these contraceptives suppress FSH, they impair early follicular development.

Emergency contraception involves hormonal treatment designed to inhibit or delay ovulation, inhibit corpus luteum function, disrupt the function of the oviducts and uterus, or a combination of these mechanisms. It is used in cases such as sexual assault or failure of a barrier method, like a ruptured condom. There are more than 20 commercially available "morning-after" pills. The currently preferred medication is levonorgestrel (Plan B), which is a synthetic progestin-only pill. The efficacy of the pill decreases as the time taken after intercourse increases. The exact mechanism of action is not known, and the treatment has no effect if implantation has already occurred.

Medical (hormonal) termination of pregnancy (abortion) can be achieved up to 49 days' gestation by administering mifepristone (RU-486), a progesterone receptor antagonist that induces the collapse of the pregnant endometrium. Mifepristone is followed 48 hours later by the ingestion or vaginal insertion of a synthetic prostaglandin E (e.g., misoprostol), which induces myometrial contractions.

In lactation, milk is not obtained by applying negative pressure to the breast through suckling. Instead, milk is actively released through a neuroendocrine reflex. The release of oxytocin and milk let-down can be triggered by psychogenic stimuli, such as the mother hearing a baby crying on television or thinking about her baby. However, such psychogenic stimuli do not affect the release of PRL.
Therearemultiplebehavioralmethodsofcontraception. Totalabstinenceisthebestwaytoavoidgettingpregnant.Othermethodsincludetherhythmmethod,whichreliesonabstinencefromsexualintercourseduringfertileperiodsaroundthetimeofovulation.Thefertileperiodextendsfrom3to4daysbeforethetimeofovulationuntil3to4daysafterward.Asecondmethodiswithdrawalbeforeejaculation,coitus interruptus. Boththesemethodshavehigherfailurerates(20%–30%)thanbarrier methods (2%–12%),intrauterine devices (IUDs) (<2%),andoral contraceptives (<1%)do.Barrierssuchascondoms ordiaphragms aremoreeffectivewhenusedwithspermicidal jellies. Ofallmethods,onlycondomsprovideeffectiveprotectionfromsexuallytransmitteddiseasesinsexuallyactiveindividuals.IUDsarerelativelyeffective.Theypreventimplantationbylocallyproducinganinflammatoryresponseintheendometrium.SomeformsofIUDscontaincopper,zinc,orprogestins,whichinhibitspermtransportorviabilityinthefemalereproductivetract.
OralcontraceptiveshavebeenmarketedintheUnitedStatessincetheearly1960s.Thedosesofsteroidsusedtodayaresignificantlylowerthanthoseused35yearsago.Properlyused,oralcontraceptiveshavealowfailurerate.Manyformsoforalcontraceptivesaremarketedtoday.Thetrendovertheyearshasbeentodecreasethedosageofsteroidsusedbecausethesideeffectsaredosedependent.Alloralsteroidalcontraceptivescontaineitheracombinationofanestrogenandaprogestinoraprogestinalone.Oralcontraceptivesworkthroughmultiplemechanisms.MostblocktheLHsurgethattriggersovulation.However,somepills(e.g.,progestin-onlyminipill)donotpreventLHsurges.Fertilityisalsoblockedbychangingthenatureofcervicalmucus,alteringendometrialdevelopment,orregulatingfallopiantubemotility.BecausethesecontraceptivessuppressFSH,theyimpairearlyfolliculardevelopment.
Emergency contraception involveshormonaltreatmentdesignedtoinhibitordelayovulation,inhibitcorpusluteumfunction,disruptthefunctionoftheoviductsanduterus,oranycombinationofthesemechanisms.Forexample,candidatesforemergencycontraceptionincludewomenwhoaresexuallyassaultedorwhoexperiencedfailureofabarriermethod(e.g.,rupturedcondom).Therearemorethan20typesofcommerciallyavailable“morning-after”pills.Thecurrentlypreferredmedicationislevonorgestrel (Plan B), whichisasyntheticprogestin-onlypill.Theefficacyofthepillisinverselycorrelatedwiththetimeitistakenafterintercourse.Theexactmechanismofactionisnotknown.Treatmenthasnoeffectifimplantationhasoccurred.
Medical(hormonal) termination ofpregnancy(abortion)canbeachievedupto49days’gestationbyadministrationofmifepristone (RU-486), aprogesteronereceptorantagonistthatinducescollapseofthepregnantendometrium.Mifepristoneisfollowed48hourslaterbyingestionorvaginalinsertionofasynthetic prostaglandin E (e.g.,misoprostol),whichinducesmyometrialcontractions.
alveolar and ductal lumens. Thus the nursing infant does not gain milk by applying negative pressure to the breast from suckling. Rather, milk is actively ejected through a neuroendocrine reflex. Oxytocin release and milk let-down can be induced by psychogenic stimuli such as the mother hearing a baby crying on television or thinking about her baby. Such psychogenic stimuli do not affect PRL release.