How Does the Birth Control Pill Work?

When I was nineteen I saw my doctor regarding ongoing medical problems with my menstrual cycle during that visit my doctor prescribed an oral contraceptive otherwise known as the birth control pill.  It was his catch-all response to any reproductive medical problem I presented and unfortunately many women face the same outcome. They go to their doctor seeking medical guidance and assistance for their reproductive health only to be told “Take the birth control pill.” Without any additional assistance offered and often with their doctors glossing over the serious health risks, such as blood clots, strokes, cancers and harm to the overall environment associated its usage Further, when I took the prescription from him I, like many women, did not know the birth control pill also could work as an abortifacient.  After reading more about it and talking with women over the years I have been surprised to find how many other women were not aware of this.

How does the birth control pill work? 

Well, the birth control pill has three mechanisms in preventing pregnancy.  The first two mechanisms are contraceptive (working against or contra the natural order) in their nature and the third mechanism is both contraceptive and abortive. The first mechanism works via the hormones within the contraceptive to prohibit ovulation and no egg (ovum) is released.  The second mechanism causes a thickening of the woman’s cervical mucus to prevent sperm from being able to properly function hindering its motility and preventing the sperm from possibly fertilizing the egg.  Finally, there is the third mechanism and this is the one mechanism that is the abortifacient aspect of this form of contraception.  The third mechanism works as such that birth control pill causes the lining of the endometrium to thin out to the point that it becomes unable to sustain the implantation of the newly-fertilized egg.

What this means is if the first two mechanisms fail to work in their contraceptive nature then the woman’s egg is released during ovulation and as a result the egg could become fertilized by her husband’s sperm and the result is a human embryo.  A human embryo contains the entire DNA of the newly formed human being; fully human in scientific terms.  However, the third mechanism of the oral contraceptive through its thinning of the uterine lining attempts to prevent the newly formed human embryo from implanting.  The final result in this case could be the aborting of the human embryo.  The makers of the birth control pill state it is indeed a mechanism of how pregnancy is prevented and they have no reason to lie.  In fact, it would probably benefit them to keep that point a secret when one thinks about it.

Additionally, many people don’t realize is that the morning after pill works in the same fashion with the same three mechanisms as the regular birth control pill.  Think about it as a society many recognize the dangerous aspects of using the morning after pill (emergency contraception) because it can prevent implantation but do not know that the birth control pill also does the same thing. In fact, a version of emergency contraception may be simply taking a higher dosage of the birth control pill or using an IUD.

Moreover, how many babies are born each year to women who thought that the birth control pill would prevent a pregnancy? According the CDC the birth control pill in its various forms is only 92%-99% effective meaning that we know for a fact that sometimes all three mechanisms “fail” and implantation occurs thus it is logical, based on the birth control pill’s own stated facts of how it works, that some human embryos are aborted via this third mechanism.

I also want to state I am not writing this to argue with, scare or condemn anyone for past or present choices but to help provide information that I know I once did not have. When we know better, we can do better. Also as Catholics we have the ability to receive forgiveness available through the Sacrament of Reconciliation if we have willingly engaged in contraception to plan our families.  If we have a serious or just reason to avoid a pregnancy, discerned through prayer as a couple, then we may use Natural Family Planning (which is as effective when properly used as the birth control pill) to work with God in this need versus against (contra) God. If we are seeking medical treatment we have the ability to now turn to Natural Family Planning doctors (such as Pope Paul VI Institute) who may be able to help us and provide medical treatments without violating our beliefs on life.

Further, as women who may suffer with various reproductive health problems that the birth control is prescribed to supposedly treat (which it does not, it only masks these problems, managing at most to deal with symptoms not treatments) we deserve better.  We deserve medical treatments that work with the natural order as God intended, as many Natural Family Planning doctors actively work to do. However, we deserve not only for Natural Family Planning doctors to do this but for the medical community at large to research more into the root cause(s) of various reproductive health problems we as women may face, improving our overall health, and to provide us with medical alternatives to the birth control pill that do not work against human life while working with God and His natural order.

  • HelenJanuary 20, 2012 - 2:15 pm

    I wish more women understood what they were doing to their bodies by taking oral contraceptives. Oral contraceptives are classified as a group 1 carcinogen by the World Health Organization…and the WHO is certainly not a pro-life group. Instead of masking our femininity we should be celebrating it, understanding it and cooperating with it. It is the way God made us!ReplyCancel

    • BethJanuary 20, 2012 - 3:15 pm

      @Helen–exactly, we as women deserve more. It is truly awful to think how many have been mislead to believe that the pill “is the best” we deserve and we are just to ignore the myriad of negative effects it has on us.ReplyCancel

  • KarynJanuary 20, 2012 - 2:59 pm

    I think one of the tricky things about people like you or I getting the word out is that people see large families like ours and would never take our word on contraception – as obviously our method, in their eyes, doesn’t work! I can point out that I purposefully “allowed” for the conception of my five, but people are in disbelief that I would do such a thing.

    But I began using fertility awareness before entering the Church just because of the physical damage of birth control – and that’s what I hope will lead society away from the pill and IUDs and such.ReplyCancel

    • BethJanuary 20, 2012 - 3:45 pm

      @Karyn-I agree, it is hard to combat stereotypes when relating important information. However, hopefully as the existing research on fertility based methods for natural family planning and the larger harms caused by oral contraceptives (& other methods) to those using them becomes public knowledge people will go beyond stereotypes to understand why it is important to work with our bodies and the natural order versus against. I have the same hope that the more we talk about it that it may lead more people to be open to learn about Catholic teaching on marriage & family as well.ReplyCancel

  • KristineJanuary 21, 2012 - 7:22 am

    To clarify a previous comment, oral contraceptives can possibly lead to certain types of cancer, but they can also possibly be beneficial in preventing other types of cancer. As with most things, a researched approach is best to deciding whether or not it is right for you. The bcp made my life much, much more manageable in my college years, when I would spend 3 to 4 days every month in bed, sick. And they have also been beneficial in regulating my cycles to achieve fertility in my married life. Sometimes a woman’s “natural” functions can use a little tweaking.ReplyCancel

  • BethJanuary 21, 2012 - 8:27 am

    @Kristine-I completely agree that some women {like us} may need medical treatments! I agree we need treatments that assist us to continue with being able to function when we suffer with serious reproductive health problems. But we should also have more medical research into the underlying cause(s) of the problems we face & not merely a superficial management of our sympotomology. Additionally, there is assistance to the female body with serious reproductive health problems that can be had without the use oral contraceptives, although it may still require the usage of synthetic hormones as part of a larger treatment of the underlying problem. Women who suffer do need treatments but the prescribing for the off-label usage of bcp {as they aren’t approved for treatment} to manage symptoms without seeking to treat the underlying medical conditions is not the best we have or the best we should settle for.

    Further, while the research has shown bcp usage may correlate to a decrease of certain cancers there is an increase in other cancers (see: and the two cancers (endrometrium and ovarian) that bcp has been posited to possibly reduce are reduced by pregnancy & breastfeeding, bcp is a synthetic substitute for the natural order (

    I completely agree women should research more to find what is best for them. We are our own best advocates & as we ask more questions perhaps we will see more options available to us.ReplyCancel

  • MeganJanuary 21, 2012 - 10:20 am

    Great entry! My doctors have always done the same thing when I’ve expressed concern regarding my abnormal cycle. I have finally gone completely off the birth control pill in August due to two reasons: I finally learned how horrible it is for me and the fact that it can cause abortions and I do not want to prevent the natural union between my husband and myself anymore. Additionally, my desire to become a member of the Catholic Church is the reason I learned about its ill effects. In fact, I am now open to life.ReplyCancel

  • justmeJanuary 21, 2012 - 3:01 pm

    Greetings from Finland (and thus sorry for my poor English)! 🙂 And congratulations for this amazing blog. What a pity we don’t have such good Catholic websites here in Europe…

    My doctor told me to take the pill when I was 13 – because of acne. Can you believe it? Luckily I somehow “felt” it was not right, although nobody had ever spoken to me about the pill (not counting the compulsory atheist sex indoctrination classes at school, where it was presented as some kind of healthy candy). So I said no. But sadly, because of further indoctrination, I started taking it when I was 20. But then my life changed. After coming back home from the World Youth Day in Madrid last August, I threw away all of that poison, including one unopened package! Now I feel so free!! 🙂 God bless you all.ReplyCancel

  • EmilyJanuary 21, 2012 - 3:50 pm

    Chock full of fabulous information… Great post, Beth!ReplyCancel

  • ANNJanuary 21, 2012 - 5:01 pm

    Well-done post; thanks for trying to educate others about the horror of what these artificial hormones do. I still wonder if my taking them had something to do with my breast cancer diagnosis, as it is my only risk factor besides age.
    Your reference to Creighton-NFP doctors is a mucus-only single-sign system. I hope you can refer your readers to an excellent online reference to temperature and cervix signs as well. Being a nurse, I like to let couples know all that there is in NFP science. Then they can decide which signs are useful for them. NFP International also has a nice discussion of breastfeding/fertility and theology.
    We used natural family planning to space our 7 children and especially needed the temperature sign when avoiding a baby.ReplyCancel

  • ErikaJanuary 22, 2012 - 12:01 am

    You stole my idea!! 🙂 I wrote an exposé on bcp, but I was a few days too late! Great coverage!

    As for the cancer preventative aspects of bcp… You already did an excellent job countering that argument. However, as a survivor, I have a slightly different voice. My breast oncologist and gynecology oncologist will NOT prescribe bcp or any other hormones to me because of my cancer survival. I don’t have any female parts left to get cancer, but the risk of those cells still being present and growing into tumors is higher than any benefits. Since I was only 28 at my breast cancer diagnosis, it stands to reason that other women this age (and even younger) could have genetic predispositions for cancer that is unknown to them (and their doctors). That means that widespread use of bcp can actually be increasing the numbers of cancers in young women. In fact, a research group from MD Anderson has not been able to identify why women with hereditary cancers are being diagnosed with active tumors about 10 years earlier than others in their family. To me that is more than enough reason to avoid bcp!ReplyCancel

  • BethJanuary 22, 2012 - 9:34 am

    @Megan–Welcome home to the Church! It is wonderful to read how your interest in coming into the Church helped you look not only at the medical concerns but the spiritual ones!ReplyCancel

  • BethJanuary 22, 2012 - 9:40 am

    @Justme-Welcome to our little corner of the Internet! Isn’t it great that we have the ability to connect as a worldwide faith? Thank you for sharing your story.ReplyCancel

  • BethJanuary 22, 2012 - 9:41 am

    @Emily- Thanks! I hope we can continue to get more of this information out there for women (& men) to have access to.ReplyCancel

  • BethJanuary 22, 2012 - 9:52 am

    @Ann-Hopefully we will be having more posts with additional information on NFP with additional information, because you are right there are several great methods of NFP to choose from! I selected only one as an example, but I did link to two NFP doctor & method resources.

    However, it is good to give more direct links to some great resources for different methods (this is not an all-inclusive list):

    Also, prayers on having a healthy outcome for your diagnosis!ReplyCancel

  • BethJanuary 22, 2012 - 9:57 am

    @Erika-I think you should still write a post that delves deeper into this topic & the cancer data. The more information that can be given to assist women in this matter the better!ReplyCancel

  • MartinaJanuary 22, 2012 - 1:28 pm

    There is definitely a shortage of articles out there that highlight the dangers of the BCP, so I think the more we can get, the better! Erika…I’m looking at you, lady. 😉ReplyCancel