Just a gram or two of sugar makes the estrogens go down...
June 8, 2013 3:36 PM   Subscribe

Can you answer a few questions related to hormonal birth control? Science questions, I mean!

The layman's explanation for the function of hormonal birth control is that it takes advantage of the mechanism that suspends ovulation during pregnancy, and it's generally explained as tricking the body into thinking it is pregnant. Is this the case or is it something completely different?

The risk of certain cancers go up or down related to whether a person has been pregnant, breast feeding or on hormonal birth control. Is the cancer increases and decreases similar for pregnancy and hormonal birth control?

The hormones in the pills are synthetics- a friend of mine, who did a study on rivers and lakes and waste water, showed that the presence of urine from humans dumped into the water caused feminization of waterlife and that this was caused because synthetic compounds are much more stable than the normal amounts of hormones a healthy woman pees out (and administered at several times higher than normal dosing). How many compounds do they have for synthetic estrogens and progesterones that are currently seen as safe for human consumption?

I know that hormonal birth control pill brands/types generally combine hormones in proprietary ways and that's what makes the difference between say, Yasmine and Tri-Cyclen. Are there optimal combinations of chemical pairs and dose levels?

I've been told conflicting information, that there's no evidence that continuous dose treatments that suspend menstruation harm the body, and that it's simply not something that's been studied enough. Even hormonal longer term options give a menstruation week, albeit on longer time scale. Why? Does the uterus eventually need to shed anyway?

Back when I started the pill as a teen, my doctor advised me to wait X number of days after my period started. By the time I was in my twenties, doctors just told me to start whenever. Was there any reason to the old method other than counting?

I have less acne on the pill. How does it do that?

It seems to cause poor circulation in my hands and feet, which I experience as soreness, tough in my case only when I'm already tired. What mechanism allows the synthetic hormones to effect my circulatory system?

How does hormones cause breast swelling and shrinking?
Mine can have two cup sizes in difference, on and off the pill. some of this appears to be whole body fluid retention, but it's most noticeable in the breasts themselves, and for a while, more dominant on the right side by a hugely noticeable margin. What cells are filling or swelling?
posted by Phalene to Science & Nature (9 answers total) 7 users marked this as a favorite
IANAD but I have been on various hormonal oc's.

1. Planned parenthood has a great page that talks all about how oral contraceptives work. Click the tab "How Do Birth Control Pills Work?

2. Here is the NIH page about oral contraceptives and cancer risks. It refers to a number of studies if you need further info.

3. I have no idea.

4. My understanding is that this depends person to person. If a woman gets migraines, for example, the combined pill is not an optimal choice. Or if a woman needs to focus on regulating her cycle, she might be benefited by a different combination than someone trying to reduce cramping.

5. I think the reason for non active pills is mostly that people flip out less if they have a period so they know they aren't pregnant.

6. If you are trying to regulate your cycle on the pill and you are young, it might help to start right after your period because your non-active pills might come when your regular period would. If you're switching pills this may not be as much of an issue. But once again IANAD.

7. Regulating hormones means regulating acne too! Added bonus :)

8. Ask your doctor. This strikes me as unique.

9. Go ask Alice answers this question exactly!
posted by donut_princess at 4:19 PM on June 8, 2013

The answer to a lot of this is going to be "no one knows".

We don't have really in-depth analysis on a lot of this information. If one of the pills were inherently more 'optimal' than the others in a known way, the others wouldn't be sold any more. We're still discovering the cancer increases and decreases, and for instance different responses seem to be associated with different genetic backgrounds (certain genes were said, at least a few years ago, to be associated with having your breast cancer rate go up under hormones).

We don't even really understand the effects of pregnancy. Some women's breasts get larger, some stay the same; some women have nausea, some don't; some women... etc.
posted by Lady Li at 4:20 PM on June 8, 2013

Why? Does the uterus eventually need to shed anyway?
No. The original makers of the Pill did not include the placebos but they found that women were uncomfortable not having periods. I was on NuvaRing for several years and I always "stacked" them to skip my periods. Stopped and was pregnant within two months.

Are there optimal combinations of chemical pairs and dose levels?
There are optimal combinations for individuals, because every woman has her own unique hormonal profile. Yaz made me suicidal, other women love Yaz. NuvaRing was my BFF, other woman have very adverse reactions. Women prone to migraines shoukd not take pills with esteogen. Etc. That's why there are so many formulas on the market.

Are the cancer increases and decreases similar for pregnancy and hormonal birth control?
My understanding is that pregnancy and birth control lower ovarian cancer risk because these statuses reduce the number of times a woman ovulates. Ovulation is sort of a violent process and it can begin to have a higher likelihood of going wrong closer to menopause, leading to cancer.

Was there any reason to the old method other than counting?
For me this was start on the Sunday after the first day of your period, which most likely had to do with the labels on the pill pack and making it easier to keep track of your daily dosage.

I would read donut_princess's links, because a lot of your questions will be answered there.
posted by emkelley at 4:36 PM on June 8, 2013

Yes, the function of a birth control pill is to fool the woman's body into thinking it's pregnant.

The reason they use synthetic hormone analogues is that the actual hormone they're simulating (progesterone) has a relatively short half-life in the body. In a real pregnancy, the uterus produces the hormone constantly, and it's constantly being broken down in the liver. In order to make it possible to take one pill a day without it being the size of your thumb, they had to find an analogue which was recognized as the hormone by the body, but which was broken down much more slowly by the liver.

Since the first one was created, back in the 1960's, a lot of research has gone into finding variations of that analogue which might have better properties. Several have been found, and that's why different pills from different vendors have different mixtures of active ingredients.

As to why the one-week of non-active pills leading to menstruation, I think it was mainly that the original researchers decided it was better to be safe than sorry. Is menstruation necessary? I don't think anyone knows. But they all know this: the first woman who doesn't menstruate and suffers health problems because of it is going to sue the drug company for a trillion dollars. So no one wants to walk into that mine field.
posted by Chocolate Pickle at 5:11 PM on June 8, 2013

Here is a very in-depth discussion of why the birth-control pill has a "bleeding" placebo week.
John Rock's Error
tl;dr By mimicking the natural process, the Pill could be made acceptable to Catholics.
posted by fiercecupcake at 5:17 PM on June 8, 2013

Best answer: I must refer you to this old AskMe comment (and follow-ups) by Steven C. Den Beste on the mechanics of hormonal birth control.

This old MeFi post about the co-inventor of the Pill also talks about how the original version of the pill didn't have breaks for menstruation, but the break was added because they were hoping it would make birth control seem more 'natural' and therefore acceptable to the Catholic Church. (on preview, same article as linked by fiercecupcake; perhaps you'd like to read the MeFi comments too)

I would also recommend picking up a copy of The Story of V if you're super-interested in what we know about the female body.
posted by heatherann at 5:22 PM on June 8, 2013 [1 favorite]

Best answer: As an introductory statement I'd like to point out that hormones, like any part of the endocrine system, are ancient molecules that are present in nearly all animals and it is a very complicated subject with many counter-intuitive aspects, endless amounts of domino effects and feedback loops. Estrogen has an effect on nearly every part of your body, however minimal it may be. So now that we have established that this is a complicated topic with a smidge of controversy and more than a little bad scientific design (thanks big pharm!). I will attempt to answer your questions with the science that was accepted as the current theory at the time I learned this topic, +/- five years ago.

1. Depends. Some birth control pills do prevent ovulation, some prevent implantation of the egg (fertilized or not) in the uterus. This is a function of whether it is estrogen, progesterone, or both, and if the pill includes both, in what ratio.

Is the cancer increases and decreases similar for pregnancy and hormonal birth control?
The leading theory on the data for breast cancer says that pregnancy before 30 (slightly) lowers your risk of developing breast cancer, whereas nothing has been proven as far as the effect of hormonal birth control on breast cancer risk.

Are there optimal combinations of chemical pairs and dose levels?
The glib answer is that there is an optimal combination for you, sure, most likely. There is not an optimal combination for everyone. There's not enough data on this, to answer your real question.

Does the uterus eventually need to shed anyway?
Not really. There hasn't been any proof the uterus needs to menstruate. There is definitely a psychological component at play, the recent pills that entirely prevented menstruation ran into some problems where people "didn't feel right."

Was there any reason to the old method other than counting?
Technically you're supposed to still time the start of taking hormonal birth control, since timing the change in hormones can have all kinds of effects, including affecting your mood, but doctors have gotten really sloppy about this and I can't even remember the last time a pharmacist advised me about anything.

With regards to hormones and stuff in your water, yeah. It's probably a lot worse than we are willing to admit. I remember back in the early 90s scientists were freaking out about how entire species of amphibians in the USA are going extinct / mutating due to all the various estrogen family compounds in the water. Last time I checked, the frog population is toast. Could be a lot of other factors involved in that, though.

I have less acne on the pill. How does it do that?
Estrogen/progesterone affect the skin significantly in terms of hydration, thickness and oil production, thus the glowing radiance of pregnant women. Skin changes after menopause are also a significant difference.

What mechanism allows the synthetic hormones to effect my circulatory system?
Estrogen affects not only the contraction of your arteries and resting tone but your blood clotting. Which is why there are so many disclaimers about smoking when taking birth control pills, nicotine also works on the same system and makes a slight risk a significant risk.

What cells are filling or swelling?
Your breast has two main types of unique tissue, ducts and lobes. Lobes make milk, ducts transport it. As it turns out these are two large divisions of breast cancer but that's a topic for another day. Progesterone, if I remember correctly, causes the lobes to increase in size during pregnancy as well as when taking birth control, since many birth control pills are effectively tricking the body into thinking it is pregnant.

I have had a similar question about why the hormone surge of puberty/pregnancy can cause breast size to increase permanently but hormonal birth control only has a temporary effect; despite asking many doctors and various flavors of scientists over the years, nobody has given me a good answer.

Menopause does markedly change the density of breast tissue, however, as the hormone levels taper off sharply. But the effect on total volume seems to be less dramatic, and is very slow.
posted by hobo gitano de queretaro at 5:59 PM on June 8, 2013 [3 favorites]

The layman's explanation for the function of hormonal birth control is that it takes advantage of the mechanism that suspends ovulation during pregnancy, and it's generally explained as tricking the body into thinking it is pregnant. Is this the case or is it something completely different?

No, birth control pills do not "trick the body into thinking it is pregnant." Hormonal contraception suppresses ovulation through artificially stable hormone levels.
posted by Violet Hour at 6:21 PM on June 8, 2013

Best answer: That's the point of the pregnancy trick metaphor. As a metaphor, it is imperfect in explaining what is actually going on, but hits all the high points. Your hormone profile changes in a similar way to pregnancy, with similar effects.

The normal hormonal cycle is a sharp spike and drop off. Hormone levels during the early part of pregnancy are much more linear by comparison. The spike and drop off is what directly causes ovulation.

No, this explanation is not technically super-accurate because I have come to understand that when you attempt to be precise in explaining science, most people are lost in the tedium and the ones who care about the precise terminology were just going to look it up anyway.

Hormonal birth control prevents the spike by having stable levels, then at some/most include a period during the month where there is no hormone being taken, which allows the endometrial lining to shed and bleed. At a sufficiently high dose, you will not ovulate. At a lesser dose, your uterus will not allow an egg to implant.

Side note, some research shows that anywhere from a quarter up to half of fertilized eggs are miscarried very early on in the development of the embryo. And yes, in terms of hormone levels, that is a remarkably similar process to hormonal birth control. Genetic problems, chromosomal dysfunction etc. that early in a pregnancy are not fixable, and it doesn't even affect the menstrual cycle enough to be a concern. Whenever people talk about the sacred nature of pregnancy/birth control in its various forms is an abomination I wonder if they know that their definition of abortion is also a statistically inevitable consequence of having sex.

Human biology is always a lot messier than we pretend it is.
posted by hobo gitano de queretaro at 7:35 PM on June 8, 2013

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