Treating PCOS With the Contraceptive Pill: The Complete Guide
Although there is no one-stop cure for PCOS, the Combined Oral Contraceptive, commonly referred to as “the pill” or “birth control”, is one of the most common and effective methods for managing key symptoms of PCOS such as menstrual dysfunction and excess testosterone levels (acne and hair growth). The pill is a successful management strategy for most women with PCOS and can significantly reduce the risk of some cancers associated with PCOS. In this article, we explore what the pill is and how exactly it helps to treat PCOS. We will also look at the best type of pill for PCOS sufferers, who should use the pill and any side effects.
Contents
What is the Combined Oral Contraceptive
The Combined Oral Contraceptive pill, also known as “the pill”, is a medication containing external hormones used primarily for contraception, as well as other purposes. The contraceptive pill is used by more than 100 million women world-wide [source].
The contraceptive pill typically contains a combination of Estrogen and Progestin, two very important hormones in the regulation of the ovulation and menstrual cycle.
Progestins are a synthetic version of the natural hormone progesterone. They are chemically very similar however progestins are actually more powerful as they last longer in the body and are more easily used by the body. progestins cause most of their contraceptive benefits by preventing the production of Luteinising Hormone (LH), Follicle Stimulating Hormone (FSH), and ovulation. Progestins also cause cervical mucus to become hostile to sperm, they slow down the movement of eggs and reduce the fertilisation capacity of sperm. Estrogen in the pill functions primarily to regulate menstrual bleeding as well as inhibiting the formation of a dominant follicle [source].
For more information see: Ovulation, Menstruation and PCOS: What goes wrong?
There are many different types of progestins used in the contraceptive pill, however only a few estrogens are typically used. There are 3 main classes of progestins that are slightly different from each other. One class is produced from progesterone, one class is produced from testosterone, and the last class is produced from spironolactone [source].
A complete overview of the current formulations of contraceptive pill available on the market, sorted by generation. Showing the typical dosage of estrogen used and the different types of progestin available for each generation.
Individual formulations of the contraceptive pill consist of different types of progestins and different amounts of estrogen used. The various formulations are grouped into 4 different generations based on their design and when they were produced. The first and second generations typically contained more estrogen and had more severe metabolic side effects. The third generation used less estrogen, and had fewer metabolic side effects. The fourth generation also has fewer side effects and is also more strongly anti-androgenic [source]. The table above gives a complete overview of the current pill formulations and which generation they belong to.
How does the contraceptive pill help PCOS?
The contraceptive pill helps PCOS through two key mechanisms. Firstly, the pill helps to regulate the menstrual cycle, and secondly the pill reduces the ability of the ovaries to produce hormones [source].
We know that in PCOS, certain areas of the brain release too much Gonadotropin Releasing Hormone (GnRH). Excess levels of GnRH cause excess levels of LH and a high LH:FSH ratio. The unusual levels of LH and FSH cause the ovaries to produce high amounts of testosterone and cause ovulation to stop, which in turn stops menstruation. We also know that women with PCOS produce low levels of Sex Hormone Binding Globulin (SHBG), which is normally responsible for removing excess testosterone from circulation. Low levels of SHBG mean that not enough testosterone is removed from the blood stream, leading to symptoms such as acne and excess hair growth (hirsutism).
The estrogen and progestin in the contraceptive pill send signals to the brain to reduce the amount of GnRH being released. They do this by reducing the activity of Kisspeptin, which normally stimulates the brain to release GnRH. As less GnRH is being produced, less LH is released, meaning that LH and FSH levels are normalised. Normal LH:FSH levels mean that the ovaries do not overproduce testosterone, causing a reduction in excess testosterone around the body. Additionally, as excess testosterone also causes the brain to produce too much LH, reducing the excess testosterone actually leads to even more normal LH and FSH levels, causing a beneficial cycle [source].
In addition to its activity in the brain, the estrogen in the contraceptive pill causes the liver to start producing and releasing more SHBH. Increased levels of SHBG act like a sponge, soaking up and removing excess testosterone from the blood stream. These further decrease testosterone levels in women with PCOS, which also helps to reduce PCOS symptoms [source].
Some specific progestins used in the pill can have an anti-androgenic effect (they block testosterone from working), which can result in even further improvement in hair growth and acne in women with PCOS [source]. For that reason, a doctor may switch you to a pill formulation containing one of these progestins in order to maximise effectiveness if the changes you’ve seen have not been sufficient.
Through reduction in LH and increase in SHBG, the pill causes a drop in testosterone levels of approximately 50% in women with PCOS [source]. These changes occur over several weeks so a visual effect will not become apparent until much later, especially if the patient in question suffers from particularly high insulin resistance as their testosterone and SHBG levels will be more dependent on insulin than LH [source]. For this reason, women taking the pill to manage PCOS are encouraged to keep taking it for several months, even if they do not see any improvements at first [source].
An overview of how the contraceptive pill helps PCOS symptoms. The pill acts on the brain to normalise LH:FSH levels, leading to reduced testosterone production from the ovaries. The pill acts on the liver to increase SHBG production, which removes excess testosterone from circulation. Estrogen in the pill acts directly on the uterus to normalise menstrual cycles
Lastly, progestins and the regularisation of the menstrual cycle protect the endometrium (the lining of the uterus) against the constant, unopposed exposure to estrogen that it will often experience during PCOS. Without progestins sending a signal to the endometrium to begin shedding (menstruation), the constant growth and thickening of the endometrium may become a cancer risk [source]. Large studies have also shown that taking the pill for 5 years can significantly decrease the risk of developing ovarian and endometrial cancer with protection lasting for up to 30 years [source].
What type of contraceptive pill is best for PCOS?
There are many different formulations of contraceptive pills that can be prescribed, each with a different progestin or estrogen, in different ratios. As shown in the table above, there are three different classes of progestins based on what they are made from. There are much fewer different estrogens used.
Some contraceptive pills contain progestins that have an anti-androgenic effect. In other words, they more actively reduce the level of androgens, like testosterone, circulating around the body. Contraceptive pills containing anti-androgenic progestins have been shown to be more effective for reducing hair growth in women with PCOS, however the difference was only slight. For this reason, a doctor may suggest switching to an anti-androgenic contraceptive pill if the benefits of the pill have not been strong enough. The most commonly used anti androgenic progestins are Cyproterone acetate (CPA), and Drospirenone (DRSP) [source].
Similarly, some contraceptive pills contain progestins that are considered to have a lower risk of venous thromboembolism, otherwise known as blood clots. An increased risk of blood clots is one of the known side effects of the contraceptive pill, so for women who already have a high risk of blood clots, such as obese women, the Androgen Excess and PCOS Society suggest using a contraceptive pill that contains the lowest effective dose of estrogen and a progestin that is low risk for blood clots, such as Levonorgestrel (LNG) [source].
It should be noted that the more recent, third generation versions of the contraceptive pill have been proven to not have the unwanted metabolic side effects that were previously problems with the contraceptive pill. In fact, some studies have shown that they may even be beneficial for the lipid profile of the blood [source], even among obese and insulin resistant patients [source]! On the other hand, there is evidence to suggest that some new formulations of COC may still result in a slight increase in blood pressure, so caution and proper medical advice and regular review should always be used [source].
Side effects of the contraceptive pill
Despite their widespread usage, there are several negative side effects that have been associated with usage of the oral contraceptive pill, such as elevated cholesterol, nausea, breast tenderness, headaches, mood changes, and cervical cancer risk. In general, the side effects will depend on the exact type of formulation of the pill used (e.g. type of progestin, amount of estrogen or progestin).
Certain formulations, commonly referred to as the third generation versions of the pill, have been proven to show fewer side effects, particularly metabolic side effects, and may even be beneficial for things like cholesterol levels. Third generation contraceptive pills are characterised by low doses of estrogen and powerful progestins derived from testosterone [source].
Oral contraceptives have been associated with deteriorations in blood lipid profile (the different fats, such as cholesterol, found in the blood), however this has not been associated with any significant changes in other metabolic issues or indicators, such as BMI, blood glucose levels, insulin levels, blood pressure or insulin resistance [paper]. Some studies have shown that some particular formulations of the oral contraceptive pill can increase total cholesterol levels in women with PCOS, which is something to be considered by a doctor when prescribing the contraceptive pill, especially if the patient already suffers from non-favourable cholesterol levels [source]. On the other hand, a large number of studies have indicated that most oral contraceptive formulations actually cause a favourable change in levels of HDL cholesterol (the beneficial kind of cholesterol) [source].
Around 10% of women taking the contraceptive pill report symptoms of nausea, breast tenderness, and headaches, however these side effects are becoming less common as formulations improve [source]. Other side effects of the contraceptive pill are mood changes and unscheduled bleeding. These symptoms typically stop within the first 3-4 months however they may be severe enough to require the patient to stop taking the contraceptive pill before the side effects can pass [source].
The use of contraceptive pills has been associated with an increased risk of cervical cancer. A very large study reviewing 24 different long term studies from around the world has shown that the use of current contraceptive pulls for more than 5 years approximately doubles the risk of cervical cancer compared to women that never use the contraceptive pill. This risk begins declining as soon as the patient no longer takes the pill and will reach normal levels of risk within 10 years [source]. On the other hand, taking the contraceptive pill for 5 years significantly decreases the risk of ovarian and endometrial cancer. In fact, 5 years of contraceptive pill use provided protection against ovarian cancer for over 30 years [source]! In general, because women with PCOS are already considered high risk for ovarian and endometrial cancer the use of the pill is still recommended as the benefits of its protection against ovarian and endometrial cancer outweigh the cost of the increased cervical cancer risk. As with all medical decisions, this should be decided on an individual basis and is something to talk to your doctor about.
Venous thromboembolism is the term given to the development of blood clots, which can lead to serious events such as heart attacks or strokes. Women with PCOS already have an increased risk of developing blood clots. The average rate of blood clot development in women is around 5 – 10 per 10,000 women, per year [source]. For women taking the contraceptive pill this increases to 8-10 per 10,000 women, per year [source]. Although this is still much lower than the increase in risk whilst pregnant, it is still a significant increase in risk. It appears that the risk of developing blood clots changes with the dose of estrogen and the type of progestin used in the contraceptive pill [source]. A lower estrogen dose carries less risk, which is why third generation pill formulations are often preferred as they contain around half the estrogen of first and second generation pills. Cyproterone acetate is a type of progestin that is considered much higher risk for blood clot development and should generally be avoided by women with PCOS or any other blood clot risk factor (such as smoking or obesity). Desogestrel, Drospirenone, and Gestodene are also all progestins that have been associated with increased risk of blood clots [source]. In general, the risk of blood clot development is very low in young, healthy women with or without PCOS, so the contraceptive pill can be prescribed, however this is again something that is best decided on an individual basis by the doctor, who will consider other lifestyle risk factors such as smoking or family history [source].
Obesity and the contraceptive pill
For women who are considered obese or overweight, extra caution should be taken by the doctor when prescribing the combined oral contraceptive to manage the symptoms of PCOS. The reason for this is that as BMI (body mass index) exceeds 30, the risk of developing venous thromboembolism, otherwise known as blood clots. Compared to non-obese women, obese women appear to have double the risk of developing blood clots when taking the contraceptive pill [source]. However, this risk is most profound in women who are perimenopausal. Perimenopause is the term for the period of changes that lead up to menopause, which can last for several years. Perimenopause can begin as early as the late-thirties or as late as the early-fifties and can last from 4-8 years. For obese women who are not perimenopausal, the use of the pill is still recommended as the benefits are generally believed to heavily outweigh the risks.
For a long time, there was a lot of speculation about whether the contraceptive pill caused weight gain. Long term studies have strongly concluded that there is no significant difference in bodyweight gain after half a year of contraceptive pill usage, although these studies were in women without PCOS [source]. Similarly, a study lasting 20 years has shown that there is no evidence for increased weight gain for women taking the contraceptive pill [source]
The majority of evidence agrees that obesity does not change the efficacy of the contraceptive pill for managing the symptoms of PCOS. Some studies have shown that the contraceptive pill can negatively affect the ability of the body to metabolise carbohydrates and fats, however not to an extent that is clinically meaningful [source]. Even so, for women with PCOS, changes in metabolism should be followed closely when taking the pill and different formulations should be considered if necessary.
For more information on PCOS and obesity, check out: PCOS, Insulin and Obesity: Everything you need to know
Who should use the contraceptive pill?
As we’ve seen above, the contraceptive pill is not a suitable management tool for everybody with PCOS, despite its many benefits. So, who can and can’t use the contraceptive pill? This is something that has to be decided on an individual basis by your doctor. Progress and side effects should be closely monitored in follow-up appointments, so do not skip those. Obviously, the contraceptive pill should not be used to manage the symptoms of PCOS if you are trying to conceive!
Even though this decision is made on an individual basis, there are still some guidelines for who should use the contraceptive pill. The World Health Organisation has published a list of secondary conditions that means the patient should not use the contraceptive pill [source]. The list of risk factors includes:
- Presence or history of arterial or venous thrombosis (blood clots).
- History of migraines
- Known disposition for blood clot development.
- Presence of heart disease.
- Severely high blood pressure.
- Presence of Type II Diabetes.
- Presence or history of liver disease.
- Presence or history of liver tumours.
- Known, or suspected malignancies of the genitals or breasts.
- Endometrial hyperplasia (uncontrolled growth).
- Undiagnosed vaginal bleeding.
- Jaundice of pregnancy or jaundice from prior pill use.
- Known or suspected pregnancy.
Before the pill is prescribed to mange PCOS, the doctor should carry out a series of assessments. Starting with a diagnosis of PCOS, lifestyle modifications should be trialled and assessed. Following this, the doctor will assess age, medical history, current medication, and family history to uncover risk factors. Next the doctor will measure blood pressure, body mass index, waist circumference and hirsutism (hair growth) score. Lastly, the doctor will analyse fasting blood glucose levels, lipid profile, liver function, beta-hCG, and insulin responsiveness. With all of this information, the doctor will decide if the patient carries any risk factors that would make prescribing the pill too dangerous or will affect which formulation of the pill is prescribed [source].
