Drospirenone & Ethinyl Estradiol (Yaz) 101: How it Works, Side Effects and Interactions

Yaz is a widely used birth control pill on the market. Made from a combination of drospirenone and ethinyl estradiol, Yaz is a form of combined oral contraceptive that’s designed to prevent pregnancy.

If you’ve looked into using oral birth control, Yaz is probably one of several brands you’ve come across. Used properly, Yaz works well as a birth control pill, with a good track record and only a few side effects to be aware of.

Like many other combined oral contraceptives, Yaz also works as an acne treatment thanks to its ability to suppress your body’s production of androgen hormones.

Sound confusing? Not to worry. Below, we’ve explained exactly how Yaz and other birth control pills that combine drospirenone and ethinyl estradiol work, as well as the potential side effects to be aware of if you start using Yaz for birth control.

Like other oral birth control, Yaz uses a combination of different female sex hormones to prevent pregnancy.

Yaz contains two different hormones. The first hormone is drospirenone, a progestin that works by targeting your body’s progesterone receptors. The second hormone is ethinyl estradiol, an estrogenic hormone that’s used both in Yaz and a range of other birth control pills.

Birth control pills that use this combination of hormones are known as “estrogen and progestin” contraceptives, or “combined oral contraceptives.”

These two hormones work together to prevent pregnancy. The process by which Yaz works is surprisingly simple: by increasing your body’s levels of drospirenone and ethinyl estradiol, Yaz can stop your ovaries from releasing eggs (a process known as ovulation).

The combination of drospirenone and ethinyl estradiol in Yaz also changes the lining of your uterus and the mucus surrounding your cervix, making it more difficult for sperm to enter into your uterus and cause pregnancy.

In short, birth control pills like Yaz prevent pregnancy from two angles: by preventing ovulation while also making it physically more difficult for sperm to pass through your cervix.

Compared to the traditional 21:7 active:inactive ratio used by other birth control pills, combined birth control pills like Yaz keep your body’s hormone levels more steady, helping you make side effects less intense and more manageable.

Used according to the instructions, Yaz is very effective as a form of birth control. In a clinical trial with observation from researchers, the combination of drospirenone and ethinyl estradiol in Yaz is more than 99% effective at preventing pregnancy.

Of course, real life is never quite as precise and perfect as a clinical study. Because of this, Yaz is about 91% effective as a form of birth control. 

This “real life” effectiveness rate includes things like missing a pill and accidentally using Yaz with other medication that makes it less effective.

Now, it’s important to understand what this percentage means. 92% effective does not mean that you risk getting pregnant eight times out of every 100 times you have sex. Instead, it’s an annual likelihood of pregnancy while using Yaz under normal conditions.

For example, the 92% effectiveness statistic for Yaz means that fewer than eight out of 100 women will get pregnant every year while using the medication in “real life” conditions.

If you’re extra careful with your birth control usage, don’t take any other medication that could interfere with its effectiveness and never miss a pill, your risk of pregnancy can decrease even further towards the 99% effectiveness observed in studies.

Although the main purpose of Yaz is to prevent pregnancy, it also works well as a treatment for acne. In fact, the FDA has approved Yaz as one of three birth control pills that can be used for treating hormonal acne outbreaks.

Acne develops because of fluctuations in your levels of androgen hormones. When your body produces too much testosterone (a powerful androgen that’s present in men and women), the amount of natural oils called sebum secreted by your pores can increase.

This leads to blockages, which in turn can lead to acne outbreaks. If these blockages become infected with bacteria, they can become inflamed and painful, potentially leading to cystic acne and other serious skin issues.

Used as an acne treatment, drospirenone/ethinyl estradiol birth control pills like Yaz reduce your body’s production of testosterone. With a lower average testosterone level, your body secretes less oil onto the skin, resulting in fewer clogged pores and acne lesions.

Our guide to hormonal acne explains the role androgens play in acne in more detail, along with other effective treatments.

Used alone, Yaz is normally effective at treating acne. However, for severe acne, dermatologists might prescribe a drospirenone/ethinyl estradiol birth control pill like Yaz in combination with an antibiotic such as clindamycin and a topical retinoid such as tretinoin.

The most obvious benefit of drospirenone/ethinyl estradiol birth control like Yaz is that, if used properly, it prevents pregnancy.

Yaz also has several other benefits. As we mentioned above, it’s a fairly effective treatment for hormonal acne. 

It’s also used to treat premenstrual dysphoric disorder (PMDD), a severe form of premenstrual pain, fatigue and emotional distress that affects up to eight percent of women.

Drospirenone/ethinyl estradiol birth control pills such as Yaz can also give you a lighter, more regular period. Many women notice a shorter, easier period while using Yaz than before using hormonal birth control.

Because Yaz affects your body’s estrogen, progestin and androgen levels, it can also lighten and ease many of the unpleasant symptoms that accompany your period. Many women notice less bloating and weight gain during their period after they start using Yaz.

Drospirenone/ethinyl estradiol birth control like Yaz can also manage period pain, making your period more tolerable if you’re prone to cramping and muscular discomfort in the days leading up to your period.

From an acne treatment perspective, Yaz and other drospirenone/ethinyl estradiol birth control pills have numerous benefits. A study from 2011 shows that the drospirenone/ethinyl estradiol combination produces a measurable reduction in acne lesions in women aged 14 to 45.

Other studies show similar results. A 2013 study of drospirenone/ethinyl estradiol as a treatment for truncal acne shows that Yaz and other drospirenone/ethinyl estradiol birth control pills are as effective for treating acne on the chest and back.

Drospirenone/ethinyl estradiol birth control like Yaz is very easy to use. For birth control or acne prevention, take one pill daily. It’s most effective to take Yaz at the same time every day to keep your hormone levels steady and consistent.

Most healthcare providers advise their patients to start using Yaz at the beginning of their menstrual cycle, or on the first Sunday after starting the menstrual cycle. Follow your healthcare provider’s instructions when you start Yaz to make sure you have a predictable, simple usage regimen.

Yaz and other drospirenone/ethinyl estradiol birth control pills are divided into active does and inactive dose pills. If you miss an active does, take two pills on the day that you notice you’ve missed the previous dose.

If you miss two active pills in a row, take two pills per day for the next two days. After this, you can go back to using the standard one pill daily dose.

If you miss three active pills in a row, or miss two active pills in a row during the third week, it’s best to throw out the pack and start a new pack of Yaz or other drospirenone/ethinyl estradiol birth control on the same day.

If you miss an inactive dose pill, throw the missed out away and continue taking the inactive pills as normal. Missing more than two pills in a row can affect your period. You might not get a period on that month, or your period could be delayed. 

If you miss your period for two months in a row, you’ll need to call your healthcare provider as there could potentially be a pregnancy risk. After you’ve missed a dose, it’s important to use another form of contraception, such as condoms, for at least one week while you continue using your birth control medication.

When using Yaz or other drospirenone/ethinyl estradiol birth control pills, follow the instructions on the prescription label or medication packaging.

Drospirenone/ethinyl estradiol birth control pills such as Yaz have a range of side effects, from common, minor side effects to potentially serious side effects that can require attention from a healthcare provider. 

The most common side effects of drospirenone/ethinyl estradiol birth control are:

Weight gain

Yaz and other drospirenone/ethinyl estradiol birth control may cause weight gain in some women due to water retention and changes to your appetite. 

This weight gain is usually the result of water retention and often reverses if/when you discontinue the medication.

Nausea and vomiting 

Many women experience some degree of nausea when using Yaz and other drospirenone/ethinyl estradiol birth control pills. 

This is often temporary and typically lessens during the first two months of use.

Mood changes, irritability and headache

Some women report mood changes and irritability after starting Yaz. Some Yaz users have also reported headaches after they started using the medication, often coinciding with menstruation.

Breast tenderness

The hormones in Yaz can cause some increase in the tenderness of your breasts. Some women also experience mild breast pain while using Yaz due to the effects of the drospirenone and ethinyl estradiol on breast tissue.

Increased breast size

Yaz and other hormonal birth control pills can affect your breast tissue and cause a temporary increase in the size of your breasts. 

Most women notice a mild increase in breast size, or no increase at all, using hormonal birth control.

Vaginal bleeding/spotting

It’s quite common to experience minor vaginal bleeding or spotting while using Yaz and other birth control pills. This usually occurs during the first two months of use and typically resolves itself over time.

Yaz also has several less common, potentially more serious side effects. If you experience any of the side effects listed below, it’s important to stop taking drospirenone/ethinyl estradiol birth control and contact your healthcare provider for assistance:

High blood pressure

Combined oral contraceptives such as Yaz can potentially raise your blood pressure. If you experience chest pain, shortness of breast, blurred vision, difficulty breathing or severe headaches, contact your healthcare provider.

Sleep problems, fatigue and tiredness

These symptoms are all potential side effects of hormonal birth control pills such as Yaz. They often become less severe after the first two to three months of use but deserve medical attention if they affect your life.

Liver problems such as jaundice and dark urine 

Although uncommon, it’s possible for hormonal birth control pills such as Yaz to affect your liver. If you notice any signs of liver damage, such as tiredness, dark urine, clay-colored stools or yellowing of the skin and/or eyes, contact your healthcare provider immediately.

Blood clots

In rare cases, oral contraceptives such as Yaz can cause blood clots to develop. 

If you notice a stabbing pain in your chest, sudden loss of vision, shortness of breath or coughing up blood, contact your healthcare provider immediately.

A blood clot can also form in your leg and other places. If you develop any redness, warmth, or swelling, seek medical attention immediately. 

Stroke

Although rare, Yaz and other drospirenone/ethinyl estradiol birth control pills can increase your risk of experiencing a stroke. If you notice a rapid-onset severe headache, sudden weakness or numbness on one side of the body, vision problems, slurred speech or issues balancing, seek immediate medical assistance.

Your risk of experiencing side effects from Yaz can increase if you smoke, are over the age of 35, or use other medications at the same time as drospirenone/ethinyl estradiol birth control. 

Speak to your healthcare provider about any other medications you use before you begin using drospirenone/ethinyl estradiol birth control.

Cigarette smoking significantly increases your risk of experiencing cardiovascular issues such as high blood pressure, heart attacks and strokes while taking drospirenone/ethinyl estradiol birth control such as Yaz.

If you smoke, it’s essential that you talk to your healthcare provider before considering drospirenone/ethinyl estradiol birth control medications such as Yaz. 

The risk of cardiovascular events is particularly high in women aged 35 and up who smoke.

Drospirenone/ethinyl estradiol birth control pills can interact with a variety of other medications, including antibiotics rifampin and rifabutin. 

These interactions can potentially increase your risk of experiencing side effects or make the birth control less effective at preventing pregnancy.

RXList has a complete list of drospirenone/ethinyl estradiol birth control drug interactions, with detailed information on the specific medications to avoid while taking Yaz or similar drugs for birth control.

If you take other medications, it’s important to inform your healthcare provider before you start using Yaz or similar drospirenone/ethinyl estradiol birth control. 

If necessary, your healthcare provider might recommend an alternative form of birth control that’s less likely to interact with your existing medication.

Drospirenone/ethinyl estradiol birth control pills such as Yaz are one of several combined oral contraceptives available. 

They’re also one of the three birth control pills approved by the FDA for treating and preventing acne.