Combined pills (Combined oral contraceptive pills)
Combined contraceptive pills, the most commonly prescribed pill, contain two versions of naturally occurring female hormones: estrogen and progestin. There are also different versions of these synthetic hormones, which surround generational pill changes over the years, and some affect women in different ways.
Each month, levels of estrogen and progestin rise and fall naturally which impacts how and when the female body prepares for pregnancy. Ovulation occurs, for example, and the uterus lining thickens to create a safe environment to receive a fertilized egg.
So, how do combined pills work? When you take combined contraceptive pills, natural levels of these hormones are altered. In doing so, the way in which the body prepares for pregnancy changes. Eggs don’t get released, vaginal mucus thickens which makes it difficult for sperm to pass through the cervix and the uterus lining remains thin, which means in the (now very unlikely) event an egg does get fertilized, it will have a tricky time implanting itself in the uterus where it would normally grow.
Typically, the combined pill comes in packs of 28, with 21 pills containing hormones and 7 “inactive” spacer pills that don’t have any hormones. It’s also possible to skip the week of spacer pills and go straight into a new packet, which is called “stacking.” Certain other combined contraceptive pills are taken for 24 days, followed by only four days of taking placebo pills.
Combined pills are over 99% effective when used perfectly. (Perfectly meaning you never forget to take a pill and always take them at the time you’re supposed to.)
Common side effects associated with the combined pill can include nausea, stomach ache, putting on weight, headaches, depressive moods or mood swings and sore or painful breasts. However, because certain combined pill brands contain different versions of female hormones, depending on their generation, switching pills can sometimes help reduce certain side effects.
Pros and cons of the combined pill
Advantages of the combined pill:
- You’re in control, you can start and stop using the method whenever it suits you
- Won’t interrupt sex in the same way a condom might
- Can make periods more regular, lighter or less painful
- Reduces the risk of certain types of cancer, including cervical and ovarian
- Can reduce premenstrual symptoms
- Can reduce acne
- May reduce the chance of pelvic inflammatory disease
- May reduce the risk of ovarian cysts and fibroids
Disadvantages of the combined pill:
- May cause side effects that clear up over time, including headaches, feeling sick, tender breasts and mood swings.
- May increase blood pressure for some women
- Doesn’t protect against STIs
Spotting is common for the first few months of using the pill
- Has been linked with a small but increased risk of blood clots and breast cancer.
Mini pills (Progestin-only pills)
Mini pills offer birth control without estrogen. They're also known as progestin-only pills (POP). These might be better for women who experience estrogenic side effects when using the combined pill. They’re also a safer choice for women who shouldn’t take the combined pill due to their age, smoking habits or medical conditions.
Traditional mini pills prevent pregnancy by thickening cervical mucus, which stops sperm from reaching an egg. Mini pills which contain desogestrel as their active ingredient can also prevent ovulation from occurring.
Like combined pills, mini pills are over 99% effective when taken perfectly. When taken “typically” their effectiveness drops to around 91%. This means nine out of every 100 women who used the mini pill typically will become pregnant.
You have to take the mini pill every day without breaks in between packs. If you’re over the age of 35 and smoke, it’s safe for you to use the mini pill.
Common side effects associated with the progestin-only pill include feeling sick, headaches, loss of libido, tender breasts, breast enlargement, mood swings, dizziness, fatigue, bleeding between periods and skipped periods.
Pros and cons of the mini pill
Advantages of the mini pill include:
- Doesn’t interrupt sex the same way a condom might
- Can be taken postnatally and also when breastfeeding
- Safe to use if you cannot take the estrogen hormone
- You can use it at any age
- Safer for smokers than the combined pill
- Can make periods less frequent, lighter or even stop
Disadvantages of the mini pill include:
- Your periods may change and become irregular
- Doesn’t protect against sexually transmitted infections
- You need to remember to take it daily and at a similar time each day (though this is dependant on the brand)
- Certain medications can reduce mini pill effectiveness.