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How effective is the mini pill?

There are many different hormonal birth control methods on the market. When talking about birth control pills, most people tend to mean the combination pill. Today we’ll take a closer look at another kind of birth control pill called the mini pill, sometimes referred to as progestin-only pills or POPs.

What is the mini pill?

The mini pill is a kind of birth control pill that only contains progestin, a synthetic version of the hormone progesterone. Different mini pill brands can have different doses of progestin, but they work in the same way.

The mini pill prevents pregnancy in a number of ways. It makes your cervical mucus thicker so that the sperm are not able to reach the egg. The pill also makes the lining of the uterus thinner so that implantation doesn’t happen. It can also stop you from ovulating or cause ovulation to become irregular.

You can start taking the mini pill at any time during your cycle, but how soon you are protected from pregnancy depends on when you start taking it. If you start the mini pill during the first five days of your cycle (counting from the first day of your period), you are protected from pregnancy right away. If you start on any other day of your cycle, it takes two days (48 hours) for the mini pill to become effective. If you choose to have sex during these two days, you’ll need to use another form of protection, for example, a condom, to prevent pregnancy. If you have short cycles, you should also use additional protection during the first two days on the mini pill, regardless of when you start taking it.

What is the difference between the mini pill and the combination pill?

The main difference between the mini pill and the combination pill is that the mini pill only contains progestin, while the combination pill contains doses of both estrogen and progestin.

While both the mini pill and the combination pill make your cervical mucus thicker so that sperm will not survive, the combination pill will also always stop your ovulation. The mini pill can stop ovulation too, but it doesn’t happen for everyone – some will still ovulate but ovulation usually becomes more irregular.

Both types the mini pill and the combination pill require you to take a pill daily. Some types of mini pills have to be taken within the same three hours every day to be effective, while others need to be taken within the same 12 hours. Combination pills are usually a bit more flexible and usually only need to be taken within a 12-hour window, but you should always check the instructions on your specific pill packet.

What is progestin-only birth control?

Progestin-only birth control methods are a selection of contraceptive methods that instead of containing both synthetic progesterone and estrogen, contain only synthetic progesterone. There’s a variety of reasons why people may choose these methods, such as health or lifestyle reasons. 

For example, individuals who are diagnosed with a certain kind of migraine or those who have a high risk of developing blood clots may be medically advised from taking the combined contraceptive pill.

For these individuals, a progestin-only option (such as the mini pill) offers an alternative form of hormonal contraception. Other progestin-only birth control options include the birth control implant and injection

Mini pill effectiveness

When talking about birth control birth control effectiveness, we use the terms perfect use and typical use. Perfect use means that the method is used exactly according to the instructions, while typical use describes how the method is used in real life – including when it’s not used according to the instructions.

The mini pill is 99% effective with perfect use. With typical use, the mini pill is 93% effective, meaning that 7 out of 100 of those who use this method become pregnant during one year of use. Typical use of the mini pill includes if you forget to take a pill or don’t take the pill at the same time each day. 

Certain medications can also make the mini pill less effective. The instructions that come in your pill packet should have information about this, but it’s always good to check with your healthcare provider if you take medication while on the mini pill.

It’s also important to keep in mind that the mini pill does not protect against STIs.

What happens if I forget a pill?

You have to take your pill at the same time every day for the mini pill to be effective, but we all know that mistakes can happen so it’s good to be prepared for what you should do if you forget one day.

If you happen to miss a pill or if you’re more than three hours late taking your pill for the day (or 12 hours late depending on the brand you’re using), you’re no longer protected from pregnancy, so you’ll need to use additional protection if you have vaginal sex. Exactly what to do when missing a pill can differ from one mini pill brand to another, so make sure to check the instructions for the kind that you’re using. 

If you’ve had sex in the two days after you miss a pill you should also consider using emergency birth control. Your healthcare provider will be able to help you decide which method would work best for your situation. 

To avoid forgetting to take the pill, it can be helpful to take it at a time of day when you have a set routine, for example before going to bed or brushing your teeth. If you struggle to remember or just have a varying schedule, you can also set an alarm to help remind you. 

Do you still get your period on the mini pill?

This varies from person to person. Most mini pill brands come in 28-pill packets where all the pills contain hormones, so you don’t take a break between packets and there are no placebo pills (which is usually the case with the combination pill). Since all the pills contain hormones, you can’t actively skip bleeding by taking mini pills, as you can with the combination pill.

While some people don’t bleed at all while on the mini pill, most will still experience some bleeding – although it’s common for the bleeding to become irregular and be less heavy. It’s also common to experience spotting on the mini pill.

Do you get your period on the mini pill while breastfeeding?

Mini pills are safe to use while breastfeeding and you can start taking them right away after giving birth. The mini pill doesn't affect the amount of milk you produce (which can be the case with the combination pill) and it doesn't affect your baby. 

Since you can ovulate while on the mini pill, you might get your period back if you’re using this method while breastfeeding, assuming that your ovulation has returned after you’ve given birth – but it can take a while for ovulation to happen after a pregnancy. You may also experience some lighter or irregular bleeding caused by hormonal changes. 

What are the side effects of the mini pill?

As with other hormonal birth control methods, you might experience side effects. Some common side effects of the mini pill include:

  • Spotting or bleeding between periods
  • Sore breasts
  • Acne
  • Nausea
  • Headaches
  • Changed sex drive
  • Mood changes
  • Ovarian cysts

It is common to have more side effects in the beginning when you start to use the mini pill, and they can go away or lessen with time. However, if you are concerned about side effects or not feeling well while on the pill, it’s always good to talk with your healthcare provider about what options you have. You don’t have to put up with birth control that makes you feel unwell, and there are other options out there that might work better for you.

There is also research looking into a possible link between the mini pill and breast cancer and at this time, there is not enough evidence to rule out an increased risk of breast cancer associated with the mini pill. A recent study found a small increased risk of breast cancer for those using the mini pill, similar to what has been found for the combination pill. This risk is likely to go away with time if you stop taking the pill.

Interested in going hormone-free?

Thinking about switching to birth control with low or no hormones? At Natural Cycles, we believe that birth control is a very personal choice and only you can decide which method is right for you. We’ve created the world’s first FDA Cleared birth control app, offering one more hormone-free option! 

If you’re looking to switch birth control or you’re curious about non-hormonal options, why not check out Natural Cycles to see if it would be a good fit for you? 

Did you enjoy reading this article?

Are you ready to go hormone-free with Natural Cycles?

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Written By

Freya Eriksson

With more than three years of experience in the field, Freya Eriksson specializes in writing about the latest research into fertility and reproductive health. She is passionate about shining a light on under-researched topics such as contraception and planning pregnancy. Freya holds a Master's degree in Linguistics and lives in Stockholm, Sweden.

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Scientifically Reviewed

Jack Pearson

Dr. Jack Pearson is a previously HCPC registered Embryologist with a PhD in reproductive medicine. Prior to joining Natural Cycles leading Medical Affairs, he worked for more than 10 years in a clinical setting working at some of the busiest fertility clinics in the UK. Today he spends most of his time working with experts at the world’s leading institutions to carry out important research with the vision to further the field of female health. He earned his PhD from the University of Sheffield specializing in Sperm Metabolism and currently lives in London.

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