Our most popular contraceptives: IUS v combination pill

by Sophie King · March 4, 2021

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Reviewed by Dr. Melanie Davis-Hall on September 16, 2021

can you get pregnant on the pill
Rated two of the most popular birth control methods by The Lowdown reviewers, it seems only fair that we bring you an informative piece comparing the IUS - or intrauterine system - and the combined pill. By doing so, we hope you grasp a better understanding on what might be the best one for you and your body.

Choosing the right contraception for you is an important one and a decision, that we are sure you are aware of by now, can often take a while to figure out.

By highlighting how each method works, what the advantages and disadvantages are for both, and what our reviewers say, we hope it helps you get to the stage where you have found your perfect match that little bit quicker.

In this piece, The Lowdown brings you information, comparisons and reviews of the IUS and the combination pill, as our users’ favourites.

Of course, there are many different brands of each, and symptoms and experiences will vary, but we hope that this article brings you a generic round up of both to help you make a better decision on which may be the best one for you.


At a glance: the advantages and disadvantages

The IUS – Advantages

  • It is more than 99% effective at preventing pregnancy. This means that over the course of 1 year, less than 1 in 100 women will get pregnant whilst using it.
  • Once it is in, you do not have to do anything until it needs to be replaced
  • It works for three or five years, depending on the brand.
  • Periods usually become less painful, lighter and shorter and may become less frequent or stop altogether.
  • Your fertility returns to what is normal for you as soon as it is removed – meaning it is possible to get pregnant straight away.
  • It is not affected by other medicines.
  • It might be a good option if you cannot take the hormone oestrogen
  • The Mirena IUS is also licensed for use as part of hormone replacement therapy (HRT), which is used in the management of menopausal symptoms.


The Combined Pill – Advantages

  • With perfect use (using the method correctly all the time) the pill is over 99% effective, and with typical use it is around 91% effective
  • It usually makes your periods regular, lighter and less painful
  • You have the choice to skip a monthly bleed – ask your doctor or nurse about continuous pill taking
  • It can improve acne
  • It can reduce symptoms of premenstrual syndrome (PMS)
  • It can help manage symptoms associated with polycystic ovary syndrome (PCOS), including acne, abnormal hair growth and irregular or no periods
  • It can reduce the risk of recurrent endometriosis after surgery
  • It reduces the risk of endometrial, ovarian and colorectal cancer
  • You have control over when to stop taking it (although it’s worth discussing with your healthcare professional if you wish to avoid pregnancy or switch methods)
  • As soon as you stop taking it your fertility will return to what is normal for you.


The IUS – Disadvantages

  • For the IUS to be fitted you will need an appointment with a doctor or nurse and will need to have a pelvic examination
  • There is a small risk of infection when it is fitted and you may be advised to have a test for STIs beforehand
  • There is a very small risk of damage to the womb when your IUS is fitted
  • There is a small chance the IUS can move or be pushed out of the womb. After fitting, you will be taught how to check it is in place
  • In the rare chance you do become pregnant while using the IUS, there is a small risk of an ectopic pregnancy (a pregnancy outside of the womb)
  • You may get period type pain and some light bleeding after it is fitted, which should improve. 
  • Some women experience irregular bleeding or ‘spotting’, especially in the first few months which usually settles. 
  • Some women experience headaches, acne and breast tenderness which usually improve after the first few months. Some women experience changes in libido and mood. 
  • Some women may develop small fluid filled cysts on their ovaries. These are usually harmless and resolve without treatment
  • You will need to have an appointment with a doctor or nurse for it to be removed
  • The IUS does not protect you from sexually transmitted infections (STIs), so for this you need to use condoms as well.


The Combined Pill – Disadvantages

  • You must remember to take it every day, preferably at the same time
  • Missing pills, vomiting or severe diarrhoea can make it less effective
  • Some medicines can interact with the pill, meaning it might not work properly. If you are taking other medicines then you should check this with your doctor or nurse
  • Irregular bleeding and spotting is common in the first few months of using the pill, but this usually settles
  • Some women experience headaches, breast tenderness or nausea which usually improve after the first few months. Some women experience changes in libido and mood. 
  • It can increase blood pressure
  • There is a slight increased risk of developing a blood clot when taking the combined pill. This means a blood clot in the leg or lung, or a heart attack or stroke. These risks are very small and the pill is considered safe in most healthy women. 
  • The pill can slightly increase the risk of developing breast and cervical cancer. This reduces with time after stopping the pill
  • The pill does not protect you from sexually transmitted infections (STIs) so for this you need to use condoms as well.

Talk to one of our friendly doctors

The stats

What do our reviewers say?

One difficult thing about contraception is that everyone can react differently to the same product, meaning it is tricky to gauge a good idea on what might be best for you. Here, we have collated user feedback so that you hopefully have a better idea of what the IUS and combined pill might mean for you.

For the IUS, the most common immediate side effect was womb cramps, with around 65% of reviewers reporting pain. Of those, 22% said they had cramps a bit, 19% said quite a bit and 14% had them a great deal. For the combined pill, the most common immediate side effect was tender breasts with 60% of reviewers reporting a change. Of those, 22% reported a bit of a change, 18% quite a bit and nine per cent said there was a great deal of change.

In terms of after affects or once they had been taking the pill for a while, spots and acne was the most common change for the combined pill and womb cramps continued to be a symptom for the IUS. Most respondents said the pill only affected their skin a bit, while just 2% said affected it a great deal.

For the IUS, of the 90% who said they had womb cramps after the coil had settle, 30% said their cramps change a bit, while 20% said there was a great deal of change.

More than half (52%) of reviewers said the IUS stopped their period completely, while 18% said their periods became irregular and 16% said they became lighter. For the combined pill, the majority (50%) said their bleeds were lighter, with 16% reporting no change and 10% saying they were heavier.


Kyleena – ‘I feel like a different person’

“I came off of Gederal 30/150 and got the hormonal coil, and can’t begin to explain how much better I feel, not to sound cliché but feel like a different person, I used to have anxiety over things I knew I sorta shouldn’t of had anxiety over and would wake up in the most foul mood for no reason whatsoever and now both those two things have completely gone. I also haven’t had a period yet and have had it for 4 months, only just a few random spots of blood on and off. My skin has also cleared up massively where as on the pill I was coming out in huge boil-like spots. The insertion is ever so slightly painful and I had bad cramps for about 2 days but now they’re gone too. I also noticed a huge difference in how hungry I’d get. On the pill I’d eat a big meal and fed hungry still so would really want to eat more and often did, however since being on the coil I’ve noticed that doesn’t happen anymore, like I’m only really hungry when I know I should be.”

Mirena – ‘I would highly recommend’

“I have used the coil for best part of 20 years after my now 20 year old son was born. I would highly recommend, after trying the pill before this, hated that!”

Combined pill

Rigevidon – ‘Constantly in a bad mood’

I have been taking this for a few weeks now and have already had a bad experience. I am constantly in a bad mood and my discharge has gotten much worse and my breasts are constantly tender.

Rigevidon – ‘Made me throw up’

“I was on this pill for 4 days and had to come off because it constantly made me throw up and I wasn’t able to keep any food down and only limited water. The day after I stopped taking this pill I was fine again.”

Millinette – ‘The best yet’

“I have been on 4 type of birth control before this and this is the best yet. The effects I’ve experienced are minimal when on this pill. I in the first two weeks of taking it experienced some nausea and dizziness but nothing too extreme. I had a lot of problems previously with sex drive, headache and mood swings on other pills. This pill is 10/10 IMO.”

Check our reviews

The IUS – how it works

The IUS – or the hormonal coil – is a small plastic device that is inserted into your womb by a doctor or nurse. It prevents pregnancy by releasing a synthetic form of the hormone progestogen, similar to the one produced by the ovaries. This makes the fluid at the cervix (neck of the womb) thicker and therefore harder for sperm to get through. It also thins the lining of the womb so a fertilised egg can’t implant and in some women stops them ovulating.

The insertion is a procedure that requires a pelvic exam and can be an uncomfortable procedure. Depending on the type of IUS, once it is in it can last for up to five years.

It can be fitted at any time during your menstrual cycle if you are definitely not pregnant. If fitted within the first 7 days of your cycle, you will be protected against pregnancy right away. If fitted at any other time, it is advised you use another form of contraception, such as condoms, for the next seven days.

Most people with a uterus can use an IUS, including those who have never been pregnant. An IUS can also be fitted from four weeks after giving birth.

The combined pill – how it works

The combined pill, the one usually referred to as just ‘the pill’, contains oestrogen and progestogen, similar to the hormones produced by the ovaries. The combined pill prevents pregnancy by stopping you ovulating (releasing an egg each month), thinning the lining of the womb and thickening the mucus in the neck of the womb, making it harder for sperm to reach an egg.

Each combined pill pack contains 21 tablets which traditionally, you will take consistently before taking a break. During said break you might have a withdrawal bleed which can be caused by a drop in hormone levels. You might experience symptoms similar to your period, but it is usually a lot lighter and shorter.

You can also take the combined pill as a tailored regimen. This may include taking the pill for 21 days and stopping for 4, taking 2 or 3 packets back to back without a break, or taking the pill continuously without a break. For more information speak to your doctor or nurse.

Reviewed and edited on 04/03/21 in line with our content policy.

  1. NHS
  2. Family Planning Association
  3. Patient UK

Sophie is a Cardiff University- trained journalist who is passionate about sharing womens’ contraception stories in the hope that it will connect with others.

You can find her on Twitter.