Let’s talk about contraception – Short Acting Contraceptives

Short Acting Contraception

Short Active Reversible Contraceptives

Consultant Obstetrician and Gynaecologist at the Rotunda Hospital, Dr. Vicky O’Dwyer sat with us to answer common questions related to Contraception. In particular, in this section, we will focus on questions about Short Acting Contraception.

Click on the highlighted text to watch Dr. O’Dwyer’s video response.

Short Acting Reversible Contraception is a category of contraceptive options that are user-dependent and need to be taken daily, weekly, or monthly. Their efficacy is very high when used perfectly (the so-called “perfect use”) – over 99% effective. Sometimes however, people do not use them correctly and consistently (for example, they don’t take the pill around the same time every day, they forget to insert the ring or to apply a new patch). This is called “typical use”, and in these cases the efficacy may be reduced. This category includes hormonal methods and barrier methods.

The use of contraceptives does not have a long-term negative impact on fertility. You can stop using them and get pregnant within your next cycle. What can happen is your period can be a bit delayed. Contraception may also be masking an underlying condition like PCOS, where you do not ovulate. However, most people come off contraception and get pregnant without any difficulties.


You can find all videos linked through this article in the video below:

Let’s see some contraceptive options in this category:

The Combined Oral Contraceptive Pill 

The combined pill contains artificial oestrogen and progesterone and has to be taken around the same time everyday. The hormones are absorbed into your body and result in:

  • The ovaries do not release eggs (no ovulation)
  • The cervical mucus thickens so it is harder for the sperm to swim through
  • The womb lining thins. This prevents a possible fertilised egg implanting

The pack comes with 21 contraceptive pills. Usually, you take one pill per day, for 21 days. Then you take a 7-day break, before starting another pack. Sometimes the pack may also contain 7 inactive pills (placebo) that you have to take during the 7-day break.  During the break, you may bleed. This is not a real period, it is a “withdrawal bleed” : it is your body’s response to the hormones’ level changing. However, it is not dangerous to take the pill back to back, without the 7-day break. This actually increases the contraceptive effect of the pill. Running pill packs back-to-back also reduces some of the side effects you may get during the 7-day break. Some people may get spotting when they run more than three packs together. For this reason,  they may want to take a break after three packs, but you don’t have to take a break at all. Talk to your doctor or nurse about the break.

Some medication may affect the efficacy of the pill. It is important to discuss any medication you may be taking with your doctor or nurse when deciding which contraceptive option is best for you. If you vomit within three hours of taking the combined pill, you may not have fully absorbed it and you may not be covered. Talk to your doctor if this is the case and remember to use another form of contraception like the condoms in this period.

The Vaginal Ring 

The vaginal ring is a small flexible ring that you insert in the vagina and works similarly to the combined pill, releasing artificial oestrogen and progesterone. This results in:

  • The ovaries do not release eggs (no ovulation)
  • The cervical mucus thickens so it is harder for the sperm to swim through
  • The womb lining thins. This prevents a possible fertilised egg implanting

You  leave the ring in the vagina for 3 weeks. Then you remove it, you may take a break (up to 7 days, or no break at all) before putting in a new ring. You can talk with your doctor or nurse about the break.

The Patch

The patch is similar to a plaster that you place on your butt, upper outer arm, lower abdomen or upper body. It needs to stay there for 1 week. You then put a new patch on every week for three weeks (21 days) in a row. When you remove the third patch, you may take a break (up to 7 days) before putting on a new one. You can talk with your doctor or nurse about the break.

It is similar to the combined pill (oestrogen and progesterone), but your body absorbs the hormones through the skin. This results in:

  • The ovaries do not release eggs (no ovulation)
  • The cervical mucus thickens so it is harder for the sperm to swim through
  • The womb lining thins. This prevents a possible fertilised egg implanting

Non-Hormonal Short Acting Reversible Contraception

Barrier Methods

Barrier methods work by physically prevent the sperm from reaching the egg. You either put them on the erect penis or inside the vagina. In this category, there are the male condoms, the female condoms, and the diaphragm. Both male and female condoms reduce the risk of transmitting STIs, especially the ones that are transmitted only by genital fluids (like gonorrhoea, chlamydia, trichomoniasis, and HIV infection). It is a good idea to combine two different birth control options, like the pill and the condom, so that you can protect yourself and your partner against STIs as well as unwanted pregnancies.





Male condoms are external and usually made of latex. You place it on the erect penis and it collects the sperm so it doesn’t enter the vagina, acting as a barrier. Since condoms cover the penis, they prevent transmission of STIs as well as preventing pregnancy. Be mindful though, that some STIs may still be transmitted (those that are transmitted through skin-to-skin contact, as some skin would still be exposed) such as genital herpes, human papillomavirus (HPV) infection, syphilis. Remember that condoms come in different sizes: an ill-fitting condom may slip if it is too big, may break if it is too small and overall, just makes things very uncomfortable! Each brand has its own size charts, where you can check out the right one to use.

Female condoms are similar to male condoms, but work the other way around. They are thin plastic pouches that you put into the vagina. This is also a barrier method of contraception and prevents transmission of STIs including HIV.

Diaphragms/ Caps

The diaphragm is a soft silicone device that you place into the vagina and covers the cervix. Since it just covers the cervix, this barrier method does not prevent the spread of STIs. This barrier prevents the sperm entering the uterus and reaching the egg.

A doctor needs to assess you to understand which size fits you best. Spermicide gel kills sperm so you can use it in conjunction to provide more protection against pregnancy.

For more information, visit the dedicated page on the HSE website.

Debunking the Myths – The Science behind Our Sexual Health is a series of expert-led workshops and interactive tools for teenagers focused on sexual health. It is developed by the RCSI (Royal College of Surgeons in Ireland) Department of Obstetrics and Gynaecology in collaboration with the Rotunda Hospital to supplement the Relationship Sexuality Education (RSE) curriculum.

The aim of the project is to provide clear and factual information in relation to sexual health and stimulate open discussion and curiosity around the topic. For more information visit Debunking the Myths on Instagram or TikTok.