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How effective is spermicide?

There are lots of different birth control methods out there. And some of them are more effective than others. So, what about spermicide? What are its pregnancy prevention powers like? Can it prevent sexually transmitted infections? And how does it work, exactly? Let’s answer all of these questions – and more – in our deep dive into spermicide.

What is spermicide?

Spermicide has a long history, with the first written record of its use dating back to Ancient Egyptian times, in 1850 B.C.E. But back then, the spermicide used was crocodile dung and fermented dough.

Another text mentions the use of seed wool, acacia, dates, and honey mixture as a spermicide a few hundred years on, in 1500 B.C.E.

These ancient birth control concoctions were used in the same way as modern spermicide. That is, they were inserted inside the vagina to prevent pregnancy. However, these days spermicide isn’t made using honey or dung (thankfully!). It uses chemicals that are toxic to sperm, usually nonoxynol-9 or octoxynol-9, that are inserted deep into your vagina before sex.

How does spermicide work?

Although the name ‘spermicide’ implies that it kills sperm, it actually doesn’t. Instead, it works to prevent pregnancy in two ways. The first is by blocking the entrance to your cervix, meaning that sperm can’t reach your eggs. Secondly, it slows the sperm down so they’re unable to swim to the eggs.

Spermicide comes in lots of different forms, including gels, creams, foams, films, and suppositories. Most types of spermicide are inserted by using an applicator, while films and suppositories are usually placed in the vagina by hand. 

Every spermicide product is different (make sure you read the instructions carefully), but most need to be inserted into the vagina ahead of sex, usually by at least 15-30 minutes – and they usually only work for an hour. 

How effective is spermicide at preventing pregnancy?

Spermicide isn’t as effective as some other methods of birth control. With perfect use, around 18 out of 100 people who use it will become pregnant each year, meaning that it’s around 82% effective.

However, it’s very hard to use spermicide correctly every single time. That means, that in reality, around 21 people out of every 100 who use it will become pregnant each year, meaning that it has a typical use effectiveness of 79%.

If preventing pregnancy is your aim, it’s best to use spermicide alongside another birth control method like condoms. Make sure you check the manufacturer’s instructions of each method before using multiple types of contraception.

You can also use spermicide with Natural Cycles hormone-free birth control, but we recommend using it alongside condoms on Red Days to get an increased level of protection.

Does spermicide protect against STIs?

In a word: no. Spermicides don’t prevent sexually transmitted infections, so it’s essential that you use them alongside barrier methods of birth control like condoms.

There’s even a small risk of spermicide may increase the risk of infections. That’s because the chemicals used in spermicides can irritate the vagina, causing tiny micro tears, this may make you more prone to urinary tract infections, but it can also make it easier for STIs to enter your body. That’s another great reason not to rely on spermicide alone, but to use it alongside condoms for extra protection. 

What are the benefits of spermicide?

It’s one of the easiest methods to get your hands on. An over-the-counter birth control method, you can usually find spermicide in the drugstore or supermarket (usually near the condoms). Alternatively, you can order it online for home delivery. You may also be able to get spermicide at a reduced cost or for free from Planned Parenthood.

It’s also a hormone-free method of birth control, meaning it doesn’t use synthetic estrogen or progesterone to prevent pregnancy. Hormonal methods, such as the birth control pill, have been linked to some unpleasant side effects, such as low sex drive, mood changes, and headaches.

What are the disadvantages of spermicides?

As far as birth control methods go, spermicide on its own isn’t very effective. You need to use it perfectly every time to get the most out of the method – and even then, it’s still not particularly effective compared to some other methods. To get the most protection, it’s a good idea to use spermicide as another level of protection with another method, such as condoms.

While spermicide is hormone-free, it’s not a natural birth control method. The chemicals used in spermicides can be irritating, especially if you use them more than once a day. That can make sex uncomfortable and may cause small tears inside your vagina, leading to an increased risk of contracting STIs and UTIs.

Since you need to insert spermicide in advance of sex, it does require a certain amount of planning. Remember that you’ll need to wait a little while after inserting the spermicide to let it work before you can have sex. 

Discover more hormone-free options

When it comes down to what type of birth control you decide to use, it’s your choice. But it’s always important to know the advantages, disadvantages, risks, and benefits of any type of contraception.

If you’re keen to try a non-hormonal method of birth control, Natural Cycles could be a good option for you. It works by using the basal body temperature method, along with a smart algorithm that learns the patterns of your menstrual cycle. With typical use, it’s 93% effective, and with perfect use, it’s 98% effective. Sign up and find out how it could work for you today.

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Written By

Lauren McKay

Lauren McKay is a writer and journalist with more than ten years of experience writing across a variety of topics. She is a passionate advocate for driving women’s health knowledge and is a trained yoga teacher. She earned a Masters in Creative Writing from the University of Glasgow and currently lives in Scotland.

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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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