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    How does the birth control patch work?

    Updated 04 April 2024 |
    Published 01 October 2018
    Fact Checked
    Medically reviewed by Dr. Jenna Beckham, Obstetrician and gynecologist, WakeMed, North Carolina, US
    Written by Kate Hollowood
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    Here’s everything you need to know about the birth control patch before giving it a try, with advice from a Flo expert.

    With many types of contraception to choose from, it can take some research and maybe even a little trial and error to figure out which is the right one for you. The birth control patch is a type of hormonal birth control, which means that it works by releasing hormones through your skin to prevent pregnancy.

    The patch is around 99.7% effective when used perfectly. This means using the patch exactly as it’s recommended. So, there’s a strong argument for adding it to your consideration list. But first, let’s find out what using the birth control patch involves, the possible side effects, and what other people using Flo have to say about it.

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    Key takeaways

    • The birth control patch is a small, sticky patch that releases the hormones estrogen and progestin into the bloodstream via your skin. 
    • The patch works on a four-week cycle. Every week for three weeks, you can wear a patch (even in the bath or shower) and change it weekly. During week four, you have a break and don’t wear one for seven days. Alternatively, you can wear the patch continuously
    • With perfect use, the patch is over 99% effective at preventing pregnancy, and with typical use, 93%. However, it doesn’t protect you from contracting a sexually transmitted infection (STI)

    What is the birth control patch?

    The birth control patch is small, square, and sticky, like a bandage, that you wear on your skin to prevent pregnancy. You can wear it on your shoulder or upper arm, just above your bottom, below your belly button, or near your shoulder blade on your upper back. It’s totally up to you where you choose to wear your patch, but you shouldn’t apply it to your chest area where it could get rubbed against by a bra or bra strap. You also should not put the patch on any areas that are red, irritated, or cut. Placing it on a new area of skin each time can be a good way of avoiding any irritation. You put a new patch on the same day each week for three weeks and then have a one-week break (unless you’re using the patch continuously). 

    How does the birth control patch work?

    The birth control patch works by releasing the hormones estrogen and progestin (a synthetic form of progesterone) into your bloodstream through the skin. These hormones work together to prevent pregnancy in three key ways:

    Preventing ovulation 

    Ovulation describes the process when one of your ovaries releases an egg to be potentially fertilized by a sperm. If you have a 28-day cycle, which is considered to be typical, then this usually happens around the midpoint of your cycle.

    “The birth control patch prevents you from ovulating (releasing an egg),” says Flo expert Dr. Ruth Olumba, obstetrician, gynecologist, and gynecologic and cosmetic surgeon, Texas, US. If there’s no egg to fertilize, then you can’t get pregnant.  

    Thickening cervical mucus 

    The patch also works by helping to stop sperm. “The patch thickens your cervical mucus to prevent sperm from reaching and thus fertilizing an egg,” says Dr. Olumba. The logic goes that if your cervical mucus (the slippery fluid produced by your cervix) is thicker, then it’ll be harder for sperm to swim through your cervix to reach your uterus. 

    Thinning uterus lining 

    The patch also thins the lining of your uterus. This means that even if a sperm did manage to swim through your cervix and fertilize an egg, it would be less likely to implant in the lining of your uterus (an essential step for a fertilized egg to develop into a pregnancy). 

    How effective is the patch?

    By preventing pregnancy in three different ways, the patch is a highly effective method of contraception. With perfect use, it’s over 99% effective. Perfect use means you apply your patch at the same time every week and promptly reapply your patch after your week break.

    Life can get busy, so if this isn’t the case for you all of the time, then you’re not alone. The patch is considered to be 93% effective with typical use. This considers any times you forget to apply your patch on time or leave it on for too long. This means that just 7 in 100 women using it a year will get pregnant. 

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    How to use the birth control patch

    So, if the contraceptive patch sounds like it might work for you and your lifestyle, here are some handy tips to help you use it effectively and build your confidence. 

    Remember to change your patch weekly 

    The birth control patch usually works in a four-week cycle. You need to change your patch weekly on the same day you started it — so every Sunday, for example — for the first three weeks. “Make sure you change the patch every week except for your patch-free week,” says Dr. Olumba. At the end of your patch-free week, or week four, the cycle repeats. Once you’ve used a patch for a week, you can throw it away and open a new one. If you’d prefer to have fewer break weeks, you can also wear the patch continuously

    If you’re ever more than 48 hours late to change your patch, you’ll need to use backup protection (like a condom) for at least a week afterward to protect yourself from pregnancy. It can be tough to remember exactly when to change your patch, so you can set the Flo app to send you a reminder to help you.

    Make sure the patch is stuck firmly to your skin

    Where you choose to wear your patch is entirely up to you. However, for it to work properly, the birth control patch needs to be stuck firmly onto your skin. “Apply the patch to skin that is clean, so free of makeup, oils, cream, fragrance, and moisture,” says Dr. Olumba. “And if the patch is falling off, make sure you discuss this with your doctor.” 

    Use backup protection for the first week to prevent pregnancy 

    If you start using the patch more than five days after the first day of your last period, you’ll need to use backup barrier protection like a condom for the first seven days. Dr. Olumba recommends always using condoms alongside the patch to protect you from STIs, as they’re the only form of contraception that has this benefit. 

    Potential side effects of using the patch 

    Knowing all of the benefits and potential side effects of different types of contraception can help you make a more informed decision when you’re exploring your options. The birth control patch can cause some unwanted side effects, including:  

    • Breakthrough bleeding or spotting (bleeding outside of your regular period) 
    • Skin irritation
    • Breast tenderness or pain
    • Headaches
    • Mood swings
    • Acne
    • Nausea or vomiting
    • Fatigue
    • An increased risk of blood clots, heart attack, and high blood pressure

    For most of these side effects, people find they are often minor and go away after they’ve been using the contraception for a couple of months. But if you start using the patch and find that you’re getting side effects that are really bothering you, Dr. Olumba says you should discuss it with your health care provider, who may recommend switching to an alternative method of contraception. 

    She adds, “Irregular vaginal bleeding with the patch in the beginning may last several months, but if the bleeding gets extremely heavy, contact your physician. And if you smoke, let your physician know, as smoking increases your risk of blood clots on this form of birth control.” Before starting a new form of birth control, your doctor should walk you through your health and lifestyle history to make sure the type you’re looking into suits you.

    It’s important to remember that when it comes to birth control, it isn’t one size fits all. Everyone is different. And for some people, the side effects of the patch aren’t all bad news. For example, some people find that it actually improves their acne. This is because the estrogen released by the patch can help to reduce the body’s levels of testosterone (a hormone that causes excess oil production in some people). When talking about their birth control and acne experience with the patch, one person using Flo said on Secret Chats, “My skin cleared, my hair was growing, my mood improved. I would recommend the patch 10/10!”

    Meanwhile, another wrote, “I stopped using the patch because I definitely noticed that it made me depressed. I experienced so many emotions I don’t normally get.” 

    Ultimately, the only way to know how you’ll react to the patch is to try it. So talk to your doctor, and if they give you the OK, give it a try and see what you think. 

    Does the patch stop your period?

    This is a good question and takes a little explaining. When you have your break week on the patch, you will have what’s called a withdrawal bleed. This can resemble a period, but it’s actually not the same thing. 

    “Although both might seem the same, periods are regulated by an ovulated egg not being fertilized that cycle, causing you to shed the lining of the uterus,” says Dr. Olumba. “Withdrawal bleeds on the other hand are not due to ovulation.” 

    In fact, withdrawal bleeding is simply your body’s response to stopping the hormones you’ve been getting on birth control. “Withdrawal bleeds tend to be less heavy, shorter, and less painful,” adds Dr. Olumba. 

    It’s important to know that not everyone will have a withdrawal bleed during their break week on the patch, and that this doesn’t necessarily mean it’s not working properly. If you’ve been using the patch correctly, it may be nothing to worry about, but you should contact your health care provider if you consistently don’t have a bleed during your break weeks. If you want to delay or avoid having a withdrawal bleed on the patch, you can skip your break and use the patch continuously

    If you’ve been using the patch for a little while, you might be curious when your period will return if you were to stop using it. It’s hard to say for sure, as everyone is different, but most people will find their periods return to normal a cycle or two after stopping hormonal birth control. You can track your cycle using an app like Flo to better understand what’s normal for you.

    So, is the patch right for you?

    Now that you have all the information you might need, you might have a better idea if the patch fits you and your lifestyle. “The patch is best for someone who wants reversible birth control but does not want to take a pill every day,” says Dr. Olumba. If you’re looking for contraception for first-time sex or are about to start birth control again after having a break, here are Dr. Olumba’s pros and cons of the patch: 

    The pros

    The cons

    • There can be some side effects, like breakthrough bleeding (this is especially common when initially starting the patch, says Dr. Olumba).
    • Forgetting to change the patch makes it less effective. 
    • You have to change it every week and remember your patch-free week. 
    • You can only get the patch with a prescription and after visiting your health care provider.
    • People with a body mass index of 30 kg/m2 or higher can’t use the patch, as it could potentially increase their risk of venous thromboembolism (blood clots). 
    • It doesn’t protect you against STIs.
    • Some drugs can affect the effectiveness of the patch, including antiviral drugs. Make sure you speak to your doctor about any other medications you’re taking before starting the patch. 

    More FAQs

    Is the patch good birth control?

    Yes, the patch is a highly effective form of contraception when you use it correctly. However, it’s worth repeating that it won’t protect you against STIs. For protection against pregnancy and STIs, you should use condoms as well as the patch. 

    Are you protected on your patch-free week?

    Yes. If you start using the patch within the first five days of your menstrual cycle, you’ll be protected from pregnancy immediately. If you start it on any other day of your cycle, you’d need to use backup protection for seven days. This means that you would be protected by the time you reach the patch-free week.

    Can you shower with the birth control patch?

    Yes, you can. You should keep the patch on when you take a bath, shower, or exercise. It should also be sticky enough to stay in place if you swim or use a hot tub or sauna.


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