--- title: "Thinking About The Contraceptive Implant? Here's What To Know" slug: contraceptive-implant-what-to-expect lifeStage: cycle category: Cycle medicalReviewer: 'Dr Shree Datta, Consultant Obstetrician and Gynaecologist ' reviewerId: 'https://blog.bloume.com/cycle/medical-board.md#dr-shree-datta' lastUpdated: '2026-07-24' primarySource: 'NHS - Contraceptive implant' --- # Thinking About The Contraceptive Implant? Here's What To Know The contraceptive implant is a small, flexible plastic rod that sits under the skin of your upper arm. It releases a progestogen hormone steadily, making it more than 99% effective at preventing pregnancy for up to three years. The most common thing you might notice is a change to your bleeding, which can range from no periods at all to irregular or longer bleeding. This article covers how the implant works, what to expect from your cycle, and what the evidence says about mood and energy. **Q: How quickly does the contraceptive implant start working?** A: If the implant goes in during the first five days of your cycle, it works straight away. If it is fitted at any other point, you will need to use extra protection, such as condoms, for the first seven days. Your clinician will talk you through the timing when you have it fitted. The tenderness in your arm after fitting, or the unpredictable spotting that follows, can leave you wondering what is normal. If you are considering the implant or have just had one fitted, this article covers what to expect. The implant, sold in the UK under the brand name Nexplanon, is a small, flexible plastic rod, about 4cm long, that sits under the skin of your upper arm. It contains a progestogen called etonogestrel, and it is one of the most effective forms of contraception available, more than 99% effective over its three-year licensed life. ## How the contraceptive implant works Once it is in place, the implant releases etonogestrel steadily into your bloodstream. It works in three ways. Mostly it stops your ovaries from releasing an egg. It also thickens the mucus at your cervix, so sperm struggle to pass through, and it thins the lining of your womb. Together these make pregnancy very unlikely. Because the hormone releases continuously, there is no daily pill to remember. That takes user error out of the picture, which is why the implant works just as well in everyday use as it does in perfect use. Methods that rely on daily action tend to show a gap between the two. The implant counts as a long-acting reversible contraceptive (LARC), a method that lasts for years and can be reversed. Once it is removed, your fertility returns to normal straight away. ## How the implant differs from the IUD and the pill The implant sits in your upper arm. An intrauterine device (IUD) or intrauterine system (IUS) goes inside your womb. Both the implant and the hormonal IUS release a progestogen, but they do it differently. The implant works through your whole system, with the hormone entering your bloodstream and acting throughout your body. The IUS works more locally, releasing the progestogen mainly inside your uterus. That difference in how the hormone reaches you is one reason the two methods can feel different, even though they use the same kind of hormone. The combined pill and the progestogen-only pill both need daily attention. Missing one, or taking it at the wrong time, can lower how well it works. The implant takes that out of your hands, which is why it sits in the LARC group alongside the IUS and IUD. None of this makes one method better than another. Each comes with its own benefits and trade-offs, and the right choice depends on your health, your preferences, and what suits you. ## What happens to your bleeding pattern Changes to your bleeding are the most common thing you might notice with the implant. Around one in five people stop having periods altogether, known as amenorrhoea. Nearly half have bleeding that turns infrequent, frequent, or longer than usual. A smaller number keep a regular pattern much as before. Irregular bleeding is most common in the first three to six months. For you it may settle after that, or the unpredictable bleeding may carry on the whole time the implant is in. This is a normal response to the steady hormone release, and it does not mean the implant has stopped working or that something is wrong. > **INFO**: If your bleeding pattern is worrying you, for example if it is very heavy or carries on for a long time, it is worth speaking to your GP or a sexual health clinician. They can talk you through options for managing the pattern if it is affecting your daily life. ## How the implant may affect mood and energy Some people notice low mood or emotional changes after having the implant fitted. Mood changes are a possible side effect, though they are not common, and the research picture here is mixed. Where they do happen, they often ease within the first few months as your body settles into the steady hormone level. If you notice mood changes that feel significant or stick around, it is worth raising with a GP or sexual health clinician rather than sitting with it alone. They can help you weigh up whether to stay with the implant or look at an alternative. ## Other side effects worth knowing about Headaches, acne, breast tenderness, and nausea are all possible side effects. They tend to ease after the first few months. On weight gain, there is no clear answer on this yet. How you respond to any hormonal method is personal, and if you are concerned about changes you are noticing, a clinician can help you look at the full picture. ## How long it lasts and what happens when it is removed Nexplanon is licensed for three years in the UK. At that point, a clinician takes out the existing rod and can fit a new one if you want to carry on with this method. Removal is a minor procedure, much like the insertion. Once the implant is out, the hormone clears quickly and your fertility returns to normal straight away, so there is no waiting period before you can conceive if that is your plan. > **WARNING**: This article is general health information and not a substitute for personalised clinical advice. If you have questions about whether the implant is right for you, or you are noticing side effects that concern you, speak to your GP or contact a sexual health service. **Q: How quickly does the contraceptive implant start working?** If the implant goes in during the first five days of your cycle, it works straight away. If it is fitted at any other point, you will need to use extra protection, such as condoms, for the first seven days. Your clinician will talk you through the timing when you have it fitted. **Q: Will my periods go back to normal after the implant is removed?** Your fertility returns to normal as soon as the implant comes out. Your cycle starts up again, though it may take a few weeks to settle into a regular pattern. If your periods have not returned within a few months of removal, it is worth speaking to your GP. **Q: Can the contraceptive implant affect my mood?** Mood changes are a possible side effect, though the research picture here is mixed. Some people notice low mood or emotional changes, particularly in the first few months. If yours feel persistent or are affecting your wellbeing, speak to a GP or sexual health clinician rather than stopping the implant yourself. Removal should always be done by a trained clinician. **Q: Does the contraceptive implant cause weight gain?** The current evidence does not show the implant causes weight gain. Experiences vary, and if you notice changes you are concerned about, a clinician can help work out what may be behind them. **Q: How is the implant different from the hormonal coil?** Both the implant and the hormonal coil (IUS) release a progestogen, but they work differently. The implant sits in your upper arm, and the hormone acts through your whole system, entering your bloodstream and circulating throughout your body. The IUS goes inside your womb and works more locally inside your uterus. Both are long-acting reversible methods, but the fitting, the placement, and the side effects can differ. Talking both options through with a clinician will help you decide which suits you. ### Clinical Sources - [NHS - Contraceptive implant](https://www.nhs.uk/contraception/methods-of-contraception/contraceptive-implant/what-is-it/) - [West Suffolk NHS Foundation Trust - Contraceptive Implant](https://www.wsh.nhs.uk/CMS-Documents/Patient-leaflets/Maternity/6653-1-Contraceptive-implant.pdf) - [NHS - Contraceptive implant](https://www.nhs.uk/contraception/methods-of-contraception/contraceptive-implant/what-is-it/) - [Methods of contraception](https://www.nhs.uk/contraception/methods-of-contraception/) - [NHS - How different methods of contraception are used](https://www.nhs.uk/contraception/choosing-contraception/how-it-is-used/) - [FSRH Guideline: Progestogen-only Implants](https://www.cosrh.org/Common/Uploaded%20files/documents/fsrh-guideline-progestogen-only-implants.pdf) - [Sexual Health Sheffield - The Contraceptive Implant](https://www.sexualhealthsheffield.nhs.uk/wp-content/uploads/2019/06/Contraceptive-Implant-August-2021.pdf) - [Contraception and mental health: keeping well NWL](https://www.keepingwellnwl.nhs.uk/self-help-resources/womens-health/contraception-and-mental-health) - [NHS - Contraceptive implant](https://www.nhs.uk/contraception/methods-of-contraception/contraceptive-implant/what-is-it/) - [NHS - Contraceptive implant](https://www.nhs.uk/contraception/methods-of-contraception/contraceptive-implant/what-is-it/) --- Reviewed by Dr Shree Datta, Consultant Obstetrician and Gynaecologist | [Medical Board](https://blog.bloume.com/cycle/medical-board.md) | July 2026