What the implant is and how it prevents pregnancy
The contraceptive implant is a small, hormone-based device placed under the skin of your upper arm to prevent pregnancy. It is an implantable medical device used for birth control, and it is approved in more than 60 countries and used by millions of women worldwide (Wikipedia).
It works by releasing hormones in a timed way that interferes with ovulation or sperm development, which is how it stops a pregnancy from starting (Wikipedia). One thing it does not do is protect you from sexually transmitted infections — like other contraceptives, it is designed to prevent pregnancy only (Wikipedia). If you also need protection from STIs, that has to come from a separate method such as condoms.
How effective it is
The implant is described as highly effective, and that high effectiveness is the main reason people choose it over methods that depend on remembering something every day (Wikipedia). The NHS frames the same point in practical terms: its implant page is built around how effective the method is, alongside how it works and how to get and use it (NHS).
What changes the answer for you is consistency. The implant’s protection does not depend on a daily pill or a routine you have to keep up. Is the tradeoff that makes it attractive if you know your schedule is unpredictable. The effectiveness figures you should rely on are the ones on the NHS page for the method. Check the current number there rather than assuming a figure from memory (NHS).
How it is put in and what the routine looks like
The implant is most commonly inserted under the skin (subdermally) in the inner portion of the upper, non-dominant arm, and it is placed by a trained and certified health care provider (Wikipedia). That is the practical routine: a clinician places it, and once it is in, there is nothing daily for you to do.
The condition that changes this is who does the procedure. Because insertion is done by a trained and certified provider rather than by you at home, your first practical step is booking with a service that offers the implant. The NHS page covers how to get it (NHS). Ask at that appointment about the removal plan at the same time. You know from the start how the device comes out and who to contact when you want it gone.
Side effects and what to expect
Because the implant is hormone-based, the effects you may notice are hormonal ones, and the NHS page on the method is the place to read the specific side effects listed for it (NHS). Knowing what is listed there before insertion means you can tell the difference between an expected effect and something that needs a clinician’s attention.
The condition that changes how you should read that list is your own history. If you have had a strong reaction to hormonal contraception before, raise it at your appointment rather than after insertion, because that conversation is what shapes whether the implant is a sensible choice for you. The NHS page sets out the side effects alongside how the method works and how effective it is, so you can read them together (NHS).
Who it suits
The implant tends to suit people who want a method that does not depend on a daily routine and who are comfortable with a device placed under the skin of the arm by a clinician (Wikipedia). It is a hormone-based method. It also suits people who are happy to use hormonal contraception and who do not need STI protection from the same method (Wikipedia).
The condition that changes the answer is what you need the method to do. If you need protection from sexually transmitted infections as well as pregnancy, the implant alone will not cover that, and you will need a second method (Wikipedia). If your priority is a method you do not have to think about day to day, the implant fits that description, and the NHS page sets out how to get and use it so you can judge the fit against your own circumstances (NHS).
If something goes wrong or you want it removed
If something goes wrong, the fallback step is to go back to a trained health care provider. The same kind of certified clinician who inserted the implant. Rather than trying to manage it yourself (Wikipedia). Removal is a clinical step. The person to contact is the service that provides the implant, and the NHS page is the route to finding that service and understanding how the method is managed (NHS).
What changes this answer is timing. If you want the implant out, contact the providing service and ask about removal rather than waiting for a routine review, and if you have symptoms that worry you, treat that as a reason to seek clinical advice promptly. The practical boundary is simple: insertion and removal both belong with a trained provider. Your action is to contact that provider, not to attempt anything at home (Wikipedia).