Reviewed by Dr Samantha Miller MB ChB
(2017, University of Glasgow)
GMC number: 7561464
Information last reviewed 23/02/2021
Loestrin is a type of combined contraceptive pill. More commonly referred to as ‘the pill’, it is an effective and popular method of preventing pregnancy containing oestrogen and progestogen hormones.
Loestrin contains ethinylestradiol and norethisterone which are synthetic versions of oestrogen and progestogen, similar to the hormones that the body naturally produces. These hormones work to prevent ovulation from happening so that an egg does not get released into the womb to be fertilised. They also create a thinner womb lining so that an egg would be unable to attach itself to the uterine wall. Furthermore, the mucus that lines the entrance of the womb from the vagina thickens, preventing sperm from being able to enter.
When taken correctly, Loestrin is over 99% effective. Forgetting to take it is one of the main reasons the pill becomes less effective. It can also be affected by vomiting and diarrhea or certain medications. Always familiarise yourself with the instructions provided with Loestrin before starting it so that you are aware of how it works. Typically, this pill is around 91% effective in practice.
Loestrin will start to work right away if you start taking it on the first day of your period. If you begin your first pack after this then you will need to use condoms for the first seven days until Loestrin takes effect.
While Loestrin is predominantly used to prevent pregnancy, it also provides some additional benefits. It can be used to delay your period, to ease painful periods, and to reduce the symptoms of PMS. The pill causes you to have an artificial menstrual cycle that is regular and easy to control.
Each Loestrin 20 pill contains 1mg norethindrone acetate and 20 mcg ethinylestradiol.
Each Loestrin 30 pill contains 1.5mg norethindrone acetate and 30 mcg ethinylestradiol.
The inactive ingredients in Loestrin are: acacia, lactose, magnesium stearate, starch, confectioner's sugar and talc.
The best time to start Loestrin is on the first day of your period as you will be protected against pregnancy right away. If you start at any other time during your cycle, you'll need to use additional methods of contraception, such as condoms, for the first seven days. If you are switching from a different brand of combined pill, you should finish your current pack and begin taking Loestrin the next day. In this way, you will be protected from pregnancy right away.
Loestrin should be taken once a day at the same time each day. Each pill pack contains a 21 day supply. You'll take the pill every day for 21 days and then have a seven-day break before starting the next pack.
If you have missed a pill (i.e. you are more than 12 hours late in taking it) then your contraceptive cover may be affected. Take the missed pill as soon as possible, even if this means you are taking two on the same day. Continue with the rest of the pack as normal and use extra precautions for seven days. If you have missed two or more pills then your contraception is more likely to be affected. Take the most recent missed pill as soon as you can and continue taking the rest of your pack on time. You'll need to use condoms for the next seven days to ensure you don't fall pregnant. If you have had unprotected sex since you missed a pill then you may need emergency contraception. Seek advice from your doctor, pharmacist or sexual health clinic as soon as possible.
If you take your pill within 12 hours of your scheduled time then your protection against pregnancy won't be affected. If you are more than 12 hours late, follow the instructions for a missed pill.
It's common to experience side effects when you first start taking Loestrin but these should subside after the first couple of months. Drink plenty of water and take painkillers if you experience headaches or cramps. It's normal to have breakthrough bleeding in the first month so be prepared with tampons and sanitary pads to ensure you are comfortable. Practice self-care if you experience mood changes and be mindful of how you are feeling. If you are struggling with side effects after the first few months of taking Loestrin, speak with your doctor as there may be a better type of contraceptive for you.
There are some serious side effects associated with the pill which you should be aware of before taking it. The combined pill increases the risk of high blood pressure, blood clots and some cancers. These side effects are rare, however, and your doctor will assess your medical history and any underlying conditions to determine if the pill is suitable for you or not.
Common side effects include:
Loestrin may cause worsening of the following conditions
The pill should not be taken if:
Certain medications interact with the way Loestrin works. These include:
Drinking alcohol does not have an effect on Loestrin.
Loestrin has been discontinued by the manufacturer, so it is no longer available through Dr Felix. There is no alternative pill that contains exactly the same hormones, however, there are various pills that contain the same dose (30mg) of oestrogen:
Alternatives to Loestrin 20 which also contain a lower 20 micrograms dose of oestrogen (20 micrograms ethinylestradiol) are:
Your doctor can help you identify which pill is best for you to take instead of Loestrin.
Loestrin 20 has a lower dose of oestrogen than other brands of the combined pill making it a milder option that may suit some women better. Similar combined pills with a low-dose of oestrogen are Gedarel, Mercilon, Femodette, Millinette and Sunya.
If oestrogen is not suitable for you, you might consider a progestogen-only pill e.g. Cerelle.
Longer term alternatives to the pill include the copper coil, the hormonal coil, the contraceptive implant, injection or patch. None of these options will protect against STIs; male and female condoms are the only method of contraception that prevents a sexually transmitted infection.
Loestrin is not suitable for everyone. For women who cannot take the combined pill, the mini-pill may be a viable alternative. Also known as the progestogen-only pill, in contrast to Loestrin, it only contains the progestogen hormone. This means it produces fewer side effects and won't cause high blood pressure. It cannot be used to control your period in the same way as Loestrin and is taken every day throughout the month, rather than for 21 days.
When switching contraceptive pills you can usually start your new pill right away without any issues. However, it may depend on which type of pill you are switching from so ensure you follow your doctor's advice about how to start Loestrin. In most cases, when switching between brands of combined pills, you should finish your current pack and then start Loestrin the next day. As a precaution, you may be advised to use condoms for the first seven days of swapping pills.
One of the advantages of Loestrin is that it can be used to delay your period. The pill is usually taken for 21 days before having a seven-day break. To delay your period with Loestrin, run two packs back-to-back instead of having your usual pill-free week. This will skip your period until the end of your next pill pack.
Vomiting or diarrhoea can cause Loestrin to become ineffective. In this case, try to continue your pills as normal, but use additional barrier contraception for the duration of your illness and for 7 days thereafter. If those seven days overrun the end of the pack, the next pack should be started without a break.
Some women may get pregnant as soon as they stop taking Loestrin but for others, it can take longer. When you come off the pill it can take a couple of months for your natural menstrual cycle to return as your body adjusts. Loestrin does not have a long-term effect on your fertility but there are many other factors to consider for a healthy conception such as a healthy diet and not smoking or drinking alcohol.
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