Frequently Asked Questions: Birth Control Drugs
Questions & Answers
Many popular methods of birth control contain synthetic female hormones to prevent pregnancy. This page answers your questions about the most common hormonal contraceptives.
Frequently Asked Questions:
- Which methods contain hormones?
- What's the difference between the types of hormones?
- How do birth control chemicals work?
- Do I need to use a backup method in addition to my hormonal contraceptive?
- How long should I wait before trying to get pregnant?
- I have stopped using birth control. Why am I unable to conceive?
- Why have my periods stopped?
- I'm on combined OCs and didn't get my period. How can I tell if I'm pregnant?
- What if I forget to take a pill?
- What if I forget to take two or more pills?
- What if I vomit after taking the pill?
- Can I use oral contraceptives to change the date my period comes?
- Why am I having irregular bleeding?
- If I take my pill every day can I still get pregnant?
- I took the pill while pregnant. Can the hormones hurt my baby?
- Who should not use hormonal methods of birth control?
- Do birth control chemicals have unpleasant side-effects or health hazards?
- What happened to my sex drive?
- How much weight will I gain on a hormonal method of birth control?
- Will hormonal methods protect me from STDs?
- Are hormonal methods good for nursing women?
Which methods of birth control contain hormones?
What's the difference between the types of hormones?
Methods containing higher levels of hormones are more effective but have more side-effects.
Methods that contain estrogen have more serious side-effects and health hazards (such as heart attacks and strokes) than methods with only progestin. Estrogen-free contraceptives are less effective than combined hormonal contraceptives. Visit our hormonal contraceptive page for the chemical names of the different types of artificial hormones.
How do birth control chemicals work to prevent pregnancy?
Birth control chemicals containing estrogen and/or progestin have several major mechanisms of action.
Contraceptive mechanisms prevent fertilization; when these fail, additional mechanisms prevent implantation.
- Major Pre-Fertilization Mechanisms
- Prevention of ovulation.
- Changes cervical mucus to provide a barrier to sperm.
- Major Post-Fertilization Mechanisms
- Changes to the speed at which the fertilized egg moves down the fallopian tube prevent implantation.
- Changes to the (endometrium) lining of the uterus make it harder for the embryo to implant in uterus when it arrives.
More about post-conception mechanisms...
Do I need to use a backup birth control method in addition to my hormonal contraceptive?
If you start the Pill, Implanon, or Depo-Provera on the first day of your period, it is considered effective right away. It takes up to seven days for the hormones to become fully effective. However, the first seven days of a woman's cycle are already infertile, so no additional protection is required. If you start the method on any other day than the first day of your period, you need to use a backup plan for up to seven days. For the minipill, you may need a backup method for 28 days. Ask your doctor to be sure. For the Pill, some doctors recommend using a backup method for the first 30 days. This is mainly to be sure that a pregnancy does not occur while you are still getting in the habit of taking a pill every day.
I have just stopped my method because I want to have children. How long should I wait before trying to get pregnant?
It is recommended that you wait until you have had 2-3 normal menstrual cycles before trying to get pregnant. This is because it may take several months before your cycles return to normal after discontinuing a hormonal method. Doctors use the first day of your last menstrual period to determine your due date; if your periods are irregular this may result in an inaccurate date. Also, there is some evidence that birth control drugs may exert a prolonged effect on the endometrium, making it more difficult to become pregnant.
I have stopped using birth control. Why am I unable to conceive?
Because of the prolonged effect of the birth control drugs on your body, you may be infertile for some time. For combined oral contraceptives, the average length of infertility is 2-3 months, but some women will remain infertile for 6 months or more. For Depo-Provera users, infertility typically lasts from 6 to 12 months. You may not have any periods during this time.
Why have my periods stopped? Should I take a pregnancy test?
For users of combined oral-contraceptives, missing a period is not uncommon. If you have not missed a pill you are probably not pregnant, but a pregnancy test may not be a bad idea. If you miss two periods in a row OR if you miss your period and you did miss one of your pills, you could be pregnant. Contact your local pregnancy center immediately for a pregnancy test.
For users of progestin-only methods, like the min-pill, lack of periods is common. It probably means that you are not ovulating. However, if you are experiencing pregnancy symptoms (nausea, fatigue, sore breasts, frequent urination, etc.) contact your local pregnancy center for a pregnancy test right away.
Half of all Depo-Provera users have no periods at all during the first year of use. And pregnancy symptoms such as weight gain, mild headaches, and breast tenderness are also common side effects of the drug. This can be alarming for Depo-Provera users, but usually the pregnancy-like symptoms disappear. Even after using Depo-Provera, it takes on average 10 months from the time of the last injection for normal periods and fertility to return.
Other reasons why your period may be late.
If you have stopped using your method, it may take time for your periods to return to normal. See above.
I'm on combined OCs and didn't get my period. How can I tell if I'm pregnant?
If your period does not start during the last few days on the "reminder" pills or during the first 3 days of the pill-free interval, take your temperature with a Basal Body Temperature (BBT) thermometer in the morning before you get out of bed. (You can get a BBT thermometer from most drug stores.) If your temperature is 98 degrees F for 3 days in a row during the pill-free week, you are probably not pregnant. You can also take a home pregnancy test, which are usually accurate by the time you miss your period, or visit a local pregnancy resource center for a free, accurate test.
What if I forget to take a pill?
Combined OCs It is recommended that you take that pill as soon as you remember, and take your next pill at the regular time, even if it means you take two pills in one day. You will probably not get pregnant, but just to be sure, you might use a back-up method for 7 days. If you have missed any of pills 15-21, ask your doctor or pharmacist for special instructions. S/he may ask you to continue taking your pills, but to start a new pack instead of taking the reminder pills.
Progestin-Only OCs It is recommended that you take that pill as soon as you remember, and take your next pill at the regular time, even if it means you take two pills in one day. You will need to use a back-up method for the next 2 days.
What if I forget to take two or more pills?
Contact your doctor or pharmacist for instructions. You may need to start a new pack or double up on pills for a while depending on what type of pill you were taking.
What if I get sick and vomit after taking the pill?
If you took a combined oral contraceptive pill two hours or more before you vomited, then you do not need to take it again. If the vomiting ocurred within two hours, you will need a replacement pill.
Can I use oral contraceptives to change the date my period comes?
Yes, but you will need to talk to your doctor or pharmacist for details. This practice can compromise the effectiveness of the pill. You might also ask your doctor about a type of combined OC pill, extended cycle pills, where women get their periods only four times a year. It works by reducing the number of pill-free intervals which trigger menstruation.
Why am I having irregular bleeding?
Mid-cycle spotting is not uncommon for users of the pill, especially during the first few months of use. When this happens, typically doctors prescribe a stronger formulation of the pill. Spotting is an indication of decreased pill effectiveness, so some doctors recommend using a back-up method should spotting occur. However, spotting could also be a symptom of the STD chlamydia, so you should be tested if you are at risk.
Users of Implanon and Depo-Provera can expect irregular menstrual patterns. No periods, light periods, and even prolonged or heavy bleeding are all potential side-effects. If you have prolonged or heavy bleeding, you should contact your doctor.
If I take my pill every day can I still get pregnant?
Yes. All methods of birth control can fail, even if you use them perfectly. If you miss a pill, take a mini-pill only a few hours late, or take antibiotics that will increase the likelihood of contraceptive failure. One in ten pill users get pregnant every year.
I took the pill before I knew I was pregnant. Can the hormones hurt my baby?
There is no conclusive evidence that a brief exposure to birth control chemicals will cause any sort of birth defect in the unborn child. However, you should avoid taking if these drugs if you think you might be pregnant.
Who should not use hormonal methods of birth control?
- Women who are pregnant (known or suspected)
- Women who are breastfeeding and fewer than 6-8 weeks postpartum
- Women with unexplained vaginal bleeding
- Women with active liver disease (viral hepatitis) or a history of liver tumors
- Women over age 35 who smoke
- Women with a history of heart disease, stroke or high blood pressure
- Women with a history of blood clotting problems or diabetes
- Women with breast cancer or a history of breast cancer
- Women with cancer or a history of cancer in any reproductive organs
- Women with migraines and focal neurologic symptoms
- Women with moral objections to this type of birth control
Do birth control chemicals have unpleasant side-effects or health hazards?
- Common Side-Effects (not comprehensive)
- Weight gain
- Acne or dark-colored areas on face
- Nausea/Vomiting (especially at the beginning)
- Acne and/or oily skin
- Weight gain
- Vaginal infections
- High blood pressure
- Less Common Serious Health Hazards
- Blood clots in lung or brain
- Liver tumors
- Heart attacks
- Gallbladder disease
- Common Side-Effects (not comprehensive)
- Untimely bleeding or spotting between periods
- Prolonged menstrual bleeding (8 days or more)
- No bleeding at all (amenorrhea) for several months or over a year
- Headache (very common)
- Lower abdominal pain
- Loss of sex drive (libido)
- Acne and/or oily skin
- Change of appetite
- Weight gain
- Breast tenderness (mastalgia)
- Increased facial or body hair growth (hirsutism) or hair loss
- Whitish vaginal discharge (leukorrhea)
- Excessive growth of body/facial hair or hair loss
- Infection the implants site for Implanon
- A brief period of pain or itching
- Enlarged ovarian follicles
- Bone density loss
- Less Common Serious Health Hazards
What happened to my sex drive (libido)?
One of the most common complains we hear from women is that after starting hormonal contraceptives they just don't feel like having sex any more. Doctors frequently dismiss women's concerns about sex drive while partners are left sulking. Until recently, few studies have examined this issue, other than those conducted by pharmaceutical companies (which tend to be invested in not finding problems). Earlier studies found conflicting results. The most recent research has found that loss of libido is a common problem and may not be reversible.
Will I gain weight if I start the Pill or other hormonal method, and if so how much?
There is no one answer to this question. Weight gain is a very common side effect in response to hormonal birth control and varies on an individual basis. For most women, extra female hormones make fat deposition easier and increase the appetite. Conversely, weight loss usually becomes easier when hormonal birth control is discontinued.
For Depo-Provera the average weight gain is 5.4 lbs the first year, 8.1 lbs after two years, and 13.8 lbs after four years. But this is an average, and for many women weight gain can be extreme as this drug can increase the appetite. The average weight gain while on Implanon is 2.8 lbs after the first year.
Will hormonal methods protect me from sexually transmitted disease?
No. In fact, women who use Depo-Provera may double their risk of acquiring STDs, such as chlamydia, gonorrhea, and HIV.
Other hormonal contraceptives seem to also increase the risk of getting an STD.
This is because these drugs cause dryness in the genital tract, which facilitates small tears and abrasions, making it easier for infections to enter the body.
Also hormonal contraceptives may supresses the immune system, which makes it easier for infections to proliferate.
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