Birth Control Effectiveness: Switching Brands and Emergency Contraception

Inquire about contraceptive effectiveness?

Hello Doctor: (1) My girlfriend started taking her first pack of birth control pills (21 tablets) on the fifth day of her menstrual cycle last month.
After finishing the first pack, she began the second pack (also 21 tablets) seven days later, but switched to a different brand.
I would like to know if changing to a different brand affects the contraceptive effectiveness? (2) During the second pack, we had intercourse on the day she was supposed to take the fifth pill, and afterwards we discovered that the condom had broken (which means there was ejaculation inside).
We quickly went to see a gynecologist and informed the doctor that she was already taking the 21-day contraceptive pills.
The doctor prescribed emergency contraception and stated that she could continue taking the regular birth control pills.
However, I did not clarify whether we needed to use additional contraceptive methods afterward, so I would like to ask you if taking the emergency contraception would affect the effectiveness of the regular birth control pills she was already taking.
My girlfriend has been taking her birth control pills consistently every day, but we have not used any other contraceptive methods since taking the eighth pill.
Therefore, I would like to know if taking the emergency contraception on the fifth day of her regular birth control pill cycle would impact the effectiveness of the ongoing use of the regular birth control pills.

Ding Ding, 20~29 year old female. Ask Date: 2018/07/24

Dr. Huang Jianzhong reply Obstetrics and Gynecology

(1) My girlfriend started taking her first pack of birth control pills (21 pills) on the fifth day of her menstrual cycle last month.
After finishing the first pack, she began the second pack (also 21 pills) seven days later, but switched to a different brand.
I want to know if switching to a different brand affects the contraceptive effectiveness.
Answer: No, switching to a different brand will not affect the contraceptive effectiveness.
(2) During the second pack, we had intercourse on the day she was supposed to take the fifth pill and later discovered that the condom broke (which is equivalent to ejaculation inside).
We quickly went to see a gynecologist and informed the doctor that she was already taking the 21-pill contraceptive.
The doctor prescribed emergency contraception and advised that she could continue taking the birth control pills.
However, I did not clarify whether we needed to use additional contraceptive methods afterward, so I would like to ask you if taking the emergency contraception would cause the birth control pills she was already taking to become ineffective.
My girlfriend has been taking her birth control pills consistently every day, but we have not used any other contraceptive methods since taking the eighth pill.
Therefore, I would like to know if taking the emergency contraception on the fifth day of her birth control pill regimen affects the effectiveness of the ongoing birth control pills.
Answer: Taking emergency contraception while already on the 21-pill birth control is unnecessary but does not affect the effectiveness of the ongoing birth control pills.

Reply Date: 2018/07/24

More Info

When it comes to understanding the effectiveness of birth control methods, particularly in the context of switching brands and the use of emergency contraception, there are several important factors to consider.

1. Switching Brands of Birth Control Pills: In general, switching from one brand of oral contraceptive to another does not inherently affect the effectiveness of birth control, provided that the new brand contains the same active ingredients and is taken correctly. Most birth control pills contain either a combination of estrogen and progestin or progestin alone. If your girlfriend switched to a different brand that also contains the same hormones in similar dosages, she should remain protected against pregnancy. However, it is crucial to start the new pack immediately after finishing the previous one without any gaps. If there is a gap of more than seven days between packs, additional contraceptive measures should be taken during that time.

2. Emergency Contraception: In the scenario where a condom broke and your girlfriend took emergency contraception (EC), it is important to understand how this interacts with her ongoing use of birth control pills. Emergency contraception is designed to prevent pregnancy after unprotected intercourse and works primarily by delaying ovulation. If she continues to take her regular birth control pills as directed after taking the emergency contraceptive, her birth control should remain effective. The emergency contraceptive does not negate the effectiveness of the birth control pills; however, it may cause some temporary hormonal fluctuations that could lead to irregular bleeding or changes in her menstrual cycle.

3. Continued Use of Birth Control Pills: Since your girlfriend has been consistently taking her birth control pills daily, she should still be protected against pregnancy. It is essential to maintain this routine, as missing doses can lead to decreased effectiveness. The key is to ensure that she takes her pills at the same time every day and does not miss any doses.

4. Additional Contraceptive Measures: After taking emergency contraception, it is generally recommended to continue using her regular birth control method without needing additional contraception, as long as she resumes her pills as scheduled. However, if she experiences any side effects or irregularities in her cycle after taking the emergency contraceptive, it may be wise to consult with a healthcare provider for personalized advice.

5. Consulting a Healthcare Provider: If there are any concerns about the effectiveness of the birth control method being used, or if there are any side effects or unusual symptoms, it is always best to consult with a healthcare provider. They can provide tailored advice based on her specific situation and health history.

In summary, switching brands of birth control pills should not affect their effectiveness as long as the transition is made correctly. The use of emergency contraception does not render ongoing birth control ineffective, and as long as your girlfriend continues to take her pills consistently, she should remain protected against pregnancy. If there are any uncertainties or concerns, seeking guidance from a healthcare professional is always a prudent step.

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