Birth Control Shots: Side Effects and Age Guidelines

Medication consultation

Can you tell me what side effects may occur after receiving a contraceptive injection? Is it true that it can cause amenorrhea for five months, as the school nurse mentioned? Also, can females under 20 years old receive the contraceptive injection?

Xiao Mi, 10~19 year old female. Ask Date: 2005/02/25

Dr. Wu Huiling reply Pharmacology

Hello! The principle of contraceptive injections is to administer hormones into a woman's body to suppress ovulation, alter the uterine lining to make it difficult for a fertilized egg to implant, and increase the viscosity of cervical mucus, making it harder for sperm to penetrate and enter the uterine cavity and fallopian tubes, thereby achieving contraceptive effects.
Contraceptive injections can be categorized into two types: single hormone and combined hormone injections.
Generally, women tend to use single hormone contraceptive injections (which contain only progesterone), effective for up to three months.
Combined hormone contraceptive injections (which contain estrogen and progesterone) have similar contraceptive efficacy to single hormone injections but require monthly administration.
The injection can be given within the fifth day of the menstrual cycle, but contraceptive effects only begin fourteen days after the injection; during this time, additional contraceptive methods, such as condoms, should be used.
Long-term use of contraceptive injections may lead to reduced menstrual flow and irregular light bleeding between periods, or even amenorrhea.
Women with a history of heart or vascular diseases, a family history of cardiovascular disease, diabetes, liver disease, abnormal uterine bleeding, breast cancer, reproductive organ cancers, or those who are already pregnant should not receive contraceptive injections.
Therefore, an assessment by healthcare professionals is necessary before administration to confirm suitability.
Initial injections may cause weight gain, dizziness, headaches, and breast tenderness, but these symptoms generally resolve quickly.
There may also be menstrual irregularities or reduced menstrual flow, and even amenorrhea.
These phenomena are typically reactions caused by progesterone and are not indicative of health issues.
If there is an increase in menstrual flow or prolonged periods, medical advice should be sought.
Another side effect of contraceptive injections is that women may take a longer time to regain fertility, generally within six to twelve months after the last injection.
While it does not lead to infertility, women planning to conceive in the short term should avoid this method of contraception.
A study published in Circulation: Journal of the American Heart Association warned that among volunteers aged 25 to 33 who received Depo-Provera injections, none had heart disease, but over a year later, their arterial function measurements were significantly lower than those who had never received this contraceptive injection.
Therefore, it is recommended that women who use this method long-term (for several years), especially those with certain high-risk factors for heart disease, including hypertension, smoking, a family history of coronary artery disease, or high cholesterol, should consider consulting with a doctor to determine if alternative contraceptive methods are necessary.

Reply Date: 2005/02/25

More Info

Birth control shots, commonly known as Depo-Provera, are a form of hormonal contraception that provides effective pregnancy prevention for up to three months with each injection. Understanding the side effects and age guidelines for using this method is crucial for informed decision-making.

Side Effects of Birth Control Shots
1. Menstrual Changes: One of the most common side effects of Depo-Provera is changes in menstrual bleeding patterns. Many women experience irregular periods, and some may stop having periods altogether after several injections. While some individuals may indeed experience amenorrhea (the absence of menstruation) for several months, this is not universally experienced and can vary significantly from person to person. It is important to note that while some women may not have a period for five months or longer, this is not a guaranteed outcome for everyone.

2. Weight Gain: Another frequently reported side effect is weight gain. Studies suggest that some women may gain weight while using Depo-Provera, although the amount can vary widely. Maintaining a balanced diet and regular exercise can help mitigate this risk.

3. Bone Density Loss: Long-term use of Depo-Provera has been associated with a decrease in bone mineral density. This is particularly concerning for young women, as peak bone mass is typically reached in the late teens to early twenties. Women who use this method for extended periods should discuss bone health with their healthcare provider and consider calcium and vitamin D supplementation.

4. Mood Changes: Some users report mood swings or changes in mental health, including depression. If a woman has a history of mood disorders, it is essential to discuss this with a healthcare provider before starting the shot.

5. Other Side Effects: Other potential side effects can include headaches, breast tenderness, and changes in libido.

Age Guidelines for Birth Control Shots
Regarding age guidelines, the Centers for Disease Control and Prevention (CDC) states that there is no minimum age requirement for receiving the Depo-Provera shot. However, it is generally recommended that individuals under 20 years old consult with a healthcare provider to ensure that this method is appropriate for their specific health needs and lifestyle.

Considerations for Young Women
For young women considering the birth control shot, it is crucial to have a thorough discussion with a healthcare provider. This discussion should include:
- Medical History: Understanding any pre-existing conditions or family history that may affect the choice of contraception.

- Lifestyle Factors: Considering how the shot fits into their lifestyle, including the potential for side effects and how they may impact daily life.

- Alternative Options: Exploring other contraceptive methods that may be more suitable, such as oral contraceptives, intrauterine devices (IUDs), or barrier methods.

Conclusion
In summary, while birth control shots can be an effective contraceptive method, they come with potential side effects that should be carefully considered, especially for younger women. It is essential to have open and honest discussions with healthcare providers to make informed choices about reproductive health. If you have further questions or concerns about the birth control shot or other contraceptive methods, do not hesitate to reach out to a healthcare professional for personalized advice.

Similar Q&A

HPV Vaccine Side Effects: Can It Affect Your Menstrual Cycle?

Hello, I usually have a regular menstrual cycle, but it tends to be delayed by about 10 days when I'm under stress. I received the first dose of the HPV vaccine on January 7, had my period on January 12, and then had another period on January 26. I would like to know if this...

Dr. Zhang Kunmin reply Obstetrics and Gynecology
Hello, the side effects of the HPV vaccine include: (1) Common side effects: pain, swelling, redness, itching at the injection site, fever, headache, nausea, and dizziness. (2) Rare side effects: diarrhea, rash, hives, joint pain, and fainting. There are many factors that can cau...

Understanding Birth Control Pills: Key Contraindications You Should Know

Hello, doctor. Are there any contraindications for using contraceptive pills?

Dr. Lin Wenbin reply Obstetrics and Gynecology
Individuals with a history of venous thromboembolism, cardiovascular disease, diabetes, obesity, breast cancer, pregnancy, breastfeeding, acute liver disease, migraines, prolonged bed rest, smoking (20 cigarettes per day and over the age of 35), and hypertension (blood pressure h...

Understanding Birth Control Pills: Side Effects and Fertility Concerns

Hello Doctor: I have been taking birth control pills, but later a colleague seriously told me that taking the pills has side effects and can be harmful to the body, possibly leading to infertility in the future. However, I have been taking them for several months and feel no disc...

Dr. Wei Fumao reply Obstetrics and Gynecology
Please choose a lower dose contraceptive pill. A triphasic pill is preferable, and it is best to take it for six months followed by a one-month break (to reduce excessive suppression of ovulation during the medication break).

Understanding Side Effects of Esmya Contraceptive Pills: What to Do?

Hello Doctor, I have never taken oral contraceptives before, and my menstrual cycle has been irregular since menarche. During health check-ups in high school and college, I had slightly elevated cholesterol levels. My weight is about 45 kg and my height is 156 cm. Due to contrace...

Dr. Huang Jianzhong reply Obstetrics and Gynecology
I have never taken oral contraceptives before, and my menstrual cycle has been irregular since menarche. During health check-ups in high school and college, I had slightly elevated cholesterol levels. My weight is approximately 45 kg and my height is 156 cm. Due to contraceptive ...