General Considerations
Medroxyprogesterone acetate, known as Depo-Provera, is an injectable contraceptive derived from a natural hormone, progesterone. It was synthesized in 1954 and has been used since 1960. Since April 1997, Depo-Provera has been officially approved in Canada for contraceptive use.
How it Works
Injection of the product into a muscle causes a rapid increase in progesterone levels in the blood. This concentration in the blood is enough to provide contraception for 14 weeks.
The compound acts in different ways:
- It prevents ovulation.
- It makes the lining of the uterus unable to receive a fertilized egg.
- It alters the cervical mucous.
Effectiveness
It is 99.7% effective, which is comparable to tubal ligation. In order to be effective, injections must be administered regularly every 11 to 13 weeks.
Indications
Depo-Provera is a good option, especially in the following situations :
- Repeated failure of other methods of contraception
- You are unable to tolerate contraceptive pills or they are contraindicated for you
- You frequently forget to take the pill
- You are a smoker over the age of 35
- When amenorrhea (absence of periods) can relieve menstrual pain or premenstrual tension
- When amenorrhea offers medical or hygiene advantages
- Long-term use of medications that reduce the effectiveness of contraceptive pills (e.g., some medications for epilepsy)
- Endometriosis
- Breastfeeding
Contraindications
There are two absolute contraindications for the use of Depo-Provera.
They are:
- Pregnancy
- Unexplained uterine bleeding
Do not use this method if you want to become fertile again quickly.
Route of Administration
The medication should be injected into the arm or buttock every 11 to 13 weeks.
The first injection must be administered in the first 5 days of your period in order to be effective immediately. If the injection is administered after this time, you must wait a week in order for the protection to be effective.
If an injection is administered more than 14 weeks after the previous injection, you must wait a week before protection is reinstated and use another method of contraception during this time; naturally, if you have had unprotected sex after the 14th week, you must ensure that you are not pregnant before receiving an injection of the medication. The injection may be administered by a doctor or a nurse.
Cost
An injection costs $45; however, Depo-Provera is covered by Quebec’s prescription drug insurance plan and private insurance.
Side Effects
The most common side effect is breakthrough bleeding (irregular, unpredictable bleeding that is rarely heavy). It usually disappears after a few months of use, when amenorrhea or an absence of periods begins. The method is effective, whether you bleed or not. Your menstrual cycles will return within 6 months of the final injection in most cases; however, you may not get a period for 12 to 18 months. Nevertheless, if you do not want to become pregnant, you must use another effective method of contraception from the end of the 14th week following the injection.
Weight gain is another common side effect (average of 2.5 kg for the first year of use); it results from stimulation of the appetite. However, weight loss has been seen in 20% of women. The medication may cause other side effects similar to those seen with oral contraceptives: headaches, abdominal pain or discomfort, fatigue, nausea, decrease in sex drive, breast tenderness, mood swings, and depression.
There have been no studies linking this method and breast cancer in women. Depo-Provera protects against cancer of the endometrium (inner lining of the uterus) and ovarian cancer.
Some users may experience bone loss. To avoid this side effect, physical activity, the consumption of dairy products, and smoking cessation are recommended. Please note that in a majority of women, this bone loss is completely reversible after 2 to 3 years of not receiving the injection.
Lastly, there is no benefit to limiting the number of years of use of this method if you find it perfectly satisfactory.
Future Fertility
Fertility generally returns 6 to 9 months after the last injection and coincides with a return to a normal menstrual cycle.
Sometimes, the delay may be as long as 18 months. After this time, fertility is not reduced, regardless of the number of years of use.
Conclusion
Depo-Provera is an effective, safe method of contraception that may suit many women. It is a good choice for all women with contraindications or intolerance or who simply have not been happy with other methods.
Last update : July 2014