They are hormonal contraceptive methods that are administered by intramuscular injection every month or every 3 months depending on the presentation. They have the advantage of being involuntary and easy to handle, preserving the privacy of the contraceptive method especially if the user is scrupulous in this regard. In both cases there is the problem that once injected there is no way to remove it from the body and the total metabolism of the drug must be expected: this is a very annoying problem in cases of allergies, headaches, depression, etc.

What are the options for injectable contraceptives?

In Venezuela and most of the world there are only two injectable contraceptive presentations, since they are only two and have no competition I will mention their trade names:

Depo-Provera® (Pfizer Laboratories): Medroxyprogesterone acetate in oily vehicle. Preparation exclusively on the basis of progestogens.

Mesigyna® (Schering Laboratories): Estradiol Valerate + Norethisterone Enanthate. Preparation based on estrogens and progestogens.

Depo-Provera

WARNING: According to official sources (Pfizer and FDA) the use of Depo-Provera for more than 2 years is not recommended as long-term use is associated with bone mineral loss (calcium) and non-reversible risk of osteoporosis.

A recent study in the Journal of Adolescent Health 45 (4), 423-5 (Oct 2009) reports that its use in adolescents promotes the accumulation of body fat while decreasing lean mass.

Mechanisms of action: Inhibition of ovulation, endometrial atrophy, thick cervical mucus, is not abortive.

Advantages of using Depo-Provera

• The Depo-Provera has a long history of use and safety proven
• It consists of the intramuscular application of 150 mg of the medicine every 3 months. From the first year of use, 66% of patients will stop seeing their menstruation, which in no way affects health
• As a contraceptive method it is reversible and extremely effective, 99.7% safety, comparable with surgical sterilization of fallopian tubes
• It can be used in cases of diseases such as endometriosis and premalignant lesions of the endometrium
• Apparently it has very little relation to breast cancer
• It can be used during breastfeeding, it is very economical.
• The injection does not hurt much when it is placed correctly in the gluteal region

Disadvantages of using Depo-Provera

• Short-term osteoporosis (more than 2 years of use)
• The injected drug can not be withdrawn from the body in the event of adverse effects
• The patient requires several months after the last injection to resume her fertility, cumulative effect
• Irregular menstrual bleeding, amenorrhea
• Depression, vaginal dryness, weight gain, fluid retention
• Ovarian cysts
• Fear, pain or local complications associated with injections

My thoughts on Depo-Provera

I prefer other, safer contraceptive methods with a quick and predictable fertility return. I limit their use due to osteoporosis and delayed fertility.

I use it in very particular situations, especially if there are other treatable conditions (endometriosis, endometrial hyperplasia) in which Depo-Provera has been shown to be very effective and in unreliable patients, regarding their contraception, in the early postpartum period when they exist conditions that contraindicate a very close or immediate pregnancy

When it is considered that the method is functional?

I recommend taking care of another method (condoms) until 15 days after placing the medication to increase the range of safety (although the laboratory refers to safety from the first week of use).

Time of allowed use and return of fertility

Must be used less than two years due to risk of osteoporosis. Return of fertility may take months after the last dose

Mesigyna

Mesigyna is a relatively new contraceptive in the market and consists of the intramuscular application of a medicine ampoule every month, the same day of each month.

Mechanisms of action: Inhibition of ovulation, thick cervical mucus, endometrial atrophy, non-abortive

Advantages of using Mesigyna

• As a contraceptive method is highly effective, at least 99% safety, comparable to the use of oral hormonal contraceptives, or better.
• Because it contains estrogens and progestogens, it allows maintenance of the monthly menstrual bleeding pattern with very few cases of amenorrhea.
• Its monthly injection makes its use very simple, especially attractive in adolescents and people who forget to take their “pills” every day.
• It is reversible. Return to fertility 1 or 2 months after the last application
• Less menstrual pain and amount / days of bleeding.
• Decreases the risk of ovarian and endometrial cancer. It prevents appearance and / or cure ovarian cysts.
• It does not produce osteoporosis with its long-term use and can be used for many years.
• It improves and or prevents acne.
• The pre-filled syringe makes its use simple, hygienic and safe.

Disadvantages of using Mesigyna

• The injected medicine can not be withdrawn from the body in the event of adverse effects such as allergies, headache or high blood pressure.
• Irregular menstrual bleeding, amenorrhea, loss of menstrual pattern in up to 10% of users.
• Fear, pain, or local complications associated with injections.

My opinion about Mesigyna

Excellent choice for teenagers due to their discretion and ease of use. It is very comfortable, avoids “forgetting” and with them the risk of pregnancy due to human failure of the method

In professional women I have noticed little adherence to the method due to discomfort regarding the monthly injection and effects on menstrual pattern and regularity.

When is it considered that the method is functional?

I recommend usinganother method (condoms) until 15 days after placing the medication to increase the range of safety (although the laboratory refers to safety from the first week of use).

Time of allowed use and return of fertility

The time can be indefinite as long as the patient maintains an adequate gynecological control and during the aging does not appear diseases or conditions that contraindicate its use. The return to fertility occurs within the month following the culmination of the effect of the last dose of Mesigyna