11 February 2004

Hormonal methods

These include oral contraceptives, hormonal injections, implants and vaginal rings.

  • These are contraceptives for women and include oral contraceptives, commonly known as the "pill", as well as hormonal injections, implants and vaginal rings, all containing synthetic hormones. Their method of action is to stop the ovaries from releasing an egg each month (ovulation) and/or to keep the cervical mucus thick so that sperms cannot easily pass through it.
  • Oral contraceptives are taken according to a prescribed daily schedule. Injectable contraceptives are given as intramuscular injection and prevent pregnancy for two or three months. Implants and vaginal rings, which are not readily available in South Africa, prevent pregnancy by delivering contraceptive hormones to the body from their site of application. Implants are small, rubber-like rods placed under the skin of the arm, while vaginal rings are placed into the vagina.
  • Hormonal methods require visiting a doctor for a prescription, injection, or placement of implants/rings.

Oral contraceptives (the "pill")

  • Available as combination of oestrogen and progestogen in dose regimens that suppress ovulation, or as progestogen-only pill that thickens the cervical mucus.
  • Highly effective if taken consistently, preferably at the same time each day. If a pill is missed or vomiting occurs soon after taking the pill, another form of contraception until the onset of the next menstrual period should be used.
  • Certain drugs may cause the pill to become less effective. This is the reason why a doctor needs to be consulted for the prescription. The doctor will ask about any medication used and will find out whether there are any contraindications for the pill.
  • An oestrogen containing pill can suppress or diminish milk production and is not advised to breast feeding mothers. The hormones are also excreted in the breast milk and can cause side-effects in the newborn baby.
  • If a woman wishes to have a baby, she should switch from the pill to another form of contraception (for example barrier method) three months before planning to conceive. The chance to fall pregnant soon is greater after discontinuing barrier methods than after stopping the pill.
  • Using the pill carries a slight health risk which increases with age and smoking. Oral contraception is usually not recommended for women over 45, or those over 35 who smoke. Women suffering from cardiac disease, thrombosis (blood clot formation in veins), breast cancer, tumours of the liver or endometrial carcinoma (cancer of the lining inside the womb) are also advised against the pill. A further, relative contraindication exists for women with poorly controlled diabetes, obesity or gall bladder problems.
  • Oral antibiotics may decrease effectiveness - a backup contraception method should be used while taking antibiotics until the next menstrual period following the completion of the antibiotic.
  • Women who experience unpleasant side-effects on one type of pill can usually adjust to another. When starting the pill, communication with the doctor needs to be maintained for optimal matching of the type of oral contraceptive.
  • Effectiveness: If the combination pill is correctly used, the Pearl Index is less than 1.
  • Advantages:
    • Very effective in preventing conception.
    • Is used independently from sexual intercourse.
    • Can make periods more regular.
    • Less: acne, iron deficiency anaemia, premenstrual tension, dysmenorrhoea (period pain), rheumatoid arthritis.
    • Reduces risk of: ovarian cancer, non-cancerous breast tumours (cysts, benign dysplasia). The stronger progestogenic pills have a protective effect against the development of endometrial (uterine) cancer.
    • Reduces risk of ectopic pregnancies. This potentially life-threatening condition occurs when the fertilised egg implants and begins developing outside the uterus - usually in the fallopian tubes.
    • Reduces risk of developing pelvic inflammatory disease (PID).
  • Disadvantages:
    Oestrogenic effects
    • Breast tenderness due to fluid retention. This improves after a few months.
    • Nausea. This also improves after a few months.
    • Vaginal candida infection. This used to be more common with pills having a higher oestrogen content.
    • Pigmentation in the face (chloasma). This is rare and improves after stopping the pill.

    Progestogenic effects
    • Acne or oily skin. This is due to progestogens with an androgenic (male-hormonal) effect.
    • Weight gain. Due to increased appetite caused by some progestogens.
    • Dyspareunia (painful sexual intercourse). Due to dryness of the vagina.
    • Headache. This may be due to progestogen withdrawal during the pill-free days.
    • Loss of libido (urge to be sexually active). This is very rare.

The progestogen-only pill ('mini-pill')

  • Contains a progestogen and no oestrogen - alternative for women who desire contraception in pill form but are sensitive to oestrogen, or are breast feeding.
  • Should be taken daily like combined oral contraceptives but at exactly the same time each day.
  • Thickens the cervical mucus to prevent sperms from reaching the egg, changes the motility of the fallopian tubes to interfere with fertilisation, and makes the uterine lining less receptive for implantation should an egg become fertilised.
  • Effectiveness: A Pearl Index of 2 which means a slightly higher risk for pregnancy compared to the combination pill.
  • Advantages
    • No oestrogen - suitable for those unable to take the combined pill because of adverse side-effects or personal medical history.
    • May decrease risk of endometrial cancer and PID.
    • Does not increase risk of heart disease (blood clots).
    • Women who are advised to stop taking the combined pill at a certain age (for example, if they smoke) can safely use the progestogen-only pill.
    • Can be used by diabetics - does not affect blood sugar levels.
    • Can be used during breast feeding - no effect on the baby or milk production. Together with the contraceptive effect of breast feeding, the prevention of pregnancy comes close to 100%.
    • No delay in future fertility - it is possible to become pregnant very soon after stopping this type of pill.
  • Disadvantages
    • Requires strict pill-taking routine: This pill needs to be taken at the same time each day and ideally not less than three hours before intercourse because it takes two hours for the pill to be effective on the cervical mucus.
    • Some women experience scanty, irregular periods.
    • Persistent spotting is another possible symptom, but this should resolve after a few months' usage or by switching brands.
    • Although the incidence of ectopic pregnancy is extremely low, the ectopic/intrauterine ratio is higher than with combined oral contraceptives or injectable progestogens.

When to call a doctor:
Women taking oral contraceptives should contact their doctor immediately when suffering any of the following conditions:

  • Severe or sudden onset of abnormal bleeding
  • Severe headaches
  • Sharp, stabbing pains in the chest
  • Blood present in sputum
  • Blurred vision
  • Muscle weakness
  • Severe abdominal cramping

Injectable contraception

  • Progestogen injection deep into muscular tissue of buttocks or upper arm.
  • Although similar to the 'progestogen-only pill' regarding the effect on cervical mucus, tubal motility and endometrium, the additional effect of the injectables is inhibition of ovulation due to the larger dose of progestogen.
  • Single injection provides contraceptive protection either for 12 weeks (Depo- Provera®, Petogen®) or for 8 weeks (Nur-Isterate®).
  • Benefits similar to mini-pill. Side-effects are also similar and can include irregular periods, weight gain, and breast tenderness. Most women develop amenorrhoea (no periods) and need to be adequately informed about this beforehand.
  • Advantages:
    • Extremely effective (99%) as long as injection is repeated at the correct intervals.
    • Allows contraception independent of sexual intercourse.
    • Does not depend on high level of user compliance.
    • Prevents ovulation - reduces risk of ectopic pregnancies.
    • Reduces risk of ovarian cysts.
    • Can be safely used while breast feeding.
    • No oestrogen-related side-effects - mainly benefits women unable to take oestrogen, or those over the age 35 who smoke.
    • No effect on blood pressure and clotting. Does not contribute towards developing thrombosis, and may be used under medical supervision by patients with hypertension, previous thromboembolism, cardiac disease, diabetes and obesity.
  • Disadvantages
    • Longterm side-effects. Women who suffer side-effects may need to endure them for the duration of the contraceptive's action.
    • Several women may gain weight when first using this method, although this usually stabilises.
    • Effectiveness may be impaired by certain medication (anticonvulsants, rifampicin, meprobamate) and also by alcohol. The doctor may advise to shorten the interval between injections.
    • Becoming pregnant could be delayed by six months to a year after stopping the injectable. It should not be the first choice of contraception if a pregnancy is planned fairly soon.
    • Can cause menstrual irregularities which can be treated with oestrogen containing tablets.
    • Painful intercourse may occur because of a dry vagina which can be treated with oestrogen cream.


None of the implants are available in South Africa at present. Norplant®, which was available for a short time and then withdrawn from the market, consisted of 3 cm long silastic rods which were surgically implanted under the skin of the upper arm. Six rods protected against pregnancy for up to five years by steadily releasing a contraceptive hormone (levonorgestrel). A newer single-rod device (Implanon®) may become available containing a contraceptive hormone (3-keto-desogestrel) which is slowly released over three years.
  • Advantages
    • Highly effective, reversible contraception.
    • Needs to be administered only after long intervals (three and five years).
    • Does not depend on high level of user compliance.
    • Return of fertility is quick after removal of implant.
    • Financial cost may be less than buying oral contraceptives every month over the same time period.
  • Disadvantages
    • Insertion requires a small surgical procedure under local analgesia by a skilled health professional trained in the technique.
    • May cause irregular bleeding.
    • Possible removal problems.

Read more:
The injectable contraceptive debate
Any questions? Ask our sexologist


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