Medical therapy of endometriosis needs to be revised after our new understanding of peritoneal fluid concentrations of estrogens and progesterone. All medical therapy mainly act by decreasing estrogen concentrations

Some 30% of women do not respond to medical treatment, since some endometriosis lesions do not require estrogens and since lesions are heterogeneous,

Oestro-progestins and progesterone probably strongly prevent recurrences.

Indications for Medical Treatment of Endometriosis


  • Medical treatment without a diagnostic laparoscopy should never be done since the diagnosis is not made.
  • Medical therapy because surgery has been incomplete because of a lack of experience
  • Medical treatment before surgery should rarely be done since smaller lesions risk to be missed.


  • Medical therapy for infertility and endometriosis



  • Medical treatment to prevent recurrences Although few solid data exist we believe that oral contraception might reduce recurrences of typical endometriosis
  • Medical treatment to prevent progression : no data.

Side effects

  • Progestins induce weight gain,
  • GNRH induce osteoporosis

Results and safety of medical therapy

  • Medical therapy decreases pain, but not in some 30%
  • Medical therapy is considered safe but
    • some deep endometriosis lesions can induce severe complications during pregnancy such as bowel obstructions, and bowel or bladder perforations
    • during medical therapy some lesions continue to grow


Types of Medical Therapy for Endometriosis

Medical menopause: GnRH agonists (or antagonists)

GnRH agonists (eg Lupron Depot, Synarel, Zoladex, Decapeptyl) suppress ovarian function, resulting in artificial menopause with all consequences such as hot flushes, night sweats, insomnia, vaginal dryness, loss of sexual interest, and depression.
According to the FDA, LHRH agonists should not be taken for longer than six months because of the risk of osteoporosis.
Can give excellent pain relief, but the symptoms will come back after treatment has been stopped.
Can be associated with add-back therapy (small doses of estrogens) enough to prevent the worst menopause symptoms

Progestagens only and oral contraception

Progestagens (eg orgametril, lutenyl, danazol) were believed to decidualise and stop the growth of the endometrium and endometriosis
Can give pain relief, but the symptoms will come back after treatment has been stopped.
Many progestagens have androgenic side effects and cause weight gain

Experimental drugs

Anti-progestins primate experiments suggest they might be as effective as GnRH agonists without the side effects. Today no drugs are approved for endometriosis.
Aromatase inhibitors: probably only useful for lesions that produce estrogens within the lesions.
Anti-angiogenic products. Since endometriosis is associated with local angiogenesis, something we demonstrated back in 1994, this might be a logical approach in the future.
Anti-TNFa drugs This therapy has been hyped following preliminary evidence of decreasing implantation in primates. It is a typical example of how research data were overemphasized by their authors. We recently demonstrated that in women anti-TNFa is not effective for pain.

Medical therapy has strong placebo effects, as demonstrated for TNFa. In this article, we asked the question of whether medical therapy indeed does reduce pain. We wrote in the discussion,“We have scrutinized the literature on the medical treatment of endometriosis-associated pain. The evidence of efficacy may be weak as the blinding in most studies appears inadequate. Researchers and patients were able to guess whether individuals were randomized to placebo or active treatment if menstruation was prevented or if there were major side effects such as hot flushes, or recognizable physical signs, such as vaginal atrophy. In addition, conclusions are usually based on abolishing menstruation will thus, by definition, be effective in reducing dysmenorrhea. Given the strong correlation between pain symptoms, it remains uncertain whether these treatments are effective for all pain symptoms associated with endometriosis or simply dysmenorrhea alone.”

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