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Adjuvant medication

Hormone administration during fertility treatment

Treatment with medication is a common component of fertility treatment. Depending on the treatment method, it may be necessary to stimulate egg ripening or treat a corpus luteum deficiency. This is why we would like to give you a brief overview of the most commonly used medication for such a stimulation cycle.

The use of hormones as an adjuvant therapy to fertility treatment is in principle risk-free, but you should talk to your doctor about any underlying diseases. You should also inform your doctor if you have a family history of thrombosis. Please also mention any concerns you may have, so that unnecessary worries can be eliminated.

Clomifen citrate

Clomifene citrate is a substance that stimulates the ripening of egg cells in the ovaries and triggers ovulation. Due to its anti-oestrogen effect, the potential side effects are similar to the typical symptoms of menopause, for example hot flushes, headaches and depression. This medication is often prescribed by general gynaecologists as a “first try”, in part as it is available in tablet form. It is often used to promote ovulation as the first line treatment for PCOS. However, clomifene should only be taken under regular monitoring, as there is a higher probability of multiple pregnancy.


The hormones FSH (follicle-stimulating hormone) and LH (luteinising hormone) stimulate the ovaries and are secreted from  the pituitary gland. Today, these substances can be injected into the subcutaneous fat tissue by the patient herself, in the form of highly purified or synthetically manufactured preparations. The dose is determined on an individual basis and the therapy is monitored using ultrasound and hormone testing.

In the case of stimulation cycles or in the context of intrauterine insemination, the dose is chosen such that no more than two follicles ripen, in order to avoid overstimulation or multiple pregnancy. For artificial fertilisation, 8-10 follicles are the aim; the dose is thus generally higher.

Side effects depend on the dosage and the ovary response with the resulting hormone levels. Occasional side effects include tiredness, mood swings, headaches and nausea as well as mild lower abdominal pain, similar to menstrual pains. With higher oestrogen levels, the risk of elevated blood pressure and thrombosis is increased.

Long-term complications have not been reported. The risk of cancer, including breast and ovarian cancer, does not seem to be increased.

GnRH antagonists

During the natural cycle, the ripening dominant follicle in particular produces oestrogens. When a specific oestrogen level is reached (which varies between individuals), the pituitary gland secretes a surge of LH, which triggers ovulation. During stimulation treatment, the threshold oestrogen level is reached very early due to the ripening of more than one follicle. In order to prevent premature ovulation, GnRH antagonists are used. This blocks the secretion of the hormones from the pituitary gland, thus suppressing ovulation.

GnRH agonists

Contrary to antagonists, which block the pituitary gland, agonists initially have the opposite effect: they stimulate the pituitary gland to suddenly release FSH and LH whereby the hormone supply is emptied. The pituitary gland is no longer able to secrete any more FSH or LH, pituitary function being effectively blocked. GnRH agonists have been used in gynaecology for much longer, primarily for treating endometriosis, as they can bring about a long-term, reversible suppression of ovarian activity. In reproductive medicine, GnRH agonists may also prevent premature ovulation in the context of ovarian stimulation.

Whichever hormone your doctor recommends, there is no evidence of long-term consequences or increased risk of cancer. Only for clomifene citrate, the duration of administration should be limited due to potential long-term effects.