In the short protocol the GnRH agonist is administered almost concurrently with the gonadotropins and it is also known as the Flare-up GnRH agonist protocol. The short protocol is usually selected for women with poor response to ovarian stimulation. In the short protocol:

• The administration of GnRH agonist usually starts on the 1st-2nd day of the cycle and the gonadotrophins on the 2nd-3rd day.
• It is not divided into a downregulation and stimulation phase,
• its duration is about 10-14 days in total.

In the short protocol, with the simultaneous administration of GnRH agonists and gonadotropins we are taking advantage of three stimulation signals of the gonadotropins on the ovaries in order to recruit multiple follicles and to collect more oocytes. These three "triggers" are applied by the increased endogenous FSH that normally increases in the beginning of the cycle, by the increase of endogenous FSH due to the initial stimulating effect of the GnRH agonist in the pituitary and by the exogenously administered gonadotropins via injections. Towards the last days of the short protocol, the suppressive effect of the GnRH agonist in the pituitary also takes place. Variations of the short protocol include the ultra-short and the Microflare (Microdose flare) protocols.