| Name | LH-RH test (GnRH test) |
| Specimen requirements | serum |
| Procedure remarks | Measure the baseline value; take 2 blood samples at an interval of approx. 15 min, followed by IM administration of 5000 units of HCG as bolus (e.g. Pregnesin or Predalone), slow IV administration of LH-RH (e.g. Ferring), relefact (e.g. from Höchst), GnRH (e.g. from Serono): Women: 25 µg, Men: 100 µg Blood samples taken: LH: Women: 25 min, Men: 30 min, FSH: Women: 45 min, Men: 30 min Note: Discontinue sexual hormone substitution at least 3 weeks beforehand. |
| Clinical utility | hypogonadism, ovarian insufficiency, amenorrhoea, severe oligomenorrhoea, late puberty, anterior hypophyseal lobe insufficiency; differentiation between a secondary (hypophyseal) and a tertiary (hypothalmic) cause. suspicions of testicular insufficiency, ovarian insufficiency |