Reproductive Hormones During Sustained Administration of Kisspeptin

Participants will be invited to have an initial baseline study to look at the hormone levels at regular intervals over the course of a day (8hours).

Following this, on a different day, volunteers will have an infusion of kisspeptin, which will be administered by a small pump to deliver the hormone into subcutaneous tissue (fatty tissue just below the skin surface). On day 1 of the pump infusion there will be another day of regular blood sampling for 8 hours. After this the kisspeptin pump will continue and the participants will return to the research unit on day 3 for a review and a single blood test. On day 5 the participants will have a review, a blood test and the kisspeptin pump will be changed. Kisspeptin infusion will continue and on Day 8 the participant will return for another 8 hour study. At the end of this the kisspeptin pump will be removed.

The above will be repeated using either placebo (saline) or kisspeptin in doses of 0.1, 0.3 or 1.0 nmol/kg/hour during the early follicular phase of 4 separate menstrual cycles.

Inclusion criteria

• Aged 18-60 years old
• Ability to give informed consent
• Secondary hypogonadism (or healthy participant)

Exclusion criteria

• anaemia
• medical problems such as severe heart, kidney or liver disease
• blood donation in the last three months or intention to donate blood within 3 months of the end of the study
• needle phobia
• Poor venous access
• Active psychiatric illness
• Severe allergies
• Impaired ability to provide full consent to take part in the study
• Current alcohol or illicit drug dependence
• Current pregnancy or breast feeding
• Plans to conceive within 3 months of starting the study (barrier contraception must be used during and for 3 months after the end of the study)
• Arthritis or any impairment of hand coordination which would preclude using a hormone pump