Abstract
An analogue of luteinising-hormone-releasing hormone ([D-Leu-6, desGly- NH
2-10]-L.H.R.H.-ethylamide) was administered by mouth to thirteen healthy men. In eight men 10 mg of this superactive L.H.R.H. analogue significantly increased mean plasma-L.H. within 45 minutes of administration. This increase was sustained for more than 5 hours. 2 mg of the analogue did not significantly increase plasma-gonadotrophin concentrations in the five men to whom this smaller dose was given. Oral administration of some L.H.R.H. analogues would seem to be effective in releasing L.H. in man.