This invention is directed to compounds of the formula ##STR1## and the pharmaceutically-acceptable salts thereof, where the substituents are as defined in the Specification, which are 
growth hormone secretogogues and which increase the level of endogenous 
growth hormone. The compounds of this invention are useful for the treatment and prevention of 
osteoporosis and / or frailty, congestive 
heart failure, frailty associated with aging, 
obesity; accelerating 
bone fracture repair, attenuating 
protein catabolic response after a major operation, reducing 
cachexia and 
protein loss due to chronic illness, accelerating 
wound healing, or accelerating the 
recovery of burn patients or patients having undergone major 
surgery; improving 
muscle strength, mobility, maintenance of 
skin thickness, metabolic 
homeostasis or renal 
homeostasis. The compounds of the present invention are also useful in treating 
osteoporosis and / or frailty when used in combination with: a 
bisphosphonate compound such as alendronate; 
estrogen, premarin, and optionally progesterone; an 
estrogen agonist or 
antagonist; or 
calcitonin, and pharmaceutical compositions useful therefor. Further, the present invention is directed to pharmaceutical compositions useful for increasing the endogenous production or release of 
growth hormone in a human or other animal which comprises an effective amount of a compound of the present invention and a 
growth hormone secretagogue selected from GHRP-6, Hexarelin, GHRP-1, growth 
hormone releasing factor (GRF), IGF-1, IGF-2 or B-HT920. The invention is also directed to intermediates useful in the preparation of compounds of Formula I.