A novel cyclic heptapeptide that is useful as a preadipocyte differentiation-inhibitory agent or an adipocyte fat accumulation-inhibitory agent, and the use of such agents, are provided. A novel cyclic heptapeptide represented by the following formula is provided.
wherein R is CH
3
, CH
2
CH(CH
3
)
2
, CH
2
OCH
2
C
6
H
5
, CH(OH)CH
3
, or CH
2
OH.