Main Page | See live article | Alphabetical index Leptin is a hormone secreted by full fat cells. The hypothalamus detects its presence and indicates that fat storage is plentiful. Leptin works by inhibiting the actions of neuropeptide Y, which is the most potent appetite stimulant yet discovered. This article is a stub. You can help Wikipedia by fixing it. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.