How do peptides stimulate hormones?

Peptides can stimulate the release of hormones by mimicking the natural signals that the body uses to trigger hormone production. For example, certain therapeutic peptides are designed to activate the release of growth hormone and insulin-like growth factor 1 (IGF-1), but they do this not by directly stimulating the growth hormone pathway, but rather by mimicking the natural signals from the hypothalamus to the pituitary gland. These peptides, known as secretagogues, are synthesized in labs and function by stimulating the release of growth hormone, which in turn stimulates the production of IGF-1.

There are two general categories of these peptides:

1. Growth Hormone-Releasing Hormone (GHRH) Peptides: They directly stimulate the release of growth hormone.
2. Growth Hormone-Releasing Peptides (GHRPs): These function slightly differently, often by mimicking or stimulating the release of ghrelin, which can also influence growth hormone levels.

Both types of peptides interact with the pituitary gland to increase hormone levels, but they do so through different mechanisms, making this aspect of peptide therapeutics complex and requiring careful consideration in their use due to the broad range of effects they might have 1 2.