IGF-1 (beard growth promoter)
The hormone the beard-gummy grifters won't explain: IGF-1 primes the follicle, DHT does the talking.
Grounded in the research on Insulin-like growth factor 1
1. What it actually is
Insulin-like growth factor 1 (IGF-1, somatomedin C) is a 70-amino-acid peptide hormone, structurally close to insulin, encoded by the IGF1 gene. Growth hormone (GH) from the pituitary tells your liver to pump it out, and most of the IGF-1 in your blood is liver-made. It's the actual workhorse behind a lot of GH's 'growth' rep. Not a supplement you can swallow and not a vitamin. It's a signal.
2. The mechanism nobody on TikTok mentions
IGF-1 binds the IGF-1 receptor (a tyrosine kinase) and fires the PI3K/Akt and MAPK pathways: it pushes cells to grow and divide and blocks apoptosis (programmed cell death). In the hair follicle it acts on the dermal papilla, the cluster of cells at the follicle base that controls the hair cycle. More IGF-1 signaling = longer anagen (growth phase), bigger follicle, thicker shaft. It's a growth-promoter, not the on-switch for where hair appears.