However, the ability of IGF-1 to stimulate proteoglycan synthesis in chondrocyte decreases with the age of the donor increasing [39]
Katz LE, Ferry RJ, Stanley CA, Collett-Solberg PF, Baker L, Cohen P: Suppression of insulin oversecretion by subcutaneous recombinant human insulin-like growth factor I in children with congenital hyperinsulinism due to defective beta-cell sulfonylurea receptor
By week three or four, most people stabilize and stop noticing a difference
Furthermore, an animal study suggests it may be more effective than NAC for acetaminophen toxicity if the treatment is delayed (in a mouse model, it was effective when administered up to 24 hours after overdose) (Hau 2010)
Visible Improvement Phase: 4 to 8 Weeks This is when most patients start noticing clearer and brighter skin