In androgenetic alopecia (AGA) aka pattern hair loss, another set of key gender-specific distinctions are the triggers governing when the disorder manifests.   In both males and females there are three factors which must be in place.  First, genetics.  One must have a genetic predisposition for hair loss.  Second, age.  In other words, nine year old children do not typically suffer from pattern hair loss.  In males, AGA usually begins in one’s mid to late twenties.  In females, the age of onset often corresponds to menopause – beginning shortly before, during or thereafter.  The third factor is hormonal.  One must have circulating androgen hormones which trigger the onset and progression of the disease phenotype.  In the absence of these hormones AGA will not occur.  More on this in our next blog post.