Where did you learn that gamma linoleic acid grows our dicks during puberty?
I know that gamma linoleic acid (an efa) is used as a substrate for the production of certain prostaglandins such as PGE-1, which acts as a vasodilator and with proper levels of PGE-2 can relax tissues for a more accomodating stretch, namely child birth. Definatly helpful for maintaining proper erectile function.
I have read the gamma linoleic acid is also an effective 5-alpha reductase inhibitor, which is the enzyme that is responsible for the reduction of testosterone into dihydrotestosterone, which is often cited in studies on penis development, function and growth, especially during puberty.
To the point of your question, yes I use GLA supplements approx, once or twice per week to avoid the potential of a spillover effect on prostaglandin production. I usually use EPA for my efa source for producing PGE-1. I feel if you take the proper dosage for your body you may notice an increase in certain aspects of erectile function...but it is no "magic bullet".