My 11y old son's penis is 1.5' spl. his 7y brother penis is bigger and i'm concerned. he is still pre pub, shld we see a doc to check for testo level?

Puberty: In boys, or girls, is a stage, not an incident, penile and testicles size are part of evaluation for what's known as Tanner staging for pubertal growth and maturity, taking into account other parameters. Each individual is different, you have the right to be concerned and compare the siblings though.You may want to start with your pediatrician for evaluation and possible referral to endocrinology