Hi, Welcome to HealthcareMagic. The size of an erect penis usually over 2 inches is normal. No scientific research supports the use of any non-surgical method to enlarge the penis, and no reputable medical society endorses penis surgery for purely cosmetic reasons. The techniques you see advertised can damage your penis, and some may even cause erectile dysfunction (impotence), so think twice before trying any of them. The most effective solution may be as easy as open communication with your partner, or may be to seek the advice of a urologist or sexual health expert. In that case if the size of penis is less, micropenis can be ruled out. It can be due to testosterone deficiency, pituitary hormone deficiency, hypergonadotropic hypogonadism and growth hormone deficiency. Various investigations required are chromosomal studies, hormone studies like Gonadotropins (LH and FSH), Testosterone and DHT levels, thyroid hormone levels, ultrasonography and testosterone therapy. Please get these investigations done. Treatment will depend on diagnosis. Hope it helps you. Regards.