Protásio Alves, MD. Associate Professor of the Surgery-Urology at the State University Rio Grande do Sul.

Cláudio Lima, MD, M.A. in Surgery (Urology) by the State University Rio Grande do Sul (UFRGS).

The concern with penis size is common amidst men. Such anxiety can occur in childhood, adolescence, or adulthood. Boys often compare the size of their penis to the others. Jokes and jesting arise from such comparisons. However, the situation changes when sexual activity begins.

Many men, despite having a penis of normal size, find it small for a number of reasons:

The others' penises are bigger.
This situation is quite common and often lacks medical basis. The patients complain about the length of their organ even with normal erection and vaginal penetration.
Obese patients complain about having a short penis.
This situation stems from the embedment of the penis into the fat on the pubis, which makes the organ looks small.
Tall stature and non-proportional penis.
Although there's some correlation between the patient's stature and his penis size, a wide range of lengths is found. Short men may have bigger penises than tall men, and vice-versa.
Penis flaccidity and erection.
By and large, patients are most concerned with the size of their penis in flaccid state, when usually they compare their penis size with other men's. Many don't know the length of their erect penis or how many additional inches are added. What many men forget is that size must be accompanied by an effective erection that ensures vaginal penetration.

What's a normal penis?

Disregarding the anatomical aspects of normality, a flaccid penis is as long as 5 cm (1.97 inches) to 10 cm (3.94 inches). The size in flaccid state doesn't determine the size during erection. The measure is taken from the point where the penis meets the body (not the skin) to the glans end. If we stretch it manually, the penis will gain from 2 cm (0.78 inches) to 5 cm (1.97 inches). Master and Johnson (1966) observed that an erect penis measures from 12.5 (4.92 inches) to 17.5 cm (6.89 inches). A newly born baby has an average length of 3.75 cm (1.47 inches).

What's an abnormal penis?

There's no universally accepted definition. A flaccid penis shorter than 4 cm (1.57 inches) or an erect penis shorter than 7.5 cm (2.95 inches) must be considered small. Nevertheless, we find patients close to these values who present a good erection and no complaints in their sexual relationship.

What are the causes of small penis?

Hormonal causes stemming from testicle or hypophysis dysfunction may interfere with the development of the penis as well as the entire male genitalia. Amidst these cases we may find disorders ranging from micropenis to ambiguous genitalia. The penis may remain small as a consequence of traumas, burns or acquired diseases (Peyronie's disease). Usually, these causes are rare. Most frequently, the patient is not satisfied with his penis size, even if the physician finds no anomaly.


The patient must be thoroughly examined, including volume and presence of the testicles, presence and localization of pubic hair, and other secondary sexual features. Should the penis be considered of normal size by the physician, the patient will have to be evaluated by a sexologist, psychologist or psychiatrist so that the actual cause of the complaint is investigated. If the penis is considered small and hormonal alterations are detected, testosterone replacement is indicated.

Non-surgical treatments with vacuum pumps, stretching devices, electromagnetic stimulation devices, and weights deliver no lasting satisfactory response. Surgical treatment involves an incision at the suspensory ligaments of the penis, fat injection into the penis (girth enlargement) or use of skin grafts from thighs or buttocks. Such treatments aren't exempt of complications, and some of these may be severe, such as flap necrosis, fat reabsorption, patient frustration. Additionally, the outcomes of these treatments are poorly known in medical literature.


Unfortunately, many unethical professionals take advantage of the patients' anxiety and doubts, indicating, without any criteria whatsoever, treatments whose main goal is to take the patient's money rather than providing scientific guidance. Patients with doubts about their penis size must look for a qualified professional that will evaluate the situation, possibly entailing some multi-disciplinary advice from a sexologist or psychologist.

Questions you can ask your doctor

How can I know if my penis is normal?

Is there any safe way to enlarge my penis in case I'm not satisfied with its size?