Micropenis

Also known as: Microphallus, small penis

What is micropenis?

Micropenis is the medical term for a smaller than a normally formed penis (1.1 to 1.6 inches in the newborn baby). This is opposed to an “inconspicuous penis” where scar tissue, fat or loose penile skin make it appear to be smaller than normal, or “microphallus” which usually refers to a small penis with hypospadias. In addition, before puberty obese boys may have a “buried penis” which is normal in size but is pressed inward by prepubic fat.

What causes micropenis?

Micropenis can occur as an isolated abnormality or as part of a variety of other disorders. Causes include; abnormalities in certain hormones which control penis growth, including hypothalamus, pituitary, or gonadal axis, part of genetic syndromes or causes unknown.

What are the signs/symptoms of micropenis?

Other than the smaller size of the penis, a child with micropenis should be thoroughly examined for other congenital physical abnormalities.

What are micropenis care options?

Depending on the cause, testosterone or other hormones may be effective in increasing penis growth. Rarely, surgery may be considered.

Reviewed by: Jack Wolfsdorf, MD, FAAP

This page was last updated on: September 16, 2025 12:19 PM