What factors affect the size of a penis? Is penis size genetic? Do other factors affect size?
The penis grows gradually after birth. However, the most significant growth occurs during puberty, or between 12-16 years of age.
A penis typically reaches its maximum length and girth when a person is 18 or 19 years old. However, some people experience penile growth well into their early 20s.
Average penis size
According to a 2014 review of 20 studies with a total of 15,521 males, the average penis length is:
— 9.16 centimeters (cm) or 3.6 inches (in) when flaccid
— 13.24 cm or 5.2 in when stretched in a flaccid state
— 13.12 cm or 5.17 in when erect
The average penis circumference is:
— 9.31 cm or 3.6 in when flaccid
— 11.66 cm or 4.6 in when erect
What factors affect the size of a penis?
Genetics is the single most important predictor of your penis size. Besides such macro factors, these micro factors could influence your penis size.
Genetics
Genetics is the most important predictor of your penis size. Just as your eye and skin color are determined by hereditary factors, so is your penis size. Studies have found another factor to be a strong indicator of flaccid penis size — height. Not surprisingly, your height is also determined by your genetics.
Hormones
Hormones play a role in your penis size from the start. Androgens determine penis size during early fetal development. Throughout puberty, testosterone and growth hormone regulate penis growth, including length and girth.
Environment
Environmental pollutants, such as pesticides, plasticizers, and other chemicals, may have a negative effect on penis size. These chemicals may act as endocrine disruptors and impact gene and hormone expression.
A 2016 study suggests that prenatal exposure to chemicals, such as phthalates, negatively impacts the genital development of male newborns.
A 2019 study also suggests that epigenetic-associated dietary influences may slow genital progression in adolescent boys.
Nutrition
Malnourishment during pregnancy could prevent the fetal penis from growing properly. Similarly, teens who don't get enough nutrition at the time of their puberty could have delayed puberty, a condition known to cause smaller testicles and penises.
Supra-Pubic Fat
Genetics are the strongest predictors of penis size. However, factors such as body fat and the presence or absence of pubic hair can make the penis appear larger or smaller without affecting its true size.
Weather
When exposed to cold temperatures, the blood vessels in the penis constrict. This physiological reaction causes the penis to shrink temporarily.
Factors that do not affect size
The following do not affect penis size or appearance:
— Shoe size
— Height
— Masturbation
Risks of trying to increase size
The penis enlargement or male enhancement industry claims that enlargement procedures, vacuum devices, pills, and creams increase penis size. However, there is limited research on many of these methods, and they may come with serious risks.
The American Urological Association states that there is not enough high-quality evidence to support the safety or efficacy of penile augmentation surgery.
Potential risks of trying to increase penis size include:
— Swelling, infection, or scarring after surgery
— Damage due to overusing a vacuum pump or stretching devices
— Contact dermatitis that topical products may trigger
— Allergic reactions to ingredients in pills
— Erectile dysfunction
Sources: webmd, medicalnewstoday