29 Interesting Sex Facts that Sound Made Up But are True

Published April 12, 2017Updated November 15, 2025

From body quirks to brain chemistry, the world of sex is more unusual and crazy than people realize. Explore interesting sex facts to see just how deeply biology, psychology, and evolution converge to create a strange and surprising world of sex.

The Science of Sex

Your brain is your most powerful sex organ.
Many researchers consider the skin to be the largest sex organ and the brain to be the most powerful_[15]
Sex improves sleep and relaxation
After an orgasm, the body releases oxytocin and prolactin, promoting relaxation and deep sleep._[2]
Sex may boost your immune system.
People who are sexually active may have a more healthy immune system, greater bladder control, lower blood pressure._[18][20]
Orgasms light up the brain.
According to the Journal of Sexual Medicine, during orgasm, your brain lights up and activates regions linked to emotion, memory, and even pain relief._[24]

A foot fetish is one of the most widely reported sexual preferences

The brain science behind foot fetishes.
The area in the brain for feet and genitals are located next to each others, so it's easy for the wires to cross, potentially explaining why people have foot fetishes._[6]
Kissing can lower stress.
A passionate kiss has been associated with reducing cortisol levels and increasing feelings of connection and calm._[13]
Love, Lust, and Attraction

Your voice changes when you talk to someone you're attracted to.
Both women and men subconsciously alter pitch and tone to sound more appealing._[22]
Attraction is influenced by scent.
Humans subconsciously detect genetic differences (MHC genes) through subtle scent cues._[21]
Body and Biology of Sex

Scientists are unsure why humans have pubic hair.
Scientists theorize that the hair may help trap pheromone-rich secretions_[4]
Testosterone Peaks in the Morning
The testosterone peak makes early sex more satisfying for men._[25]
Men experience 10-12 erections per day
Several occur during the sleep to help keep penile tissue healthy._[8]

Open communication is one of the strong predictors of relationship satisfaction, emotional intimacy, and long-terms sexual health

Open communication increases intimacy
People who communicate openly about sex report higher levels of sexual and relationship satisfaction. Open communication increases intimacy, aligns expectations, reduces anxiety, and helps cope with any challenges._[16]
The orgasm gap is real.
Heterosexual women have fewer orgasms than men, bisexual women, or lesbian women._[19]
“Nipplegasm” exists.
This means that some women can orgasm through nipple stimulation._[17]
MYTH: The clitoris has over 8,000 nerve endings, twice as many as the penis.
While this number is often cited, it actually comes from bovine dissections. Human counts are not yet confirmed!_[4]
A man's testicles produce about 1,500 sperm every second.
That's over 100 million sperm per day, or a 1 trillion during a lifetime. However, most will never be used._[9]
The average male orgasm lasts about 6 seconds. The average female orgasm lasts about 20.
Nature apparently has a favorite._[9]
Sexual Health and Benefits

Sex can strengthen your heart.
Regular sex balances hormones, improves circulation, and can decrease the risk of heart disease._[4]
Orgasms can relieve menstrual cycles.
Muscle contractions during orgasm help relax the uterus, which eases pain naturally._[2]
Unusual Facts about Human Sexuality
The fear of having, seeing, or thinking about an erection is called ithyphallophobia.
Though rare, it can cause severe anxiety and avoidance of all things sex._[5]
Some animals have far stranger sex lives than humans.
Bedbugs simply stab females in the abdomen with their penis, while a male anglerfish actually fuses his body to the female's body._[1]

Scientists believe that sexually induced sneezing is more common than people think

Sex, and even thinking about sex, can trigger sneezing in some people.
Scientists think it's because there is crossed nerve signals in the automatic nervous system._[7]
People don't think about sex every 7 seconds.
Contrary to popular belief, people do not think about sex every 7 seconds. On average, men think about sex 1-2 times per hour. Women think about it slightly less._[4]
Testicles hang unevenly for protection and temperature regulation.
One testicle normally hangs lower so that they don't collide during movement and to help regulate the temperature of the sperm. Ideal sperm production requires a temperature slightly below body temperature._[23]
Culture, Evolution, and Global Trends

Intercourse has many nicknames
Sex nicknames include “afternoon delight,” “dancing the mattress,” “rumbusticating,” “shtupping,” “spearing the bearded clam,” "horizontal refreshment," and “testing the mattress._[11][12]
Here are the five countries with the lowest number sexual partners:
Indonesia (5.1), Hong Kong (3.7), Vietnam (3.2), China (3.1), and India (3.0)._[3]
The top five countries with the most average sexual partners:
1) Turkey (14.5); 2) Australia (13.3); 3) New Zealand (13.2); 4) Iceland (13); and 5) South Africa (12.5). The United States ranks 12th in the world with 10.7 partners._[3]
Sex hasn’t always been associated with sin and guilt.
Pre-Christian religions often regarded sex as a celebration and as a form of worship. Sex was seen as mirroring the sensual power of the Gods._[14]

Pre-Christian religions often regarded sex as a celebration

Upper Paleolithic art dating back 30,000 years depicts people using dildos to pleasure themselves and others.
That means mankind invented sex toys long before the wheel._[10]