Sex Myths as Explained by Science

1. Men Reach Their Sexual Peak at 18, and Women Reach Theirs at 28

TRUE: With regard to their supply of sexual hormones, at least. Testosterone peaks at age 18 in men; women's estrogen hits its high point in their mid-20s. "But peak hormones don't mean peak sexual performance," says Marc Goldstein, M.D., a professor of reproductive medicine and urology at Cornell University's Weill Medical College. So feel free to try for a personal best-at any age.

2. Semen is Low-Carb

FALSE: "Semen is mostly fruit sugar [fructose] and enzymes-not low-carb," says Dr. Goldstein. Which finally explains why there's no Oral Sex Diet.

3. Masturbation Yields the Strongest Orgasm

TRUE: But it's not a hard-and-fast rule, as it were. "It depends on the individual," says Jon L. Pryor, M.D., a professor of urologic surgery at the University of Minnesota. "For some it does, but for others, there's nothing that beats good ol' intercourse."

4. The Average Erection Measures 8 Inches

FALSE: Relax, Shorty. It's closer to 6.

5. No Penis is Too Large or Too Small for Any Vagina

TRUE: But perception still wins the game in the end. "I was once at a dinner meeting with seven other sex doctors-six men and one woman," says Dr. Pryor. "The men all agreed that size doesn't matter. The woman looked at us and said, 'Think what you want. Size matters.' We all left dejected."

6. Oysters Make You Horny

FALSE: You make you horny. "There is no scientific evidence that oysters increase libido," says Dr. Pryor. "But there may be a placebo effect, so if it works, great!"

7. Green M&Ms Make You Horny

FALSE: Unless they do. Then it's true. Isn't the mind wonderful?

8. Men Think About Sex Every 7 Seconds

FALSE: That number is tossed around a lot, but the truth is that only 23 percent of men claim to fantasize frequently. But maybe the rest are just too distracted to check the clock.

9. Cutting Out Broccoli Will Make Your Semen Taste Better

TRUE: Semen is naturally bitter, and eating broccoli and drinking coffee can make it worse. A ray of hope for the Oral Sex Diet!

10. Having Sex Before an Important Event-the Big Game, the Critical Presentation-Can Ruin Your Performance in the Event

FALSE: Swiss researchers performed stress tests on people 2 and 10 hours after the subjects had had sex, and found that by 10 hours, the participants were fully recovered. There was only a small dip in performance 2 hours after sex.

11. Having Sex in Water (Swimming Pool, Hot Tub, Shower) Will Kill Sperm

TRUE: Some of your swimmers may die, but it isn't an effective method of birth control, according to Dr. Pryor. Though a hot tub can overheat your testicles and kill sperm, there should be plenty left for the egg hunt.

12. You Can Become Addicted to Web Porn

TRUE: But the risk is low. Only 1 percent of all people who check out Internet porn will become addicted. If you're sporting a ring, be careful: 38 percent of addicts are married.