"Misbehaving periods" doesn't appear on any list of medication side effects, but as many women can attest, menstrual irregularities aren't uncommon when you're taking antibiotics. The culprit may not be the drugs.
The search for the perfect male contraceptive hasn't been going so well, but a clear gel that's injected into the penis once every decade or so could prevent a lot more sperm from reaching the finish line. What's the deal?
Superficially, men's bodies remain largely unaffected by their children's births, but that doesn't mean that they're untouched by parenting on a deeper level. How can childrearing affect dads' testosterone levels? And does it make them less manly?
Plenty of people cheat. Collective data on cheating behavior among married couples projects that between 20 and 40 percent of men and 20 and 35 percent of women have committed adultery against their respective spouses. Could genetics be to blame?
The how-tos of sex haven't changed much over the ages, but our understanding of what's actually happening (and why) took off during the Renaissance. How have humanity's thoughts and beliefs about sex evolved throughout history?
As science advanced from philosophy to empirical knowledge, groundbreaking discoveries -- like the five on this list -- revealed a lot about the reproductive equipment inside human bodies. Which revolutionized our understanding of sex the most?
After decades of clinical research, there's still a lot that's not known about that climactic, pleasurable sexual sensation known as an orgasm. What's the biology behind the big moment? And why do men and women experience it differently?
Contrary to popular belief, men don't think about sex every 7 seconds. But do they think about it more than women do? What do evolutionary biologists have to say about why one sex has a stronger sex drive than the other?
The advent of birth control pills not only helped some women reduce pregnancy risk, it also opened the door to greater sexual freedom. But eliminating ovulation may also affect women's sex lives in other, more subtle ways. How?
Contemporary researchers peeking into the interpersonal and neurological pathways of long-term love have uncovered a host of ingredients for making marriages work. But how many of them are within our control?
You can't neatly slice the human population into heterosexual and homosexual camps. For people who identify as asexual, sex is a moot point. But does that mean romantic relationships are completely out of the question?
As sexology has moved from surveys and self-reporting to laboratory settings, male bisexuality has been caught in the scientific crosshairs. Why do some question its legitimacy as a bona fide sexual identity?