Testosterone is a hormone that acts as the primary sex hormone in men. It is produced by the male testicles and the female ovaries. Testosterone levels in men increase during and after puberty, dropping again after about age 40. Testosterone causes the deeper voice, bigger muscles, body hair, and other primarily male features. Follow the links below to find WebMD's comprehensive coverage about what testosterone is, what it does in the body, what levels are normal, and much more.
Low Testosterone and Your Sex Drive
Some men experience a low sex drive and erectile dysfunction because of declining testosterone levels. WebMD explains the connection between hormones and sex drive.
Low Testosterone and Your Health
Low testosterone is associated with other medical conditions, such as diabetes, obesity, heart disease, depression, and erectile dysfunction. Find out more about the link and the questions that remain.
Testosterone Replacement Therapy
When should you treat low testosterone? WebMD explains the benefits, risks, and side effects of testosterone replacement therapy.
Erectile Dysfunction and Testosterone Replacement Therapy
WebMD explains how testosterone replacement therapy can be used to treat erectile dysfunction.
Low testosterone? There’s a fix for that … maybe.
Testosterone therapy is all the rage, but it’s important to know when you really need it.
How to Balance Low T
Do you have low T? If so, what can you do about it?
How to Talk to Your Doctor About Low Testosterone
Low testosterone is a natural part of aging, but it can still be embarrassing. Here’s how to bring it up with your doctor and get help.
Low Testosterone Explained
It’s natural for testosterone levels to decline as men age, but sometimes low testosterone can cause symptoms ranging from low sex drive to depression. This article explains what happens when you have low testosterone and what the options are for treatment.
Slideshows & Images
Slideshow: A Visual Guide to Low Testosterone
A dip in a man's sex drive can be a symptom of low testosterone -- or a normal part of aging. See the symptoms and treatments for 'Low T' in this slideshow .
Slideshow: Natural Ways to Boost Testosterone
Find out what you can do to raise your testosterone levels naturally, including changes to your diet and lifestyle.
The Truth About Testosterone Quiz: Low Testosterone and Aging in Men
Take this quiz and see how much you know about aging and low testosterone in men. What do you know about low T and how it can affect you as you get older?
Quiz: Things Men Can Stop Worrying About in Bed
Are you concerned about bedroom “problems” when you don’t really need to be? Take this WebMD quiz to throw back the covers and expose the truth.
Manly Myths Quiz: The Truth About Men’s Health
Think you know the difference between myth and reality when it comes to men’s health issues? Take this quiz and find out.