It has been on the market for over a century, and its major chemical ingredient has been in medical use for more than 3,500 years, yet it's still the subject of intense scientific study and controversy. About 40,000 tons are produced every year worldwide, and over 50 million Americans take it regularly, but many who should use it don't do so. It costs only a few pennies a day, but it's often overlooked in favor of much more expensive drugs that have similar benefits but more side effects. It earned its good name from its ability to relieve pain, soothe ...

Prostate cancer is an important disease; in fact, it's the most common internal malignancy in American men. Prostate cancer is a variable disease; many cases are slow growing, even harmless, but some cases are aggressive and even lethal. And it's a puzzling disease; some cases are passed down from father to son, but most occur without apparent rhyme or reason.

Important, variable, and puzzling — it is no wonder that men pay attention when research reports that common dietary elements appear to reduce risk. Two studies have attracted a lot of press; both contain surprising information, but to understand what ...

Q. My doctor just started me on Zocor to lower my cholesterol. I have had just one side effect, forgetfulness. It's not as bad as it sounds, since my memory remains excellent, except that I often forget to take my pill in the evening. So I'd like to know if it would be okay for me to take Zocor in the morning with my other pills, which I never forget.

A. Many people have trouble remembering to take medications; drugs that are administered several times during the day are particularly troublesome.

Like the other statin drugs, simvastatin (Zocor, generic) reduces ...

Q. I am a 64-year-old man. Aside from diabetes, I've been healthy and until now, the only prescription I've taken is insulin. But I've been having trouble with erections, and my doctor just gave me a prescription for Viagra. He also told me to be careful about using other drugs with Viagra but didn't give me a list. Can you please fill me in?

A. Viagra (sildenafil) is one of three widely used medications for erectile dysfunction; the others are Levitra (vardenafil) and Cialis (tadalafil). Although you'd never know it from their advertisements, the three medications are closely related and ...