No matter what your problem is, someone trying to sell you cell therapy will claim to be able to treat it. Want your arthritis, heart disease, menstrual cramps, infertility, cancer, herpes, lung disease, epilepsy, Down's syndrome, Parkinson's disease, or hot flashes to go away? Want sexual prowess, youthful skin, a stronger heart, or even immortality? Nothing is too much to ask.

Whether you'll get it or not is highly doubtful. What isn't doubtful is that the treatment will cost you a bundle. If you live in the United States, include travel costs in your calculations, too. Cell therapy is unapproved in the United States, though it's popular in Europe and many other countries. Ever since it was first developed in Switzerland in 1931, it has attracted throngs of the world's rich and famous, many of whom assumed that they could buy themselves eternal youth and beauty.

Conventional doctors transfer cells from healthy to sick people all the time. Think of blood transfusions, for example, or bone marrow transplants. More recently, there have been some intriguing attempts to treat diseases such as diabetes, Alzheimer's disease, and Parkinson's disease with transplanted cells from human fetuses.

In the alternative form of cell therapy, however, the transferred cells (which are usually injected into the patient) come from an animal, usually glands from sheep or pigs. Ideally, these cells are freeze-dried, sterilized, and finely filtered to prevent rejection (and, yes, the freeze-drying idea came right out of the coffee business!). Cells from the animal's liver are said to go right to the liver of a person with hepatitis, cells from the pig's gonads go right to the man's testicles to cure impotence, and so on. Meanwhile, these cells are supposedly bolstering the entire immune system. That's why some alternative practitioners use it as a "helper therapy" alongside other treatments and why others think that it may be useful in treating AIDS.

The trouble is, there's just no convincing evidence that any of this stuff works. Anecdotes and testimonials abound, some of them even from prominent scientists. But until someone does some hard-core studies, we advise you to avoid cell therapy altogether.