If your doctor suggested that you take two different sleeping pills that have never been tested in combination, would you do it?

If she recommended an energy-booster, but you couldn’t tell from the label what was in the bottle, would you take that?

What if she told you to ingest a medication normally used on the skin – would you want to know it might cause liver failure?

You’d probably answer “No,” “No way,” and “You bet your litigious soul I would.”

But now suppose you’re prowling the aisles in the health food store looking at “natural” remedies? You might grab something and figure, “Hey, this is herbal. It must be safe.”

As a nation, we’ve gone bonkers over alternative or “complementary” medicine, including “dietary supplements,” including herbs. More than one-third of American adults now use herbs and we spend more than $3.6 billion a year for them.

But like someone hopelessly in love, we’re a bit blind. Because herbs are sold – and regulated, by the Food and Drug Administration – as supplements, we don’t think of them as drugs, though we take them to fix or prevent all manner of ills.

This suits many people just fine, including Congress, which in 1994 curbed the FDA’s power to review supplements, including herbs, before they’re marketed.

But while the body politic may like things this way, the body into which we pour these products reacts the same whether something is labelled an herb or a drug. And while many herbs are apparently safe, some – and some combinations of herbs and prescription drugs – clearly are not. Consider:

In the latest of issue of FDA Consumer magazine, the FDA published a short list of herbs it considers “possible health hazards.” One is comfrey, whose leaf and root are used externally for treating bruises but which some people are ingesting for general healing. According to the FDA, which keeps track of adverse reports on herbs and supplements, comfrey can obstruct blood flow to the liver, with possibly fatal consequences.

Varro Tyler, dean emeritus of the Purdue University School of Pharmacy and Pharmacal Sciences, puts it bluntly: “Don’t drink comfrey. . . It should be taken off the market.”

Another risky herb is the stimulant ephedra (Ma huang), which can cause high blood pressure, heart attacks, stroke, and death.

Despite the 1994 law weakening its powers, the FDA still has the authority to yank supplements, including herbs, off the market if it can prove they’re dangerous. It hasn’t done so yet with any supplement, but it’s come closest with ephedra. Last year, the agency proposed dose limits on the active ingredient in ephedra, but so far has not followed up.

Other herbs the FDA lists as dangerous include chaparral, an underground “cure” for cancer that may cause irreversible liver disease; germander, an appetite suppressant that may also cause fatal liver disease; and dieter’s teas that can cause vomiting, constipation, and possibly death.

The FDA is also worried about willow bark, which is marketed as an aspirin-free product but can cause Reye’s syndrome, a potentially fatal disease associated with aspirin use by children; and lobelia, an emetic used to induce vomiting, that may cause cause breathing problems, rapid heartbeat, and possibly coma and death.

Complicating things is the fact that many people take more than one herb simultaneously and combine herbals with prescription and over-the-counter drugs. These combinations pose serious risks, says plant medicine specialist Tyler, who detailed his concerns in September’s Prevention magazine.

For instance:

• Blood thinners. Many herbals – notably garlic, ginkgo, ginger, and feverfew – reduce the ability of the blood to clot, which can help prevent heart attacks and strokes. But if taken with over-the-counter anticlotting drugs like aspirin or prescription drugs like Coumadin, you may bleed too easily. If you’re facing surgery, you should not only stop taking mainstream anticoagulants, but the botanicals as well.

• Diuretics and laxatives. Some herbal laxatives such as senna, cascara sagrada, and aloe make you lose a lot of water and potassium. If you take these remedies for more than a few days, you may be at risk for cardiac arrhythmias. Combining these with diuretics – prescription drugs for high blood pressure – increases this risk. In fact, combining prescription digitalis with diuretics, including the herbals, could even be fatal, warns Timothy Maher, head of the division of pharmaceutical sciences at the Massachusetts College of Pharmacy.

• Sedatives and sleeping pills. Studies show that one herbal sedative, kava, is safe and effective for anxiety and, indirectly, for insomnia; another herb, valerian, works well for many people, too. But there is little data on combining these herbs with each other or with prescription sedatives, antidepressants or alcohol.

For that reason, Tyler says, it’s safest not to mix them. But Dr. Michael Jenike, associate chief of psychiatry at Massachusetts General Hospital, says some people do combine kava with Prozac-like antidepressants. “So far,” he says, “there are no apparent adverse effects, but there may be some risks we don’t know about.”

Combining kava with alcohol is risky, he says. You may become too sedated, as if you combined Valium and alcohol.

• Substances that affect blood sugar. Hundreds of herbals, including bitter melon, dandelion, and prickly pear can lower blood sugar. In theory, if you combine these with insulin, you could wind up with too low blood sugar, which can lead to coma and death. This is less likely if you monitor blood sugar closely.

• Antidepressants. Some people combine the herbal antidepressant St. John’s wort with prescription antidepressants like Prozac. Some people also use St. John’s wort with a diet drug called phentermine, an amphetamine-like stimulant. While the first combination may not be dangerous, the second, at least in theory, could be.

Like other so-called SSRI antidepressants, Prozac works by blocking reabsorption of serotonin, a neurotransmitter, by brain cells. Phentermine may increase serotonin in the blood by blocking its destruction in platelets, says Dr. Richard Wurtman, director of the MIT clinical research center and developer of Redux, a diet drug now off the market.

Last year, when the diet drug combination “fen/phen” was withdrawn from the market because of the risk of heart disease, some dieters switched to “phen-Pro,” a combination of Prozac and phentermine.

But the net effect of taking either fen-phen or phen-Pro may be the same – too much serotonin. That is believed to cause heart damage and a potentially fatal condition called primary pulmonary hypertension, says pharmacist Maher. He, with Wurtman, has shown that phentermine acts in the test tube like a class of drugs called MAO inhibitors, which boost a number of brain chemicals, including serotonin.

“If phentermine really is an MAO inhibitor, it would be potentially fatal to take with Prozac,” says MGH’s Jenike, and in theory that would hold for combining phentermine with St. John’s wort, too. So far, though, he is not convinced that phentermine is really an MAO inhibitor.

And what if St. John’s wort itself acts as both an MAO inhibitor and Prozac-like SSRI? That’s a possibility, says pharmacist Maher. If it’s true, that could make it dangerous to take with drugs like Prozac, Zoloft and Paxil and Effexor. But if St. John’s wort does act as an MAO inhibitor, “one would expect reports of adverse effects if you combined it with these prescription SSRIs,” says Jenike. So far, there have been none.

The bottom line is buyer beware. To the federal regulatory system, there’s a difference between herbs and drugs.

But to your body, there isn’t.

Supplement standards being written

Not long ago, the FDA had the power to force manufacturers of dietary supplements, including herbal remedies, to prove those products were safe.

That changed in 1994, when Congress passed the Dietary Supplement Health and Education Act.

Now a “dietary” product can remain on the market unless the FDA finds clear evidence – not mere suspicion – of harm, which means “people have to be hurt first,” says Bruce Silverglade, director of legal affairs for the Center for Science in the Public Interest, a nonprofit consumer group in Washington.

Also, the law only requires manufacturers to produce supplements in accordance with “good manufacturing practices” in the food industry. Manufacturing standards in the food industry are less stringent than those in the pharmaceutical industry. The FDA is now writing new standards for supplements.

Furthermore, before the law, all health claims on supplements – as on food – had to have FDA approval before marketing. Now, manufacturers can make “structure/function” claims without prior approval. That means they can’t say a product prevents heart disease, but they can say something vague, such as, this product “helps maintain cardiovascular function.”

The herbal industry is aware there have been quality-control problems, says Mark Blumenthal, executive director of the American Botanical Council, a nonprofit educational group based in Austin, Texas.

In fact, the council has developed a chemical analysis system to test products, he says. In one study using this system, the council found that some products that claimed to contain ginseng did not.

In August, the Los Angeles Times reported on a chemical analysis it commissioned on the herbal antidepressant, St. John’s wort: Three of 10 brands tested had no more than half the potency listed on the label, and four had less than 90 percent.

At least two companies are now beginning to analyze the ingredients listed on herbal products.

But sometimes, the problem is that herbal remedies contain adulterants that shouldn’t be there at all. In a recent issue of the New England Journal of Medicine, FDA researchers reported on two cases of serious heart problems traced to supplements contaminated with the powerful heart drug digitalis.

Like many others at midlife or beyond, Wendy Fink, a health educator in her 50s, was appalled at the way her memory kept conking out.

“I was having trouble getting words,” says Fink, who lives in Royalston. “I was feeling very stressed about this.” So she tried ginkgo, an herbal memory-booster that’s getting new respect in mainstream medicine, albeit for genuine dementia, not run-of-the-mill “senior moments.”

“It seems simplistic,” Fink says of her four-month trial of ginkgo last winter, “but my problem went away. I feel much clearer, brighter, more myself.” She has “no idea,” she adds, why the improvement has persisted although she no longer takes the ginkgo.

The fact that she can’t explain it is hardly surprising, given that there’s little evidence that ginkgo helps healthy people like Fink with age-related memory decline.

But the lack of evidence doesn’t seem to be deterring the hopeful, who last year spent $ 270 million on ginkgo, making it the third best-selling herbal remedy, after echinecea, the cold-fighter, and ginseng, the energy-booster.

Sales “took off” last fall, among both healthy folks and those with dementia, after the Journal of the American Medical Association published a study showing it improves mental functioning in people with dementia, says Thomas Aarts, executive editor of the Nutrition Business Journal in San Diego.

Even the government is intrigued. The National Institute on Aging and the Office of Alternative Medicine are jointly sponsoring a two-year study in 42 patients with Alzheimer’s disease at Oregon Health Sciences University.

The ginkgo tree responsible for all this is a natural wonder. It’s so ancient – its ancesters appeared 300 million years ago – it’s known as a “living fossil. And it’s so resistant to environmental toxins that it thrives in smoggy cities worldwide. And therein may lie its secrets.

The tree’s resistance to insects and toxins may stem from its chemical makeup, says Varro Tyler, a plant medicine specialist emeritus at Purdue University and co-author of “Rational Phytotherapy, a Physicians’ Guide to Herbal Medicine.”

Its two main constituents are the flavonoids, which gobble up free radicals (harmful byproducts of oxygen metabolism), and the ginkgolides, which inhibit a natural platelet activating factor and therefore make the blood less likely to form clots that can clog arteries.

Ginkgolides are devilishly complicated molecules. In fact, Harvard chemist Elias J. Corey, who won the 1990 Nobel Prize for developing a method to synthesize complex organic molecules, including ginkgolide B, recalls that he became interested in the ginkgo molecule precisely “because it was such a challenge.”

Because ginkgo seems to boost blood flow and combat free radicals, the German Commission E, a government-appointed panel that reviews herbal therapies, recommended it in 1994 for dementia-related memory deficits, dizziness, ringing in the ears.

Ginkgo may also help alleviate impotence caused by anti-depressant drugs, according to Tyler.

So far, there have been more than 100 studies on ginkgo by plant medicine scholars, including 36 German studies in the 1980s in which patients with declining intellectual function appeared to benefit from 120 to 160 milligrams a day of ginkgo extracts. German authorities later criticized these studies for not including measurements of daily functioning as well as symptoms of disease progression.

But two recent studies did include those measures. In 1996, a Berlin study of 156 patients with Alzheimer’s disease or stroke-related dementia showed that a particular ginkgo biloba extract called EGb761 was a modestly effective and safe treatment, at a relatively high dose of 240 mg a day.

Last year, in the JAMA study of 202 dementia patients that sent American sales soaring, Dr. Pierre L. Le Bars, executive research director at the New York Institute of Medical Research in Tarrytown, also found that extract modestly effective.

About 27 percent of patients responded to ginkgo, Le Bar says, about the same response rate that occurs with a prescription drug called Cognex and less than the 40 to 50 percent response rate to another prescription drug, Aricept.

Compared to a placebo or dummy drug, a relatively low dose of ginkgo (120 mg a day) is linked to slight improvements in intellectual function, social behavior, and mood, Le Bars found.

In other words, ginkgo is promising, but not dazzling.

In fact, the effects of ginkgo are “so minuscule that. . .they may mean little from a functional point of view,” adds Dr. Thomas Perls, a geriatrician at Beth Israel Deaconess Medical Center. “Ginkgo is barking up the right tree. I just don’t know if it’s the right dog.”

Still, it’s being taken ever more seriously by researchers.

Jerry Cott, head of adult psychopharmacology research at the National Institute of Mental Health, says ginkgo has been shown in test tubes to protect neurons. And data suggest, he says, that ginkgo “is potentially more effective than vitamin E,” which in high doses can slow progression of dementia symptoms.

But there’s no evidence yet that ginkgo can actually prevent Alzheimer’s, “and that’s where we really need the answer,” adds Cott, who is helping the World Health Organization design a study to find out.

Marilyn Albert, director of gerontology research at Massachusetts General Hospital, agrees: “I’d be cautious, because the government does not oversee manufacturing of ginkgo and other products sold as dietary supplements. And this drug, like any other, might potentially interact with other medications.”

Still, barring reports of horrible side effects, the appeal of ginkgo is likely to continue to grow. So if you want to try it, start with 60 to 180 mg a day in divided doses, suggests Barry Taylor, a naturopathic doctor at the New England Family Health Center in Weston who says he’s recommended ginkgo to “hundreds” of patients.

But make sure the label says the capsules contain roughly 24 percent ginkgo flavonoids (also called flavonone glycosides) and 6 percent terpene lactones (also called ginkgolides A, B and C and bilobalide, a related compound.)

Discontinue ginkgo if you get a rash or other allergy. And because ginkgo can make blood less likely to clot, don’t take it without consulting your doctor if you have a bleeding disorder or take blood-thinning drugs, including aspirin.

Arthur Borneman, a 74-year-old Quincy man, had a pain in the neck. He tried painkillers, months of therapy at a rehab hospital, massage, exercise, even a dental specialist in case the problem was jaw pain. 

To his surprise, the dentist urged him to see a chiropractor, but Borneman said he “had no faith in chiropractors.”

Still, figuring he had nothing to lose, Borneman went to Barry Freedman, a Quincy chiropractor who practices with his daughter, Gabrielle. Four weeks after his first visit, Borneman says, “I am much better. I feel like living again.”

Joan Doody, 33, a nurse from Needham who hurt her back lifting patients, offers a similar testimonial after seeing Michael Frustaci, a chiropractor in Wellesley and Brookline who quickly “adjusted” her spine and sent her happily on her way.

Despite many such stories from satisfied clients and some evidence that “back-cracking,” or spinal manipulation, is safe and effective for some types of back pain, chiropractic therapy is one of the most contentious of the alternative medicine practices now sweeping America.

There are still major grudges between chiropractors and doctors, several years after the chiropractors won a 16-year court battle to get the American Medical Association to stop trying to eliminate the chiropractic competition by refusing to refer patients or accept patients referred by chiropractors.

And there’s heated debate within the profession as well. Some, like Frustaci, think chiropractors should stick to manipulating the spine to ease sore backs and other musculo-skeletal problems. This is both “highly effective,” he says, and precisely what chiropractors learn in their specialized, four-year training.

Others, like Freedman, say that even though though they do not have M.D.degrees, most chiropractors “look at themselves as primary-care providers.They can diagnose whether the patient can benefit from chiropractic and/or whether they need a consultation from another doctor.”

And chiropractors still face criticism from many quarters, including the California-based National Council Against Health Fraud whose president, William Jarvis, a health education specialist, puts his criticism bluntly:

Chiropractic “is so bizarre, so dangerous and so bad that even when you just tell the straightforward truth about it, people think you are exaggerating.”

Even defining the basic concept of chiropractic is up for grabs — the notion that “subluxations,” or tiny misalignments of spinal vertebrae, are real phenomena that show up on X-rays, cause virtually all disease and can be forced back into aligment with a thrust of the hands.

This belief began with the founder of the movement, Daniel David Palmer, an Iowa grocer who more than 100 years ago claimed to cure a man of hearing loss by manipulating his spine. This is highly unlikely because the nerves for hearing all lie within the skull.

Furthermore, chiropractors have never been able to show that subluxations even exist, says Jarvis. No one has been able to correlate back pain with specific spinal misalignments, and many people with back pain have perfectly normal spinal X-rays, while some with abnormal X-rays have no pain.

The debate over subluxations has been so heated that, over a decade ago, chiropractor Ron Slaughter and like-minded souls founded their own group, the National Association for Chiropractic Medicine, to renounce what Slaughter calls “the historical, philosophical hypothesis that subluxation is the cause of all disease, which it surely is not.

“Subluxation is a metaphysical disease. . .and consequently, chiropractic today is practically a religion.”

Yet for all that, there’s no denying its popularity.

Last year, 22 million Americans went to a chiropractor, according to the

American Chiropractic Association, and half of all HMOs, or health maintenance organizations, now include a chiropractic benefit. In fact, despite lingering animosity, some doctors now refer patients to chiropractors, and most health insurers now cover the service, which runs about $35 a visit.

That’s partly because some research suggests spinal manipulation — a forceful thrust on the backbone — may help.

At RAND, a nonprofit think tank in Santa Monica, Calif., medical sociologist Ian Coulter and others conducted two meta-analyses in which they pooled data from various studies on manipulation for pain in the lower back and the neck.

Manipulation is defined as moving a joint to the limit of its range of motion and is often characterized by a popping sound, caused by escaping gases in the joint. Mobilization is moving the joint within its range of motion.

Although chiropractors helped fund the RAND study, the researchers focused on manipulation itself, not on who does it. In practice, chiropractors do the most spinal manipulations, but osteopaths (whose training is similar to that of M.D.s), physical therapists and others do, too.

The first RAND report, which became part of a 1994 report by the government’s Agency for Health Care Policy and Research, found positive but “not overwhelming” evidence that manipulation eases acute low back pain, says Coulter. There was was too little evidence to draw conclusions on chronic low back pain.

In a second report last year, the RAND team found that manipulation and mobilization both work for acute neck pain, though, again, the evidence on chronic pain was inconclusive. More recently, a Quebec study on whiplash and related injuries found that manipulation does seem to help with neck pain.

The RAND research also suggests that spinal manipulation is safe, says Coulter, with a “very low complication rate” — one in every one to two million adjustments.

Dr. Scott Haldeman, a chiropractor who is also a clinical neurologist at the University of California at Irvine Medical Center, concurs.

Haldeman acknowledges there is a small risk of stroke after manipulation because sudden twisting — even a quick turn of the head while driving or tipping the head back for a beauty salon shampoo — can injure arteries inside the vertebrae.

But this is “extraordinarily rare,” he says, and others note that it probably happens only to people who have a rare, hard to diagnose, anatomical abnormality. Still, Jarvis notes that over the years there have been reports of more than 100 strokes after spinal manipulation, and one recent California study, he says, found 56 strokes related to manipulation in just two years.

But Coulter says his team looked hard for examples of manipulation-related strokes and found very few.

It may also be dangerous to have any kind of manipulation too often, because ligaments along the spine may get stretched too far. And you should be wary of spinal manipulation if you have a suspected fracture, rheumatoid arthritis, severe osteoporosis, a bleeding disorder and any spinal infection or inflammation.

It’s still an open question whether chiropractic treatment, even with very gentle pressure, is appropriate for children.

Some say no, but Haldeman, whose father was a chiropractor, says he had his first adjustment “when I was a baby” and adds that he “treated my kids when they were young.”

In the end, it’s an individual decision whether to try chiropractic and if so, with whom. If you choose it, though, one rule of thumb is to steer clear of a chiropractor who says you need endless treatments.

In most cases, says Frustaci, people “don’t need more than six manipulations for any given episode of pain.” In fact, most bouts of back pain go away on their own in about four weeks.

You should also be skeptical of a chiropractor who tries to sell you vitamins, as some do, notes Haldeman.

And while Jerome McAndrews, spokesman for theAmerican Chiropractic Association, insists chiropractors “are trained in the full scope of diagnosis to the level of a general family practitioner,” others advise taking medical problems that are not obviously related to the spine to a physician.

Frustaci makes no bones about chiropractic’s limits: “My wife is a physician. There’s things I know I have no clue about, that my training doesn’t even come close to.”

You might also question a chiropractor who seems too eager to take X-rays.Although Medicare insists on X-rays to prove that “subluxation” is present, Frustaci says, this is odd, given the ongoing debate on whether subluxation even exists.

It is also a red flag if your practitioner has so much faith in chiropractic

that he or she advises you not to have your kids immunized against common childhood diseases.

As with so many other things, Jarvis says, it’s a case of “buyer beware.”

Dr. Margaret Slater, a veterinarian and epidemiologist at Texas A & M University, gives the stuff to all her loved ones, two-footed and four-footed, who suffer from arthritis.

“My dog, my horse, my mother and her dog are all benefitting from it,” she says with a chuckle.

Dr. David Hungerford, chief of orthopedics at the Good Samaritan Hospital in Baltimore, is waiting to see – and perhaps even conduct – a clinical study on the substance.

But meanwhile, this Johns Hopkins surgeon whose arthritic hands perform 300 joint replacement operations a year, many on people with arthritic knees, has begun taking the stuff himself.

“I’ve had significant improvement,” he says.

In Toronto, Dr. Joseph B. Houpt, director of rheumatology at Mt. Sinai Hospital, is already doing a study, prompted by enthusiastic reports from patients who buy the remedy in health food stores. And by watching his dog.

“I have two yellow Labs,” he says. “One was creaking and groaning, unable to jump over stumps, unable to jump up on the couch.” She’s been “like a pup” since she’s been on the drug.

Oops. We are not supposed to call this stuff a drug, no matter how much it sounds – or acts – like one. Officially, it’s a dietary supplement, actually two supplements called glucosamine and chondroitin sulfate, which are made naturally in the body and are found, in tiny quantities, in food.

The supplements have been selling briskly, thanks to high profile reports in the media and a best-selling book with a vastly over-hyped title.

Taken separately, the supplements appear safe, based on studies in Europe, and to protect against the cartilage destruction that is the hallmark of osteoarthritis, which affects 16 million Americans. Rheumatoid arthritis affects another 2 million.

Because they are sold as supplements, these products are available in health food stores, pharmacies or by mail order. They are not approved by the Food and Drug Administration which means, of course, that you don’t have the government’s assurance that the products really work and are safe.

Still, these alternative remedies are clearly setting America’s arthritic toes a-tappin’ and hands a-clappin’ – as they have in Europe for years in both oral and injectable versions. (The injectable form is not available here.)

At the Bread and Circus store in Cambridge, one combination product, Joint Fuel by Twin Laboratories, is selling “extremely well,” says acting assistant nutrition manager Catherine Devine. And another, marketed as Glucosamine Chondroitin Complex by the Solgar Vitamin and Herb Company, is sold out.

Glucosamine or chondroitin are selling well separately, too.

The only patented combination product is Cosamin, made by Nutramax Laboratories, Inc. in Baltimore, which also makes a nearly identical product, Cosequin, for animals. Like the health food products, Cosamin, which Nutramax may someday try to market as a drug, is a hot seller in pharmacies and doctors’ offices – $ 100 for a 60-day supply for a person under 200 pounds.

So far, there is not a single published study on the combination of glucosamine and chondroitin in humans, although several on Cosamin are in the works, says Dr. Todd Henderson, a veterinarian and vice president of Nutramax. Several studies of the combination product show promising results in animals.

But there are a number of European studies in people that suggest that, taken separately, glucosamine or chondroitin can help substantially. Glucosamine probably works by stimulating the cells that make cartilage, and chondroitin, by inhibiting cartilage breakdown.

Much of the fascination with these supplements has been triggered by the best-selling, if misleadingly-titled book, “The Arthritis Cure,” by Dr. Jason Theodosakis, a Tucson physician. Theodosakis says the osteoarthritis in his knees and one elbow was so bad he was on crutches and “couldn’t even brush my teeth.”

Despite surgery, he was convinced he would never live without pain and stiffness, despite high doses of anti-inflammatory drugs. But within two weeks of taking the dietary supplements, he says, he began experiencing a “dramatic recovery.”

Since then, he says he’s treated hundreds of people, though he sounds slightly chagrined at having used the word “cure” in his title, which the American College of Rheumatology calls “irresponsible” and the Arthritis Foundation, “deceptive.”

In an interview and in the book, Theodosakis is more cautious, saying he needed ” a catchy title” and that he’s talking about curing symptoms, not the disease itself.

Others studying glucosamine and chondroitin are also trying to temper the growing public enthusiasm.

Dr. David Eisenberg, a self-described “open minded skeptic” and director of the center for alternative medicine research at Beth Israel Deaconess Medical Center, is intrigued but cautious, because people with arthritis are so eager to try anything that might help. Eisenberg is considering whether to conduct a study of sea cucumbers, a Chinese remedy for arthritis.

Dr. Amal Das, an orthopedic surgeon in Hendersonville, N.C. who does knee and hip replacement surgery, is already conducting a double-blind, placebo-controlled trial of Cosamin in 100 arthritis patients.

At regular intervals, patients complete a questionnaire assessing their pain, says Das, who has previously studied other medications to help patients avoid joint replacement surgery.

In Toronto, rheumatologist Houpt is also doing a double-blind study on 100 patients, though he is testing glucosamine alone, not the combination product. He’s heard the promising anecdotes, but warns, “You have to have a balanced approach to this. That’s why it’s important to look at large populations.”

Hungerford, the Johns Hopkins surgeon, agrees, adding it is “theoretically possible” that the supplements, if taken before cartilage is destroyed, could reduce the need for some of the 200,000 knee replacements and more than 200,000 hip replacements done every year.

“But in order for me and thousands of other physicians to become convinced that this is the recognized and preferred first line of treatment, double-blind, placebo-controlled, multi-centered trials need to be done,” he says.

And unless these studies are done and the FDA gives its blessing, there’s no way to be sure that what you buy will work and be safe, or even that the labels on the bottles will tell the truth. In fact, one study of nearly 30 glucosamine or chondroitin products found that several did not contain the doses specified.

“I can’t imagine there are real big safety problems,” says Dr. David Felson, a rheumatologist at Boston Medical Center. And the FDA says it has received no complaints about either dietary supplement.

But Felson warns, “You don’t know what else might be in the stuff that you buy in the health food store.”

If you do decide to treat yourself, the dose Theodosakis suggests is 1,500 milligrams of glucosamine and 1,200 milligrams of chondroitin sulfate per day for a person who weighs between 120 and 200 pounds.

Three tablets of Cosamin provides that dosage. Each tablet also contains 66 milligrams of ascorbate and 10 milligrams of manganese to enhance absorption. But other combination products may not meet this suggested dose. Each table of Joint Fuel, for instance, contains only half as much glucosamine and only a tiny bit, 17 milligrams, of chondroitin.

If you want to try the supplements, you should definitely talk it over with your doctor, among other things, to confirm that you really do have arthritis and not some other problem.

But the bottom line, says Das of North Carolina, is that it’s “probably okay” to try the supplements, especially since “there are no known side effects.”

The risks, in other words, are all yours. But the benefits may be, too.

The Cheyenne used it for sore gums, the Comanches, for toothaches and sore throats. Other Native Americans kept it on hand for snakebites or syphilis.

Modern Americans seem to love the stuff, too, even if we can’t pronounce it. In fact, echinacea – that’s eck-in-EH-shia – is now the top selling herbal remedy in health food stores, though garlic and ginseng claim top honors in overall sales.

Unlike many medicinal herbs, this daisy-like flower, also known as purple coneflower, quite literally has its roots in America, not Asia. And compared to many plant medicines, there’s a fair amount of research on it – 350 studies by some counts.

Some people swallow the nasty-tasting liquid form of echinacea or sip it as tea at the first sign of a cold or flu. Others use it as a salve on burns or wounds that won’t heal. Others gargle it for strep throats or take it, internally and externally, for herpes. Some even give it, in small doses, to their kids.

But at $ 10 to $ 20 a bottle for the liquid stuff – depending on how much you use, a bottle may last three weeks – should we?

The answer, say many pharmacognocists, or scholars of medicinal herbs, is a hearty “why not?” It appears safe for many people and may, as advertised, stimulate the immune system. If you’re allergic to ragweed, though, or have HIV/AIDS or an autoimmune disease like lupus or multiple sclerosis, you should probably give it a miss.

While some of the research on echinacea may still not meet rigorous scientific standards, researchers in Germany – where doctors prescribed echinacea 2.5 million times in 1994 alone – have come up with provocative findings in recent years.

In one double-blind, placebo-controlled study of 180 volunteers, a German team found in 1992 that high doses of an alcohol-based extract of Echinacea purpurea root seemed to reduce the severity and duration of cold and flu symptoms.

But the dose appeared to be crucial. People who took 900 milligrams (or 180 drops) a day showed significant improvement. Those who took half that were no better off than people given a placebo, or dummy drug.

In another 1992 double-blind, placebo-controlled study of 108 people with chronic upper respiratory infections, those given 4 milliters of E. purpurea in liquid form twice a day for eight weeks had fewer infections than those taking a placebo.

In 1994, another German researcher reviewed 26 controlled human studies. Together, he concluded, the studies suggest that echinacea can stimulate the immune system.

But caveats are in order. The studies involved three types of echinacea, as well as combinations of types, and the quality of some studies was low, warns Steven Foster, an Arkansas plant photographer who writes on herbal research for the American Botanical Council, a research and educational group.

While echinacea does not kill bacteria, research suggests it does increase the number of white blood cells, as well as the process of phagocytosis, or the gobbling up of invading organisms by immune cells. It may also block an enzyme that helps infections spread.

There’s some evidence that echinacea also stimulates cells called fibroblasts, which play a role in healing wounds, says Cathy Crandall, a researcher of medicinal plants at Washington University in St. Louis.

The problem, though, says Dr. Jerome Groopman, an immunologist and chief of experimental medicine at Beth Israel Deaconess Medical Center, is that “you’re kind of poking in a black box.”

Lots of natural products stimulate some parts of the immune system, he says, but what’s needed is a “rigorous evalution” of echinacea and other herbs.

Still, those who do study herbs seriously, among them Gail Mahady, a pharmacognocist at the University of Illinois in Chicago, say the data on echinacea are a lot more solid than that on some herbal remedies.

“I don’t think anyone could look through the literature and honestly say echinacea doesn’t stimulate the immune system,” she says.

Echinacea “is one of the few herbs I take,” adds Varro Tyler, who has studied dozens of herbs and is professor of pharmacognosy emeritus at Purdue University.

So far, no one is sure which of echinacea’s constituents might account for such effects, though there’s some evidence that one component, high molecular weight polysaccharides, can activate cells that gobble up invading germs.

A more pressing question, for most consumers, is which kind of echinacea – E. angustifolia, E. pallida or E. purpurea – to take, and in what formulation.

Most of the research has been done on E. purpurea, and it is this type of echinacea that the German Commission E, the leading authority on herbal remedies, recommends for colds and respiratory infections and for urinary tract infections as well.

The Germans endorse the above-ground parts of E. purpurea – not the roots – taken either as pressed juice in an alcohol solution or as an injection. (Injections of echinacea are not available in this country, though they are in Germany.)

There has been less study of E. angustifolia, notes Tyler, though he thinks the roots of this form may actually be the best product. In practice, many of the dozens of echinacea products sold in America are combinations of all three types.

If you do take a combination product, says Mahady of Chicago, try to get one that contains the above-ground parts of E. purpurea and the roots of E. angustifolia and E. pallida. Some products give this information on the label.

Mahady takes the stuff herself – the 22 percent liquid formulation, not the capsules – whenever she feels a cold coming on. “It tastes terrible,” she says, but seems to help.

And if you take echinacea, the German Commission suggests, stop before eight weeks because it loses effectiveness over time.

Dr. Carol Englender, a Newton physician who also uses herbal remedies, says she recommends echinacea often. “Just today, I told four people to take it for the rest of the winter,” she said recently. “It’s good stuff.”

And while some think echinacea in an alcohol solution works best, Englender believes the capsules are effective, too.

Dr. Edward Chapman, another Newton physician who recommends echinacea to patients, adds that “the nice thing is it’s safe, and you can use if for kids.”

For adults, he says, the usual recommendation is 90 drops a day – you quickly learn how to gauge how many drops are in a dropperful – spread over three doses. Manufacturers – backed by German research – often recommend as much as 150 drops a day. For small children, Chapman says, 10 drops a day often help, and for kids between 5 and 10 years of age, 20 drops.

But the bottom line, says Arkansas herbalist Foster, is that when it comes to choosing the best dose and a formulation, “what we don’t know is greater than what we do know.”

Fuzzy thinking about herbs

Despite the booming popularity of herbal remedies among consumers, a number of myths remain, perhaps the silliest of which is the idea that anything “natural” must be safe and anything synthetic, dangerous.

But mushy thinking among fans of herbal medicine often goes further than that, verging on what Varro Tyler, an herb scholar and professor of pharmacognosy emeritus at Purdue University, calls “paraherbalism,” a belief in the superiority of anything natural and organic.

Other tenets of paraherbalism, which Tyler discusses in his 1994 book, “Herbs of Choice,” include these beliefs:

• There is a conspiracy by the medical establishment to discourage the use of herbs. Wrong, says Tyler. It’s just that doctors know little about herbs because medical schools don’t teach them and pharmaceutical firms don’t bother studying herbs because they see no profit in doing so.

• Herbs cannot harm, only cure. Wrong again. Some highly toxic substances, including the amatoxins, strychnine, ricin and many others are derived from plants.

• Whole herbs are more effective than their components. For every example that supports this, says Tyler, there’s another that contradicts it, because many herbs also contain toxins.

• Reducing the dose of a medicine increases its efficacy.  This is a central tenet of homeopathy, an enterprise philosopically different from herbal medicine. Many scientists, Tyler among them, think homeopathy makes no sense.

• Herbs were created by God specifically to cure disease. “This thesis,” as Tyler puts it, “is not testable and should not be used as a substitute for scientific evidence.”