The hole in Christopher Grell's life never seems to shrink, so he fills it with activity: lawsuit filings, medical research, taking care of his son. Anything to fill the space that opened on the night his wife, June, died in her sleep in the summer of 1991. That evening the Grells had dinner. June drank her habitual cup of diet herbal tea, went to bed and expired.

She was 37 and in excellent health. Except for the curious fact that she was dead. The coroner's certificate read: "apparent natural" causes.

Michael Humphrey is a computer scientist who prefers the quiet certitude of mathematics to the chaos of human society. Chaos is what happens when your 24-year-old daughter legally buys an organically grown herb at the health food store in an attempt to induce an abortion. Chaos is what sets in when she perishes in slow agony, surrounded by doctors who are powerless to help her.

Christopher Grell and Michael Humphrey have never met, but they have a great deal in common. Both are thoughtful men, cautious men. Both have embarked on the painful public ordeal of suing the herbal drug companies that they claim caused the deaths of their loved ones. Both say they are primarily motivated by their desire to prevent other deaths in a largely unregulated industry.

Grell is suing Laci Le Beau Corp., a Fresno, Calif.-based manufacturer of Super Diete r's Tea, which June Grell drank daily for four to six months before her death. The tea is composed of locust plant, wymote, ginseng, honeysuckle and a few other plants, with the active ingredient being the locust leaf's senna, a substance common to many federally approved man-made laxatives. Naturally grown senna, however, is not subject to federal testing or approval.

Grell, a San Francisco lawyer, has alleged that his wife and three other women -- in Florida, Arizona and Minnesota -- died because the product gradually robbed their bodies of potassium and other vital electrolytes, leading to sudden cardiac arrhythmias. June Grell's death is an official medical mystery, but 22-year-old Debbie Helphrey, who dropped dead while talking on the phone in Fort Lauderdale, Fla., in 1991, was found by her treating physicians and the medical examiner to have "electrolyte derangements due to consumption of the herbal laxative tea, which induced the fatal cardiac arrhythmia," according to the toxicology report. Grell is representing the families of all four women in the lawsuit.

The chairman of Laci Le Beau Corp., Fred Stine, states that the tea contains nothing harmful, did not cause any of these deaths and complies with all relevant labeling and manufacturing laws.

An inquiry last June into herbal dietary teas by the Food and Drug Administration's Food Advisory Committee concluded that long-term use can cause loss of bowel function and fainting. The committee recommended that the products carry warning labels. To date, however, the agency has not adopted a labeling recommendation.

Kris Humphrey's case is more complex, though no less dramatic. Humphrey was a few months short of graduation from San Jose State University in July 1994 when she learned she was pregnant. She was a devoted user of herbal products for minor ailments and, according to depositions, she told her friends she was going to try to induce a "natural" abortion. She chose a substance used as far back as ancient Greece and publicized most recently by the band Nirvana: pennyroyal.

She bought pennyroyal extract and another herb, black cohosh, at a local health food store. The active ingredient in pennyroyal is pulegone, a substance known to cause gastrointestinal bleeding, destroy liver cells and inhibit clotting. Kris Humphrey most probably followed the recipe for abortion in a popular herbal guide for women: 20 drops every four hours for five days. But she did not know she had an ectopic, or tubal, pregnancy, meaning the fertilized egg was lodged in one of her fallopian tubes instead of in her uterus. She took persistent abdominal pain as a sign that the abortion was underway, her friends said. Instead, hospital records show, she was bleeding internally.

One Friday night she began vomiting continually, then had a seizure and lost consciousness. Paramedics revived her and rushed her to the hospital, where, according to hospital records, doctors discovered the bleeding ectopic pregnancy but could not fathom -- or stop -- the uncontrolled bleeding elsewhere -- from her nose, her ears, her labia. None of the doctors had heard of pennyroyal when Humphrey's friends presented them with the bottle, her father said; they called poison control and consulted textbooks to learn that it has no antidote.

When doctors finally operated Sunday to remove the embryo, Humphrey was in dire condition: She was in shock, and records show her body could not retain any of the fluids doctors pumped in. She showed little brain activity; her pupils were fixed and dilated. A neurosurgeon declared Humphrey brain-dead, and her parents decided to withdraw life support.

Humphrey's parents, who are divorced, are jointly suing Gaia Herbs, a Massachusetts-based company that makes pennyroyal extract, and Bread of Life, the health food store where Kris Humphrey allegedly bought it, for negligence, product liability and wrongful death. They are demanding unspecified damages and the addition of warning labels to the product.

Lawyers for Gaia Herbs and Bread of Life state that the pennyroyal extract the company produces is far too weak to be dangerous. If the case comes to trial, they say, they will call experts to testify that Humphrey died of shock from the bleeding ectopic pregnancy.

It is a sign of these deregulatory times that as herbal products have ballooned into a $1.5 billion a year industry, federal supervision over their manufacture has been significantly weakened. With the passage of the Dietary Supplement Health and Education Act in October 1994, manufacturers were permitted to offer some health claims on their products without fulfilling FDA drug testing requirements.

The act, sponsored by Sen. Orrin G. Hatch (R-Utah) and Rep. Bill Richardson (D-N.M.), classified herbal products as food supplements rather than drugs. This was a compromise reached after a battle in Congress between federal health authorities, who wanted tougher safety and efficacy standards, and herbal companies, who complained that they could not afford the sort of clinical testing required by the FDA for synthetic drugs. Drug companies typically spend upward of $100 million testing a prescription drug for federal approval and $50 million on tests for an over-the-counter drug, but they recoup their investments by patenting the products. Herbs alone, however, cannot be patented.

The act meant that herbal products would be essentially unregulated; the FDA still can require a warning on a product or remove it from the market, but first must prove it unsafe. That's the reverse of the procedure with drugs, where the manufacturer is required to prove a medication safe before it goes on sale. Herbal companies are thus free to market organically grown drugs that -- if man-made -- would be subject to government approval.

"Most consumers believe that there is nothing in health food stores that could kill them," said Bruce Silverglade, director of legal affairs for the Center for Science in the Public Interest in Washington. "Sadly, that is not the case."

Stephen Barrett, a medical editor and consumer advocate, said, "A consumer who intends to inform himself on what to buy in a health food store has already lost the game." He said that much of the literature informing consumers about herbal products is put out by the companies that manufacture them. "There is no way in hell anyone can sort out fact from fiction."

Varro Tyler, a Purdue University professor and author of a widely respected herbal encyclopedia, said the FDA has abdicated its role as a consumer watchdog in this area. "The FDA does nothing to prevent toxic materials from being sold," he said. "Canada took comfrey root off the market. Most civilized nations don't allow it to be sold. Here, where we're supposedly so far advanced, you can buy it anywhere." Comfrey root, promoted as a "wound-healing agent" but linked to liver damage, is not the only toxic or otherwise dangerous herb sold without restriction, though the majority of herbal products are quite mild. {See box.}

"The responsibility for safety starts with the industry," said Mitch Zeller, the FDA's deputy associate commissioner for policy. "The FDA's job is to give the best possible assurance to the public that a product is safe and properly labeled. But when it comes to safety, it is sometimes the case that we don't hear about the problems until after they occur." The agency is investigating the death of Peter Schlendorf, a college student from Long Island who died this month after taking an herbal stimulant marketed as Ultimate Xphoria and containing the Chinese herb ma huang. He bought it in a health food store.

The FDA said it can respond only to the most urgent and numerous complaints, such as, in the late 1980s, with L-tryptophan, an essential amino acid found naturally in the diet. People took tryptophan supplements, in pill form, to improve general well-being and induce sleep. Contaminants in the supplements proved to cause blood and muscle disease and caused dozens of deaths; the supplements were finally banned.

Zeller had not heard of pennyroyal, which is not surprising. Kris Humphrey is the only recorded case allegedly involving death from using the herb's extract; there is one recorded case of a death from the more potent pennyroyal oil in 1978.

Until about a year ago, there was no central registry for deaths and injuries caused by the ingestion of herbs. Now, Zeller said, there is one in the FDA's Office of Special Nutritionals. Consumer advocates such as Stephen Barrett believe that even with a registry, many incidents go unreported because doctors may not recognize symptoms tied to herbal remedies -- or from a combination of herbs and prescription drugs -- and often don't think to ask their patients whether they use herbs.

Some efforts are underway to clarify the status of herbal products. The FDA and the herbal industry are now cooperating to standardize potency levels, which may vary widely from plant to plant. The FDA has published warnings about some potentially toxic herbs, albeit in little-read newsletters, and the American Botanical Council has started a research project to evaluate other countries' systems of drug approval and to try to devise a better system of evaluation.

But none of that goes very far toward protecting consumers who use herbal products today. And with virtually no testing ongoing in the United States, there is little prospect of providing consumers with precise information. For the moment, users must fend for themselves.

In 1994, Kurt Cobain introduced pennyroyal to a generation of fans with a song called "Pennyroyal Tea" on Nirvana's "MTV Unplugged" album, which sold more than 3 million copies.

"Sit and drink pennyroyal tea," he wailed. "Distill the life that's inside of me."

According to herbal experts, pennyroyal has been used for centuries to flavor foods (it tastes minty), as a flea repellent for pets (though overuse can kill the cat along with the fleas), as a perfume, to treat flatulence and headaches, and to induce abortions. Pennyroyal was cited by the Greek dramatist Aristophanes in the 5th century B.C. as an abortifacient, and is listed as the main ingredient in a recipe to induce menstruation (another way of describing abortion) in a 1986 book called "Wise Woman Herbal for the Childbearing Year."

But it can be dangerous. "While pennyroyal oil may indeed induce abortion, it does so only in lethal or near-lethal doses," writes Purdue professor Tyler in "The Honest Herbal." "The herb has nothing to recommend it."

Tyler agrees with lawyers for Gaia Herbs that pennyroyal extract would not normally be strong enough to be dangerous. Pulegone, the lawyers say, is 6,000 times as potent in the oil as in the extract used by Humphrey.

"The stuff my client puts out is consumable if taken as directed on the label," said defense attorney Bob Luft. "We feel there is no relationship between this young lady's death and her taking the pennyroyal herbal product."

Nonetheless, the company has stopped distributing the product until more is known about its medical effects; pennyroyal oil, which it doesn't manufacture, is still widely available. Gaia Herbs is considering adding a warning label against use when pregnant, Luft said, but he quickly added that such notice has nothing to do with the lawsuit. Humphrey would not have been deterred by a warning, he said, since she took the product with the intention of ending a pregnancy.

Allen Fleishman, the Humphreys' attorney, said he intends to prove that Kris Humphrey died from the pennyroyal. Sidney Nelson, a University of Washington chemist who has been conducting pennyroyal tests for 17 years, studied a sample of Humphrey's liver, and said he found the damage to be consistent with pennyroyal poisoning. Reema Jalali, the emergency room doctor who treated Humphrey, told a local paper: "She really didn't stand much of a chance. . . . She had an ectopic pregnancy, and she had an additional insult to the liver from the pennyroyal."

In the Grell case, Laci Le Beau lawyer Mike Ryan said he would not comment before the trial, scheduled for mid-April. But in a fax from its headquarters, the company noted that the medical examiner could determine no link between June Grell's death and the tea, and said that "Mrs. Grell, in fact, had a long history of health problems," including fainting spells.

Chris Grell, however, insists that his wife had no significant health problems. He acknowledges that she had had some rare dizzy spells in the past but fainted only once, about a month before she died, which he believes also was related to the tea. "You can read the medical examiner's report; there was no pathological explanation for her death," he said. "They found nothing."

June Grell left behind a 2-year-old son, R.C. (Robert Christopher), who is now 6 and doesn't remember his mother, though with his blond hair and bright smile he resembles her a great deal. Chris Grell does the best he can to keep her memory alive, without dwelling on the painful details.

"I got frustrated with the medical examiner," Grell said. "I found it very difficult to accept that it was a natural death. I did the research to find answers, and I kind of kept hoping someone would tell me I was wrong. But every time I would get another letter back, I would realize that I wasn't off the mark."

Grell's anger has subsided into a dull throbbing, set to the pace of the endless letters, depositions and court filings related to the lawsuit. He finds it easier to relate to his personal tragedy through bureaucracy. In this regard he is a kindred spirit to Michael Humphrey, who has locked away his pain over his daughter's death, confronting the loss through meticulous research in medical libraries.

"Even if we lose this thing," Humphrey said, "if there are improvements in the labeling that can help save lives -- or, even better, if we can change the way the FDA looks at these things -- no matter what happens, that's the one thing I hope occurs."

Grell, a few miles away, echoed the thought. "Money won't buy R.C. a mother; that's not the issue," he said. "But something needs to be done to make other people aware. It will be enough when they start putting warnings on these products so people know." HERBS IN QUESTION SUBSTANCE Artemisia (wormwood) MEDICINAL USE (benefits unproven) Deworming agent, hallucinogen HEALTH RISK Has caused brain damage and death in animal studies, linked to death and brain damage in humans REGULATORY STATUS No restrictions SUBSTANCE Belladonna MEDICINAL USE (benefits unproven) Stimulant, hallucinogen HEALTH RISK Causes rapid heartbeat, has caused death in high doses REGULATORY STATUS No restrictions SUBSTANCE Black Cohosh and Blue Cohosh MEDICINAL USE (benefits unproven) Induce labor, abortifacients HEALTH RISK Have caused birth defects in lab animals and livestock REGULATORY STATUS No restrictions SUBSTANCE Chaparral MEDICINAL USE (benefits unproven) "Cancer remedy," "blood purifier" HEALTH RISK Has caused liver damage in humans REGULATORY STATUS FDA issued warning in December 1992 SUBSTANCE Coltsfoot MEDICINAL USE (benefits unproven) Cough and cold expectorant HEALTH RISK Has caused liver cancer in lab animals with extended use REGULATORY STATUS No restrictions SUBSTANCE Comfrey root MEDICINAL USE (benefits unproven) Wound-healing agent HEALTH RISK Have caused liver and bladder cancer in laboratory animals REGULATORY STATUS Banned in Canada and most of Europe, no restrictions in U.S. SUBSTANCE Kombucha tea (made from mushroom-based cultures) MEDICINAL USE (benefits unproven) "Cure-all," taken for cancer, AIDS, wrinkles HEALTH RISK Linked to two deaths by acidosis in Iowa in 1995 REGULATORY STATUS Centers for Disease Control issued warning in January 1996 SUBSTANCE Lobelia MEDICINAL USE (benefits unproven) Bronchial dilation for asthmatics HEALTH RISK Linked to paralysis of respiratory system in large doses REGULATORY STATUS No restrictions SUBSTANCE Ma Huang (ephedra) MEDICINAL USE (benefits unproven) Appetite depressant, bronchial dilator for asthmatics, central nervous stimulant HEALTH RISK Linked to circulatory problems and 15 deaths REGULATORY STATUS FDA considering warning labels recommended by October 1995 panel SUBSTANCE Pennyroyal MEDICINAL USE (benefits unproven) Animal flea repellant, abortifacient HEALTH RISK Oil causes liver damage, bleeding and inhibits clotting; caused one death in 1978 REGULATORY STATUS Banned in Canada, no restrictions in U.S. SUBSTANCE Sassafras MEDICINAL USE (benefits unproven) "Spring tonic" HEALTH RISK Has caused cancer in lab animals REGULATORY STATUS Banned for use in food and drugs by FDA, still widely available as herb SUBSTANCE Senna MEDICINAL USE (benefits unproven) Laxative, promotes weight loss HEALTH RISK Prolonged use can cause loss of bowel function, fainting, has been linked to deaths by arrhythmia REGULATORY STATUS No restrictions SUBSTANCE Yohimbe MEDICINAL USE (benefits unproven) Aphrodisiac, muscle-builder HEALTH RISK Linked to psychotic episodes, fainting REGULATORY STATUS No restrictions Sources: FDA, The Lawrence Review of Natural Products, The Honest Herbal CAPTION: June Grell, seen in a family photo taken just before she died mysteriously five years ago. CAPTION: A selection of herbal treatments available without a doctor's prescription. CAPTION: Kris Humphrey, who told friends she was going to induce a "natural" abortion, died after herb use.