(FORTUNE Magazine) – Mary Lou Wilson, 57, used to be fat, sick, and tired -- all the time. Since she began treating herself with herbs a couple of years ago, she says she has lost 83 pounds, works 16 hours a day -- and saves her insurance company roughly $15,000 per year in reduced medical bills, mostly due to fewer hospital visits. Another payoff: A few months ago she gave husband Bob, 70, a product called PerForm, a combination of herbs with aphrodisiac properties. It worked so well, she reports, that ''after a few weeks, I said, 'This hopping into bed every day is too much.' '' So she cut back Bob's dosage. Now, says Bob, a retired American Airlines pilot, they don't have sex ''much more than three or four times a week.'' Sound like quackery? Maybe. But more and more people are turning to unconventional therapies such as acupuncture, chiropractic, and homeopathic and herbal medicine. The New England Journal of Medicine estimated that Americans made 425 million visits to alternative medicine providers in 1990, compared with 388 million visits to traditional primary-care physicians. Holistic healers collected $13.7 billion for their services that year. Among the business beneficiaries: Ken Brailsford, a former Mormon missionary who owns Enrich International, an herbal products distributor in Lindon, Utah. Brailsford won't disclose profits, but he says sales rose from $120,000 in 1985 to $30 million in 1992. Brailsford's sales organization includes 50,000 sales reps, among them Mary Lou Wilson. She sells up to $24,000 a month of nutritional products. Evidence that alternative medicine works is mostly anecdotal. So the National Institutes of Health has opened an Office of Alternative Medicine to explore its merits.