SOMEWHERE IN THE DARK, FAR from prying eyes, the kombucha waits, gathering strength while it grows, duplicating itself, waiting. And when its moment comes, when a human invokes its fabled powers, it is ready...ready to clear up pimples, cure tired blood and put waning sex drives into overdrive.

Tea made from the kombucha mushroom, as it's called—although technically it's not a mushroom but a combination of yeast, bacteria and lichen—is the panacea du jour among alternative medicine's true believers. Although the Federal Drug Administration hasn't ruled on its brew's virtues and mainstream medical experts urge caution, kombucha's proponents, who claim it is a 2,000-year-old folk medicine that originated in Manchuria, or maybe Egypt, have no doubt where they stand.

Betsy Pryor, who has shipped 4,000 fungi from her Los Angeles-based Laurel Farms company, says, "This has reached out and touched people's hearts. Buddhist monks, sisters and priests, even Orthodox rabbis—they're all drinking it." She found out about kombucha in August of 1993, after a meditation session at her guru's ashram in West Hollywood. "I'd been asking God that since the planet was so sick, wasn't there something out there I could do to help heal people," she says. A fellow believer invited Pryor to quaff a tealike drink with a "gelatinous thing" sitting in it. "Within a few days," says Pryor, "my energy started to lift, and my skin started to clear up."

Pryor had found her mission: selling $50 kombucha home-brew starter kits—plastic bags containing a lily pad-shaped kombucha and some tea. After about 10 days, in which the kombucha ferments in water, with sugar and tea added, the vinegar-tasting beverage—also available from health food stores—is ready for sipping. Devotees advocate drinking four ounces of kombucha three times a day. As yet there have been no reports of unwanted side effects, except for a syndrome that initiates call the kombucha retch factor, caused by drinking too much of it. So far there's no cure for that.