Not all grass is for hay. And that popular ”grass”, marijuana, is definitely not on the Generally Recognized As Safe (GRAS) list. Indeed, most of the psychoactive herbs carry significant risks, sometimes with single-use and often with repeated use. There is adequate scientific literature to provide a list of herbs which have produced medical and health problems.

I had not expected Maca to make that list. However, I now have seen two individuals, who had always had low normal blood pressure, develop significant hypertension while taking Maca. In both cases blood pressure returned to normal when the Maca was discontinued. Ordinarily, Maca may be helpful in treating menopause and andropause. Almost all foods can cause mild to serious allergies or unusual hypersensitivy reactions. So can herbs, even some ordinarily considered therapeutic.

The following herbs have been reported to have potentially negative or adverse effects:

Stimulants or euphoriants:

  • California poppy
  • Cinnamon
  • Damiana
  • Hydrangea
  • Gota kola
  • Mate
  • Mormon tea
  • Passion flower
  • Tobacco
  • Lobelia.


  • Yohimbe
  • Catnip
  • Juniper
  • Kava kava
  • Mandrake
  • Marijuana
  • Nutmeg
  • Periwinkle
  • Salvia divinorium
  • Snake root
  • Thorn apple
  • Wormwood


  • Prickly poppy
  • Wild lettuce.


  • Scotch broom
  • Valerian

Kava kava has also produced liver damage. Ginseng may cause painful, swollen breasts. Mistletoe is toxic. Polk plants and berries are toxic. Seeds or pits and even bark of apricot, bitter almond, cherry, peach, pear, apple and plum all contain cyanide compounds.

Sassafras can cause ataxia, severe hypersensitivity, depression, liver damage and even death. Devil’s claw, St. John’s Wort, and pennyroyal can cause miscarriage and pennyroyal can lead to kidney and liver failure.

Large dosages of mate can cause liver failure. Lead, mercury and arsenic intoxication have been reported from use of both ayurvedic and Chinese herbs. Ma Huang is ephedra and has led to hypertension and death. Oleander has toxic effects on the heart. Uva ursi has caused acute macular degeneration.

Undoubtedly, pharmaceutical drugs harm and kill many times more individuals than do herbs. And many herbs are wonderfully healing. Ginger, tumeric, frankincense, saw palmetto, mint, Echinacea, ginkgo biloba, polygonum multiflora, tribulus, nettles, most culinary herbs/spices, and the marvelous combination found in Little Swedish Bitters are all favorites of mine.

C. Norman Shealy, M.D., Ph.D. is the father of holistic medicine. He recommends autogenic focus (the basis of the Biogenics System) as part of your commitment to self-health. Register to download your FREE autogenic focus MP3 now.

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