Safety When You Use Herbs.

Plants have the power to heal…but first, know these basics for safe and effective results.

Humans, like most mammals, have turned to plants for food and medicine since our earliest times. No doubt some of our ancestors suffered the consequences of unfortunate choices along the way.

Most of the herbs sold in the United States are safe when taken in recommended dosage. More than 38 million Americans use herbs each year, yet the majority of calls to Poison Control Centers about plant ingestion have to do with people {usually children} and pets eating the potentially poisonous house and garden plants, not medicinal herbs.

To ensure your experiences with medicinal herbs remain positive without inadvertent mishaps-follow these basic guidelines.


Start with Food Herbs

You can bet on safety when you use herbs as foods-think garlic, ginger, nettles, dandelion greens, shitake mushrooms, burdock root {also called gobo} and rose hips. Culinary herbs-thyme, oregano, turmeric, cayenne are also low-risk. Externally applied herbs {compresses, poultices, salves} provide another good testing ground.

The next step is to begin experimenting with infusions {commonly known as “teas”}. Many of the food herbs mentioned above can be dried, chopped, and steeped as tea. Extracts of herbs in alcohol {tinctures} or glycerin {glycerites} generally are more potent. Solid extracts, in which all the solvent has been removed, and carbon dioxide extract herbs are stronger still. Standardized extracts are designed to have a consistent level of suspected active ingredients from batch to batch. This process allows for more precise dosing and easier use in research, but also makes the product closer to a drug.

Allergy-Prone? Proceed with Caution

Simon Mills, an internationally known herbal authority and coauthor of The Essential Guide to Herbal Safety {Elsevier, 2005}, says, “Allergic reactions are the most common type of herbal side effects although still infrequent.” Sensitive people who handle plants or apply them to their skin could develop contact dermatitis {an itchy skin rash}, and inhaling the herbs could aggravate hay fever or asthma. Allergic responses to ingested herbs include skin rash, stomach upset and, at the extreme, life-threatening anaphylaxis.

If you’re allergic to ragweed, you might react to other members of the aster family, such as chamomile, echinacea, and feverfew. More rarely, people can have allergic reactions to cayenne, kava {a member of the pepper family}, garlic, and mints.

“If you are prone to allergic reactions, be careful with your herbal attempts,” Mill says. Try one new herb at a time. Start with half the recommended dose, then gradually increase to the full recommended amount. If you develop a rash, upset stomach, itchy eyes or sneezing, stop taking the herb. If your lips or throat begin to swell, seek emergency care.

Investigate Herb-Drug Interactions

If you are taking both herbs and pharmaceutical drugs, you’ll want to avoid two possible scenarios: 1 interfering with the drug’s effects, and 2} amplifying the drug’s effects.

A herb can interfere with a drug’s effects it acts in the opposite way, for instance, drinking three cups of stimulating black tea or coffee after taking a sedative Valium. A herb also might lower blood levels of a medication, thus thwarting its intended action. St. John’s wort is famous for doing just that. By speeding liver enzyme systems that break down drugs, it reduces blood levels of a long list of medications, including some antihistamines, chemotherapeutic and anti-HIV drugs, warfarin, and oral contraceptives.

Furthermore, St. John’s wort, which has a good track record as an antidepressant, shouldn’t be combined with pharmaceutical antidepressants because it can raise blood levels of the chemical serotonin to dangerously high levels.

Combining herbs with drugs that have similar actions can increase the drug’s desired effects or its unpleasant side effects, and the net effect could be good or bad. For instance, some Chinese studies have found astragalus {Astragalus membranaceus} augments some anti-cancer drugs and decreases the drug’s side effects. {Note: Researchers used injectable forms of the herb.}

In other cases, too much of a good thing can be bad. Taking anticoagulant {“blood-thinner”} drugs {aspirin, warfarin, heparin} with therapeutic doses of anticoagulant herbs {garlic, ginkgo, ginseng, and others}, for example, can result in bleeding. It’s also wise to discontinue the use of such herbs seven to 10 days before surgery.

As a general rule, avoid mixing herbs and drugs with the same actions so you do not become overly stimulated, sedated, anticoagulated, etc.

Know When to See Your Health-Care Provider

Sick infants should be seen immediately by a practitioner with pediatric training. Also, seek the help of your health-care provider if you know, or suspect, you or another adult has a serious condition. Self-medication with herbs runs the risk of delaying or interfering with medical treatment, potentially with  disastrous consequences. Even if you have a mundane illness, make a doctor’s appointment if three days of home care haven’t alleviated your symptoms. Please work in partnership with your physician.

Also, be sure to tell your physician about any herbs you are taking prior to scheduling surgery. Some herbs, especially those with anticoagulant action, should be discontinued seven to 10 days before surgery, or as your doctor advises.

Use Extra Caution When Giving Herbs to Children

Babies younger than 6 months {or around the time a child begins eating solid food} should not take herbs internally. Small amounts of gentle herbs can be applied to an infant’s skin via salves, oils, baths and compresses {a cloth dipped in herb tea}.

For older children, dosages usually are calculated by weight. Take the child’s weight in pounds, divide it by 150 {an average adult weight} and multiply that number by the adult dose. For instance, if an adult dose is 100 mg and the child weighs 50 pounds, the child’s dose would be 30 mg {50/150 x 100 = 0.3 x 100 = 30 mg}.

Children aren’t simply small adults, however. Some herbs generally regarded safe for adults should not be given to children. To find out more, ask an herbal expert or get a book, such as Naturally Healthy Babies & Children by Aviva Romm {Storey Publishing, 2000}.

Use Gentle Herbs when Pregnant or Nursing

Many plant constituents pass from the intestinal tract into the blood, across the placenta to the fetus’ blood and, later, into breast milk.

If you’re pregnant, you generally should avoid putting anything medicinal into your body, Avoid consuming herbs with laxative effects {senna, cascara sagrada, aloe}; hormonal properties {licorice, black cohosh, dong Quai, chaste tree, sage, red clover}; or stimulant effects {guarana, kola, yerba mate, tea, coffee}.

Food herbs usually are safe bets, particularly when used in quantities suitable for flavoring. While no obstetrician will tell you to cease cooking with garlic and oregano, some culinary herbs, such as sage and parsley, might not be recommended in higher therapeutic doses. Most experts agree pregnant woman can take these herbs safely: ginger {no more than 1 gram a day to reduce nausea}, raspberry leaf, echinacea, chamomile, bilberry {fruit, not leaf}, cranberry, hawthorn, hibiscus flowers, rose hips, mullein, spearmint, and nettles.

Be Wary of Imported Herbs

Some herbal products from Asia, India, and the Middle East reportedly have been adulterated with undesirable plants and/or contaminated with heavy metals, sulfates, pesticides and other toxins. In Chinese herbal formulas, herbs can be blended with pharmaceutical drugs not mentioned on the label. Also, Aristolochia fang chi, which has been substituted for other herbs, has been linked to severe kidney damage. Rather than give up on Asian herbs, “I personally would stick to whole herbs I can see, then make my own formulation,” says Mills.

Use Essential Oils Wisely

Essential oils are extremely concentrated. Herbalist and aromatherapist Diana Jones gives the following rules for using them safely:

1} Don’t apply essential oils to any mucous membrane: mouth, ears, nose, eyes, vagina or rectum.

2} Don’t take essential oils by mouth and keep the bottles out of the reach of small children.

3} Don’t apply undiluted essential oils to the skin. The standard dilution is 10 to 12 drops of essential oil per one ounce of carrier oil {such as almond or jojoba}. Use half that amount or less for people who are debilitated; those with sensitive skin; and for children 5 to 12 years old. Don’t use essential oils for children younger than 5.

4} Be cautious when inhaling or applying essential oils to the chest if you are prone to asthma.

Educate Yourself

Anyone interested in herbal medicine should have a good reference book on herb safety.


The Essential Guide to Herb Safety by Simon Mills and Kerry Bone {Elsevier, 2005}

Herb Contraindications and Drug Interactions by Francis Brinker, N.D. {Eclectic, 2001}

Botanical Safety Handbook by Michael McGuffin, et al {CRC, 1997}

The ABC Clinical Guide to Herbs by Mark Blumenthal, et al {Thieme, 2003}