Health Risks

Herbs that can cause Health Problems

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We all want to be healthy, enjoy this life that we’ve been given, for ourselves, our children and future generations.  Often trying extra hard to be healthy, has its hazards, especially when you are taking medications or even using alternatives like herbs and herbal preparations. 

There are a number of herbs that you can be sensitive or allergic to, as well as, those that can interfere with medications that you may be taking and various medical conditions whether diagnosed or undiagnosed.

You should never be afraid to try an alternative or natural cure because most of these, like our bodies, are of nature and can be very beneficial for health maintenance, but before using any herb as medicine, you should be responsible and consult your physician or a good holistic health practitioner, integrative physician or herbalist, for safety reasons.  Make sure that you have the correct diagnosis; get a second and third opinion if you have to.  Used properly and in the right amounts, most herbs can be great medicine.

It’s also important to know that many culinary herbs can also be harmful if you have certain health conditions, such as allergies, seizures, etc., or if you are taking medication for any reason, combining them with some medications can even kill you.

Culinary herbs, such as Rosemary and Sage can actually make seizures worse, bring on an episode or cause them.  Especially when combined with some OTC medications that cause seizures, such as Tylenol or Excedrin, among others; prescription medications can too.

Mistaking the proper form of an herb for a health condition for the wrong one, can also, such as mistaking Black Cohosh for Blue Cohosh, if you have a seizure or other neurological condition.

Talking to your doctor and having the proper testing beforehand can mean the difference between a healthy lifestyle or possibly death.   It’s so important to have a few good herbal guide books and reference books before you even consider using herbs.  Many of these books not only list interactions with drugs and other herbs, but they also list interactions with medical conditions.  Here are a few herbs that you must know about before taking any herb or herbal preparation.

Like many prescription and OTC medications, the following herbs can cause seizure disorders or in some cases, hepatitis, still most of these are less harmful than chemical medications


Black Cohosh, Buckthorn, Callilepsis, Cascara Sagrada, Celandine, Chaparral or Creosote Bush, Doxidan or Dioctyl Calcium Sulfosuccinate, Germander, Green Tea Leaf, Groundsel, Impila Root, Jin Bu Huan, Kava, Lobelia, Ma huang or Ephedra, Mate or Paraquay Tea, Mistletoe, Nutmeg, Pau d’arco, Pennyroyal, Poke Root, Ragwort, Sarsparilla, Sassafras, Saw Palmetto, Senna, Skullcap, Some Soy Phytoestrogen, Sweet Clover, Tansy, T’u-san-chi, Valerian, Yohimbe, Woodruff, and Wormwood are just some herbs and extracts that can be harmful if overused or used with various medications.

Because these herbs can be toxic, you should have your physician to do regular liver and blood testing in order to ensure that they are not harming you.  Most of these are fairly safe when used properly, although some, like Skullcap and Valerian are very highly poisonous plants.  They are in many herbal teas and preparations for insomnia, so you should be very careful using such preparations’ and teas if you are on medications for your liver or sleep problems.

Men, Pregnant, menstruating and lactating women should not use the following without your doctor’s advice:  Barbary Root Bark, Cascara Sagrada, Cinnamon, Caraway, Cumin, Chili, Fennel, Feverfew, Juniper Berries, Southern Wood, Pokeroot, Yohimbe, Rue, Oregano, Senna, Tansy, Parsley, Lavender, Peppermint, Mugwort, Nutmeg oil, Sage, Rosemary and Thyme oil and Wormwood, while some of these herbs may be utilized in delivery or getting pregnant, they can potentially cause a miscarriage.  You should read the list of ingredients on any herbal preparation or tea that you buy before using and again, seek your doctor’s advice. 

Many of the above herbs can harm the liver, cause low sperm count, and even make men sterile.  For prostate problems, men may be better off with Saw Palmetto, Nettle Root, Pygeum, Red Clover or Green Tea.

Safer herbs during pregnancy are: Butternut Bark, Butternut Root, Flax Seed, Lemon Balm, Lemon Verbena, Raspberry, Ginger, Dandelion, False Unicorn Root, and Lavender, Wild Yam, Chamomile, Manna and Slippery Elm bark.  These have few or no side effects.

Some herbs can cause eye or vision problems.  Mis-use herbs such as Black Cohosh can clot the blood vessels behind the eyes, cause a mis-shaped curvature of the corneas, even cause an intolerance to contacts.  Other herbs that affect the eyes are: Bilberry, Ginseng, Ginkgo Biloba, Kava Kava, St. John’s Wort, Iodine, Sweet Clover and Grape Seed extract. 

Many of these also help the eyesight, such as Bilberry and Grape Seed Extract, so if you are using any of these to help your vision, you should keep your eye doctor and regular physician well informed so that they can monitor any changes to your eyesight.  There is a good chance that you can use any of these, but better to be overly cautious than to lose your sight.

Never take Chamomile, Lavender, Rose Hips or Valerian if you are already taking a medication for insomnia and be careful when mixing insomnia or muscle-relaxing herbs.  While a little can relax you enough to get to sleep; the wrong mixture or too much, too often can kill you.

There are a number of Oriental herbs that can also cause you harm, such as: Asian Ginseng, Licorace, Dong Quai,  Bai Bu, Da Hui Xiang, Huang Qin, Ma Sang, Ma Bo, Guan Mu, San Qi, Tian Ma, Tian Nan Xing, Shan Si Gu, Shan Dou Gen, Qing U Xiang, Wu Wei Zi,  Artemisia, Gingko and Astralagus among others.

Most Ayervedic’s are fairly safe.  Some of these are: Garlic, Ginseng, Turmeric, Raspberry, Ginger, Echinacea, Aloe Vera, Amalaki, Ashwagandha and Brahmi, while Damiana and Vata Dosha, can cause harm when they are used in the wrong way or dosage.

Some herbs like St. John’s Wort can only be used for a small period of time before it does harm.  It’s important that if you are taking it for a condition, only use it for about 6 weeks at a time, take a break from it for a few weeks and resume use.  Do Not Take this continually!

Herbs that can harm small children are: Chaparral, Comfrey, Germander, Gordolobo Yerba Tea, Jin Bu Huan, Mate Tea, Mistletoe, Margosa Oil, Pennyroyal, St. John’s Wort, Skullcap, Valerian and Wormwood.  Children under 6 years of age should never be given these and those who are older may suffer some side effects if given the wrong doses. 

If you give your child herbs, make sure that you physician, integrative practitioner or holistic specialist knows and can monitor their use and vital signs.

Remember, herbs and natural plant extracts can be very helpful and very safe, providing that you let your physician know that you are using them and that you are being well-monitored for blood, kidney and liver problems. 

If you experience any negative side effects or negative reactions to any herb, you should treat is as any other poison substance and stop using immediately.  Inform your doctor, if available or go to the ER immediately.  You only have one body and it’s better to exercise caution with anything that you ingest.

Purchase some good herbal books and take them with you to the doctor when you are considering the use of an herb, so that together you can make the right decisions for your optimum health. 


 “Back to Eden”, by Jethro Kloss, Published by: Lotus Press, Enlarged 2nd Edition, 2004

 Charles W. Fetrow and Juan R. Avila; Published by: Pocket Books, 2000

 “The Herbal Medicine-Maker’s Handbook: A Home Manual”, By: James Green, Published by: Crossing Press, 2000

More about this author: M. L. Kiser

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