Are Herbal Remedies Safe and Effective?

by , | Last updated Jan 11, 2024 | Herbal Remedies

The wide array of phytochemicals in many herbs can help to prevent, ease, and aid in healing common ailments, but they can become dangerous if used inappropriately. Even safe herbal remedies have cautions and contraindications. This blog provides good insights that every individual who uses herbal remedies should know!

Get the Right Herb for the Diagnosis!

One’s persistent cough might not be chronic bronchitis. It just might be a sign of allergies, heart failure, gastric-reflux disease, or lung cancer. Getting an adequate diagnosis is essential for prescribed medicine, and just as essential for the correct use of botanical agents and other natural remedies. Use of an herb should not substitute for medical evaluation or medical treatment. A health care professional should evaluate frequent, chronic, or acute symptoms. Rely on conventional medicine for emergency treatment or serious infections.

Not All Herbs Are Safe.

Many herbs are safe when used appropriately while others are not. They can be divided into three categories: food plants, medicinal plants, and poisonous plants. Nutritionist Winston Craig, PhD. observes: “Whereas some herbal products may be safe and may contain active constituents that have beneficial physiologic effects, others may be unsafe to use. The Food and Drug Administration has classified several herbs as unsafe, even in small amounts, and hence they should not be used in either foods or beverages.”1 Some herbs are safe in modest amounts but they may become toxic at higher doses.

Take licorice for example. It has some wonderful properties. This herb is useful in combatting inflammation, helpful for gastric ulcers, and possesses anti-viral agents.2 Deaths from its excessive use have been reported. Large amounts of licorice can cause serious side effects such as low potassium) high blood pressure, and heart failure. Why? Because licorice contains the compound glycyrrhizin. Therefore, before buying licorice supplement, one would want to be sure it has no glycyrrhizin.

Evaluate the Studies!

Since not all herbs have been evaluated thoroughly, when discussing an herb’s virtues, we need to qualify, “many studies”, “a few studies”, “animal studies”, “human studies”, “traditional use”. Randomized and control studies are the best. Some herbs might make a person feel better because of the placebo effect.

One must read the scientific claims behind the claims made for any herbal remedy. Not all herbs have been studied extensively. Some have, like garlic and curcumin in turmeric. In vitro studies (test tube or in a petri dish) and in vivo (inside a living organism or animal) are helpful. Of the two, in vitro tests only suggests early evidence. The internal environment is so much more complex than isolated cells.

In vivo studies provide somewhat stronger evidence. Many herbs have been studied using animals (often rodents). While these studies are useful, it is unwise to think we should base our treatment decisions upon a few small studies consisting of in vitro and in vivo that have not been validated in human studies. Random controlled trials provide stronger evidence. For health advocates to urge herbal supplements to treat cancer based upon only a couple of in vitro tests is unwise.

Adulterated Herbs Can Kill.

A former student of mine, while in China, developed a simple infection. She was given some Chinese herbs and died shortly thereafter because of adverse effects of the herbs. Those herbs were probably adulterated. Please, for serious problems, see a medical doctor and do not purchase herbs from questionable sources.

A Safe Herbal Remedies Isn’t for Everyone.

Jim became ill with a respiratory infection. He went to the store and asked, “What was a good herb to take for infection?” He took garlic capsules and that night as he walked to the bathroom, he fainted. You see, Jim had a history of low blood pressure. Garlic lowers blood pressure. Some well-meaning clerk gave the right information to the wrong person. Garlic does bolster the immune system. Unfortunately, the clerk did not know its contraindications or the student’s medical history.

Garlic and gingko biloba are usually safe. Mrs. C went to her dentist for a tooth extraction. She had been placed on garlic for mild hypertension. When the dentist pulled her tooth, it took several hours to stop bleeding. Being an elderly woman, she forgot to tell him she was on garlic, which has some anticoagulant factors. Chamomile helps one to relax but it can cause allergic symptoms in a person allergic to ragweed.

Good Herbs & Wrong Diagnosis

Sam had a history of digestive problems. He recently underwent surgery in Chattanooga for a peptic ulcer. For a little while he improved. As his teacher, I watched Sam. One day about 3 months from his surgery, I saw him and was alarmed at how pale he was. He said that he was trying some anti-ulcer herbs like aloe vera and licorice root that someone had recommended.

I took him by the hand, led him to the clinic, and announced, “Neither Sam nor I would be leaving until he saw Dr. Smith.” The doctor diagnosed him as having a bowel obstruction. That night he had emergency surgery. Another week and he would have been dead. Persistent symptoms need to be addressed by competent medical professionals. A second opinion is sometimes necessary. You can bet I was thankful to God that he used me to help Sam. When the right diagnosis and treatment are incorrect, even use of prescribed herbs can delay lifesaving action. We would do well to look up the cautions and contraindications of any herb someone recommends to us.

Safe Herbs Can Exert Undesirable Consequences.

Even a safe herb like peppermint can have adverse effects for certain individuals. The herb peppermint is great for nausea, but substantially reduces iron absorption and relaxes the lower esophageal sphincter. Therefore, individuals who have either iron-deficient anemia or gastro-esophageal reflux disorder should not use peppermint.

Tannins in tea and coffee reduce non-heme iron absorption from a meal, approximately by 60% and 40% respectively.3 Black tea, peppermint, and coca reduce its absorption considerably more.4 Many researchers have studied curcumin from turmeric and ginger extensively. Remarkable for its cancer-fighting and anti-inflammatory effects, curcumin is an extremely useful supplement. High dosages of curcumin can cause iron-deficiency anemia especially if there is marginal iron intake from the diet or other risk factors for iron-deficiency anemia exist.5

Comfrey is another example. The internal use of comfrey damages the liver, but the external application of comfrey might help to heal an uncomplicated skin ulcer when applied topically. Beware of herbal advice from anyone who does not know your medical history.

Proceed with Caution.

Because herbs have possible drug-herb interactions and there might be contraindications for certain medical conditions, one cannot prescribe herbs without knowing the full medical history of a person. You need to know the medicine he takes and their allergies. People allergic to daisy, asters, ragweed, or chrysanthemums should avoid herbal products made of marigold, chamomile, and yarrow flowers.

Safety First!

Refrain from considering herbal products as panaceas (cure all). No herbal products can substitute for good lifestyle habits. When someone advocates a certain herb for so many conditions, run the opposite way. Use herbal products that have only safe ingredients. Read labels carefully. Organically grown herbs are preferred.6,7

Drink no more than one cup of tea a day since most herbs have not been studied long-term. Do not overuse medicinal herbs. It is important to note that every good plant, if used in an inappropriate manner, can cause harm. More is not necessarily better. (Follow the dosages on the labels and be guided accordingly.) Dosages differ depending on the form available to you, such as the herb per se, capsules, tablets, tea extracts, or tinctures.


Herbs should be stored in dark containers and kept in a cool place as light, heat, oxidation, and humidity may destroy some of the active phytochemicals in herbs. Loose herbs sold in bulk have probably lost much of their potency. The same is true for many herbal capsules unless they have standardized ingredients and an expiration date. Tinctures (alcohol-free) and freeze-dried herbs are best. When buying herbal capsules, be sure they have the standardized active phytochemical listed. For example, turmeric capsules should have a standardized amount of curcumin in them. Recognize that some herbal products have been contaminated and are not the pure herb. Therefore, buy from reliable dealers and be sure the active ingredients have been standardized. When an herb begins to lose its color, it is losing its potency fast. Example: The curcumin in turmeric is yellow orange. Brown turmeric is worthless.


Herbal remedies can be effective for simple, common, and brief ailments. Sometimes they are useful as an adjunct treatment for chronic diseases. Properly prescribed herbs coupled with lifestyle interventions, can be useful adjunct treatment for chronic conditions if the right herbs are used for properly diagnosed diseases. No herbal remedy can substitute for lifestyle practices as a whole-plant based diet, daily exercise, good hydration, adequate sleep, etc. Neither should herbal knowledge replace medical counselling. Individuals who are taking any medication should discussed herbal remedies with their pharmacists before using medicinal amounts of any herb or herbal product to avoid possible drug-herb interactions. Pregnant or lactating women should also consult with their health care providers before using medicinal herbs.

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© 2024, Wildwood Sanitarium. All rights reserved.

Disclaimer: The information in this article is educational and general in nature. Neither Wildwood Lifestyle Center, its entities, nor author intend this article as a substitute for medical diagnosis, counsel, or treatment by a qualified health professional.


  1. Craig. Health promoting Properties of Common Herbs. The American Journal of Clinical Nutrition, Volume 70, Issue 3, September 1999, Pages 491s-499s,doi.org/10.1093/ajcn/70.3.491s
  2. Hossein Hosseinzadeh. Pharmacological Effects of Glycyrrhiza spp. and Its Bioactive Constituents: Update and Review. Phytotherapy Research. Vol. 29: 12. December 2015. Pages 1868-1886. onlinelibrary.wiley.com/doi/abs/10.1002/ptr.5487
  3. Hurrell RF, et al., Inhibition of non-haem iron absorption in man by polyphenolic-containing beverages. Br J Nutr. 1999 Apr; 81(4):289-95. www.ncbi.nlm.nih.gov/pubmed/10999016
  4. Tuntipopipat S. Inhibitory effects of spices and herbs on iron availability. Int J Food Sci Nutr. 2009; 60 Suppl 1:43-55. www.ncbi.nlm.nih.gov/pubmed/18651292
  5. Smith TJ. Iron Deficiency Anemia Due to High-dose Turmeric. Cureus. 2019 Jan 9;11(1):e3858. www.ncbi.nlm.nih.gov/pubmed/30899609
  6. Witczak A. Tracking residual organochlorine pesticides (OCPs) in green, herbal, and black tea leaves and infusions of commercially available tea products marketed in Poland. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2018 Mar;35(3):479-486. www.ncbi.nlm.nih.gov/pubmed/29210611
  7. Naithani V. An evaluation of residual organochlorine pesticides in popular Indian herbal teas. Arch Environ Health. 2004 Aug; 59(8):426-30. www.ncbi.nlm.nih.gov/pubmed/16268119

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