Herbal Toxicity: Dangerous Herbs You Should NEVER Ingest
When it comes to herbal remedies, nature provides incredible natural tools for healing and wellness. However, just because an herb is marketed as a natural product or dietary supplement, doesn’t mean it’s safe for consumption. That’s right, not all herbs are safe for ingestion. Herbal toxicity is something you need to be aware of if you are going to use herbs.
Some herbs contain active ingredients that can lead to dangerous side effects, have toxic effects on vital organs, or serious pharmaceutical interactions.
You may notice that some of these herbs are very popular and highly recommended for specific use. For example, comfrey is incredible for muscle and joint pain. Cohosh can be beneficial for regulating a woman’s menstrual cycles and assisting women struggling to conceive.
These herbs offer powerful medicinal properties and benefits. However, you must approach them with caution. Only use these dangerous herbs internally under the direct guidance and supervision of an experienced herbalist who fully understands their risks and proper applications. In short, do not use these herbs on your own. Let’s dive into these herbs, discuss when and when not to use them, and explore how to work with them safely.
Comfrey (Symphytum officinale)
Herbal Properties:
Emollient (protective to the skin) and vulnerary (used for wound care and inflammation)
Why It’s Dangerous:
Comfrey contains pyrrolizidine alkaloids (PAs). These compounds can build up in the body, even in small amounts, causing significant harm over time. PAs are toxic to the liver and can lead to liver damage or liver failure with improper use. If you are using comfrey internally, you should only be doing so with the close direction and supervision of an herbalist, naturopath, or functional medicine doctor who is experienced and aware of the dangers associated with comfrey.
Traditional Uses:
Comfrey was used in traditional medicines to treat wounds, sprains, and bone fractures. It earned the nickname, “knit bone,” because it is so effective in promoting healing of broken bones, sprains, and wounds due to its ability to stimulate cell growth. Its anti-inflammatory properties make it an excellent option for salves and poultices for skin irritation or muscle aches.
Properties and Risks:
Comfrey’s active compounds are absorbed into the bloodstream, making it unsafe to ingest without supervision and close direction. However, comfrey is safe for topical application in small doses and short-term use. Since the skin is the largest organ in the body and has a significant absorption rate, it should not be used over a large portion of the body, or consistently for a long period of time. Even topically, it can pose a risk if you’re not careful with it.
Do not apply comfrey directly to broken skin to avoid systemic absorption. When wounds go through the healing process, they should heal from the inside out. When comfrey is applied directly to a wound, another concern is the speed at which it supports healing. Comfrey has the potential to help close a wound on the surface before the rest of the wound has healed properly. This can lead to infection and wound complications underneath the surface of the skin.
Safe Preparations:
Comfrey is safe for topical use in ointments, salves, and poultices. Its anti-inflammatory and soothing properties make it excellent for external use on bruises, muscle aches and closed wounds.
Pennyroyal (Mentha pulegium)
Herbal Properties:
Antispasmodic and diaphoretic
Why It’s Dangerous:
Pennyroyal contains pulegone, a compound highly toxic to the liver and nervous system. Pregnant women should avoid pennyroyal entirely in any form, as it can induce uterine contractions and lead to miscarriage.
Traditional Uses:
Pennyroyal was historically used by Native Americans and in traditional medicines as an insect repellent, digestive aid, and abortifacient (inducing miscarriage).
Alternative Uses:
Use pennyroyal as an essential oil for external purposes only, such as in natural insect repellents or aromatherapy. Never ingest pennyroyal essential oil or herbal products containing it. As a weak. infusion or tincture, it can be used to help with menstrual regulation and to induce sweating for viral fevers. If using this herb, use the leaf only and be sure it is very diluted.
Properties and Risks:
Pennyroyal contains pulegone, a compound toxic to the liver and nervous system. Ingesting pennyroyal essential oil, even in small amounts, can lead to liver failure, seizures, and potentially death. It is particularly dangerous for pregnant women because it can cause uterine contractions and miscarriage.
Safe Preparations:
Pennyroyal can be used as a well-diluted essential oil in external applications as a natural bug spray. Never ingest pennyroyal or use it internally.
Cascara Sagrada (Rhamnus purshiana)
Herbal Properties:
Bitter (tastes bitter and has multiple digestive benefits), cholagogue (increases bile production), stimulant, laxative.
Why It’s Dangerous:
Cascara sagrada acts as a strong stimulant laxative, which can cause severe gastrointestinal tract irritation and dependency with long-term use. Large doses can cause extreme diarrhea that leads to dehydration, electrolyte imbalances, and kidney damage.
Traditional Uses:
Cascara sagrada was used by Native Americans as a natural remedy for constipation. Even in current modern times, it remains a common ingredient in over-the-counter laxatives.
Alternative Uses:
Occasional, short-term use of cascara sagrada may be safe under guidance from a well-versed and experienced healthcare provider. Avoid long-term use, and consider safer alternatives like psyllium husk or prune juice for digestive support. Marshmallow root can also provide significant benefits to the balance of the intestinal lining.
Properties and Risks:
Cascara acts as a strong stimulant laxative, irritating the gastrointestinal tract. Long-term use can lead to dependency, dehydration, electrolyte imbalances, and kidney or liver damage. Dependency is not like a “drug addiction”. Addiction in this form refers to the inability to have a bowel movement without the use of this cascara. It should never be used by pregnant women.
Safe Preparations:
If needed, cascara sagrada can be used in small doses for a short amount of time.
Kava Kava (Piper methysticum)
Herbal Properties:
Analgesic, anesthetic, antispasmodic, diuretic, sedative
Why It’s Dangerous:
Kava kava should not be taken in large doses or for an extended period of time. If it is used incorrectly, it can cause major liver issues or even liver failure. Adverse events include fatigue, yellowing of the skin (jaundice), and abnormal liver function tests.
Traditional Uses:
Kava has a long history of traditional uses in Pacific Island cultures for its calming effects during rituals and social gatherings. It has also been used for anxiety, stress, and difficulty falling asleep.
Alternative Uses:
Instead of kava, if you are aiming for help with sleep, try herbs like valerian, chamomile, and passionflower, which provide similar calming effects without the risk of liver damage. Always consult your healthcare team before using any herbal product for anxiety, especially if you are on any other medications.
Properties and Risks:
Kava contains kavalactones, compounds that have a calming effect but can cause liver damage and liver failure with high doses or long-term use. Adverse effects include jaundice, fatigue, and abnormal liver function tests. It can also cause impairment, so do not drive while using kava kava.
Chaparral (Larrea tridentata)
Herbal Properties:
Alterative (blood purifying), anthelminthic (rids worms from the body), antibacterial, anticancer, antioxidant, antiparasitic, antiseptic, bitter
Why It’s Dangerous:
Chaparral contains nordihydroguaiaretic acid (NDGA), which can lead to liver damage, kidney failure, and severe pharmaceutical interactions when taken in large amounts. It has also been associated with adverse side effects like stomach pain, vomiting, and potentially toxic effects on the gastrointestinal tract when taken incorrectly.
Traditional Uses:
Chaparral is traditionally used in herbal preparations for skin conditions and as a tea for detoxification.
Alternative Uses:
Chaparral is used topically for its antibacterial properties. Avoid ingesting chaparral tea or dietary supplements, as its risks far outweigh any potential health benefits.
Properties and Risks:
Chaparral contains nordihydroguaiaretic acid (NDGA), which is toxic to the liver and kidneys. Adverse side effects include abdominal pain, vomiting, and liver damage.
Chaparral interacts with certain pharmaceutical medications, so avoid combining it with detox practices. Pregnant women, as well as individuals with kidney or liver disease, must not use this herb. Chaparral places significant strain on the kidneys as they work to purge toxins from the body. Always prepare it as a tea and drink plenty of water to support kidney function while using it.
Safe Preparations:
Use chaparral topically for its antibacterial and antioxidant properties, but avoid ingesting it unless you are doing so under close supervision from an herbalist, naturopath, or functional medicine doctor with herbal experience.
Black Cohosh (Actaea racemosa)
Herbal Properties:
Analgesic, anti-arrhythmic, antidepressant, antirheumatic, antispasmodic, emmenagogue, hypotensive
Why It’s Dangerous:
It could cause loss of a baby or liver damage if not used correctly
Traditional Uses:
Black cohosh has a long history in Native American herbal practices for cramps, menstrual issues, and mild pain relief. In modern times it is commonly used for menopausal symptoms.
Properties and Risks:
Black cohosh stimulates the uterus to contract and should never be used in pregnancy. The exception to this is sometimes black cohosh is used at the end of pregnancy, but usually, it is one ingredient in an herbal recipe. This should ONLY be used with an experienced herbalist, naturopath, or functional medicine doctor.
Large doses may cause adverse effects like dizziness, headaches, and abdominal discomfort. It is also contraindicated for long-term use. Black cohosh should be limited to avoid liver damage. If you are on blood thinners or other prescription medications, be sure to check to see if black cohosh is safe for you to take.
Safe Preparations:
Use black cohosh in short-term preparations and only under the supervision of a professional who has experience with it.
Blue Cohosh (Caulophyllum thalictroides)
Herbal Properties:
Antispasmodic, emmenagogue, and oxytoxic
Why It’s Dangerous:
It can cause miscarriage or harm a developing baby, as well as cause constriction to the blood vessels.
Traditional Uses:
Historically, blue cohosh was used to stimulate menstruation as well as ease heavy menstrual bleeding and painful periods.
Properties and Risks:
Blue cohosh contains compounds that can cause blood vessel constriction in some people. Vasoconstriction, as it’s called, can cause life-threatening cardiovascular events like a heart attack. In some people, blue cohosh could cause high blood pressure, and rapid heart rate as well. Pregnant women and women trying to conceive should avoid it completely, as it can induce labor and harm a developing baby.
How to Stay Safe with Herbal Remedies
- Always consult healthcare professionals or your healthcare team before using herbs, especially if you take prescription medications or have preexisting health conditions like liver disease or heart disease.
- Avoid herbs with a known history of adverse effects unless guided by an experienced healthcare provider.
- Use herbs as intended; some are best for topical applications or aromatherapy rather than ingestion. KNOW YOUR HERBS!
- Pregnant women and nursing mothers should avoid herbs known for their potential to harm the fetus or infant.
Safety Tips for Herbal Supplement Use
While herbal remedies offer incredible health benefits, some herbs can cause serious side effects, toxic effects on vital organs, or dangerous herb-drug interactions. Understanding their active ingredients, traditional uses, and potential risks can help you make informed decisions about herbal supplement use.
Even though these herbs have clear dangers, they can be used. You can still get the beneficial effects while avoiding the risks associated with these dangerous herbs. Remember, nature provides powerful tools for healing, but some require respect and careful use. If you’re not sure, consult your healthcare team and always prioritize your safety.
If you want to dive deeper and learn about how to safely use dangerous herbs and avoid herbal toxicity, check out The Herbal Collective here.
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