Herbal medicine (also called herbalism, phytomedicine or phytotherapy) is the study of pharmacognosy and the use of medicinal plants, which are a basis of traditional medicine. Scientific evidence for the effectiveness of many herbal treatments remains limited, prompting ongoing regulatory evaluation and research into their safety and efficacy. Standards for purity or dosage are generally not provided.
The scope of herbal medicine sometimes includes fungi and bee products, as well as Dietary mineral, Exoskeleton and certain animal parts.Paraherbalism is the Pseudoscience use of plant or animal extracts as medicine, relying on unproven beliefs about the safety and effectiveness of minimally processed natural substances.
Herbal medicine has been used since at least the Paleolithic era, with written records from ancient Sumer, Egypt, Greece, China, and India documenting its development and application over millennia. Modern herbal medicine is widely used globally, especially in Asia and Africa. Traditional medicine systems involve long-standing, culturally-embedded practices using local herbs, animal products, and spiritual elements. These systems have influenced and contributed to modern pharmacology. Herbalists believe that plants, having evolved defenses against environmental stressors, produce beneficial phytochemicals, often extracted from roots or leaves, that can be used in medicine.
Sick animals often seek out and eat plants containing compounds like and to help purge Parasitism—a behavior observed by scientists and sometimes cited by Folk healer as the source of their knowledge.
Seeds likely used for herbalism were found in archaeological sites of Bronze Age China dating from the Shang dynasty (). Over a hundred of the 224 compounds mentioned in the Huangdi Neijing, an early Chinese medical text, are herbs.
Herbs were also commonly used in the traditional medicine of ancient India, where the principal treatment for diseases was diet. De Materia Medica, originally written in Greek by Pedanius Dioscorides () of Anazarbus, Cilicia, a physician and botanist, is one example of herbal writing used over centuries until the 1600s.
Some prescription drugs have a basis as herbal remedies, including artemisinin, digitalis, quinine and .
According to Cancer Research UK as of 2015, "there is currently no strong evidence from studies in people that herbal remedies can treat, prevent or cure cancer".
, or tisanes, are the resultant liquid of extracting herbs into water, though they are made in a few different ways. are hot water extracts of herbs, such as chamomile or Mentha, through steeping. are the long-term boiled extracts, usually of harder substances like roots or bark. Maceration is the cold infusion of plants with high mucilage-content, such as Common sage or thyme. To make macerates, plants are chopped and added to cold water. They are left to stand for 7 to 12 hours (depending on the herb used). For most macerates, 10 hours is used.
are alcoholic extracts of herbs, which are generally stronger than herbal teas.
Tinctures are usually obtained by combining pure ethanol (or a mixture of pure ethanol with water) with the herb. A completed tincture has an ethanol percentage of at least 25% (sometimes up to 90%).Groot Handboek Geneeskrachtige Planten by Geert Verhelst Non-alcoholic tinctures can be made with glycerin, but it is believed to be less absorbed by the body than alcohol based tinctures and has a shorter shelf life.The exact composition of a herbal product is influenced by the extraction method. A tea will be rich in polar components because water is a polar solvent. Oil, on the other hand, is a non-polar solvent and it will absorb non-polar compounds. Alcohol lies somewhere in between.
Many herbs are applied topically to the skin in a variety of forms. Essential oil extracts can be applied to the skin, usually diluted in a carrier oil. Many essential oils can burn the skin or are simply too high dose used straight; diluting them in olive oil or another food grade oil such as almond oil can allow these to be used safely as a topical. , oils, Liniment, creams, and lotions are other forms of topical delivery mechanisms. Most topical applications are oil extractions of herbs. Taking a food-grade oil and soaking herbs in it for anywhere from weeks to months allows certain phytochemicals to be extracted into the oil. This oil can then be made into salves, creams, lotions, or simply used as an oil for topical application. Many massage oils, antibacterial salves, and wound healing compounds are made this way.
Inhalation, as in aromatherapy, can be used as a treatment.
Although many consumers believe that herbal medicines are safe because they are natural, herbal medicines and synthetic drugs may interact, causing toxicity to the consumer. Herbal remedies can also be dangerously contaminated, and herbal medicines without established efficacy, may unknowingly be used to replace prescription medicines.
Standardization of purity and dosage is not mandated in the United States, but even products made to the same specification may differ as a result of biochemical variations within a species of plant. Plants have chemical defense mechanisms against predators that can have adverse or lethal effects on humans. Examples of highly toxic herbs include poison hemlock and nightshade. They are not marketed to the public as herbs, because the risks are well known, partly due to a long and colorful history in Europe, associated with "sorcery", "magic" and intrigue.
Although not frequent, adverse reactions have been reported for herbs in widespread use. On occasion serious untoward outcomes have been linked to herb consumption. A case of major potassium depletion has been attributed to chronic licorice ingestion, and consequently professional herbalists avoid the use of licorice where they recognize that this may be a risk. Black cohosh has been implicated in a case of liver failure. Few studies are available on the safety of herbs for pregnant women, and one study found that use of complementary and alternative medicines is associated with a 30% lower ongoing pregnancy and live birth rate during fertility treatment.
Examples of herbal treatments with likely cause-effect relationships with adverse events include Consolida (which is often a legally restricted herb), Ayurveda, Genisteae, chaparral, Chinese herb mixtures, comfrey, herbs containing certain flavonoids, germander, guar gum, liquorice root, and Mentha pulegium. Examples of herbs that may have long-term adverse effects include ginseng, the endangered herb goldenseal, milk thistle, senna, Aloe vera, buckthorn bark and berry, cascara sagrada bark, Serenoa, valerian, kava (which is banned in the European Union), St. John's wort, khat, Areca nut, the restricted herb ephedra, and guarana.
There is also concern with respect to the numerous well-established interactions of herbs and drugs. In consultation with a physician, usage of herbal remedies should be clarified, as some herbal remedies have the potential to cause adverse drug interactions when used in combination with various prescription and over-the-counter pharmaceuticals, just as a customer should inform a herbalist of their consumption of actual prescription and other medication.
For example, dangerously low blood pressure may result from the combination of a herbal remedy that lowers blood pressure together with prescription medicine that has the same effect. Some herbs may amplify the effects of anticoagulants. Certain herbs as well as common fruit interfere with cytochrome P450, an enzyme critical to much drug metabolism.
In a 2018 study, the FDA identified active medication in over 700 analyzed dietary supplements sold as "herbal", "natural" or "traditional". The undisclosed additives included "unapproved antidepressants and designer steroids", as well as prescription drugs, such as sildenafil or sibutramine.
In 2015, the New York Attorney General issued cease and desist letters to four major US retailers (GNC, Target, Walgreens, and Walmart) who were accused of selling herbal supplements that were mislabeled and potentially dangerous. Twenty-four products were tested by DNA barcoding as part of the investigation, with all but five containing DNA that did not match the product labels.
In the European Union (EU), herbal medicines are regulated under the Committee on Herbal Medicinal Products.
In the United States, herbal remedies are regulated dietary supplements by the Food and Drug Administration (FDA) under current good manufacturing practice (cGMP) policy for dietary supplements. Manufacturers of products falling into this category are not required to prove the safety or efficacy of their product so long as they do not make 'medical' claims or imply uses other than as a 'dietary supplement', though the FDA may withdraw a product from sale should it prove harmful.
Canadian regulations are described by the Natural and Non-prescription Health Products Directorate which requires an eight-digit Natural Product Number or Homeopathic Medicine Number on the label of licensed herbal medicines or dietary supplements.
Some herbs, such as cannabis and coca, are outright banned in most countries though coca is legal in most of the South American countries where it is grown. The Cannabis is used as a herbal medical cannabis, and as such is legal in some parts of the world. Since 2004, the sales of ephedra as a dietary supplement is prohibited in the United States by the FDA, FDA Issues Regulation Prohibiting Sale of Dietary Supplements Containing Ephedrine Alkaloids and Reiterates Its Advice That Consumers Stop Using These Products and subject to Schedule III restrictions in the United Kingdom.
Unethical practices by some herbalists and manufacturers, which may include false advertising about health benefits on product labels or literature, and contamination or use of fillers during product preparation, may erode consumer confidence about services and products.
Phytochemical researcher Varro Eugene Tyler described paraherbalism as "faulty or inferior herbalism based on pseudoscience", using scientific terminology but lacking scientific evidence for safety and efficacy. Tyler listed ten fallacy that distinguished herbalism from paraherbalism, including claims that there is a conspiracy to suppress safe and effective herbs, herbs cannot cause harm, whole herbs are more effective than molecules isolated from the plants, herbs are superior to drugs, the doctrine of signatures (the belief that the shape of the plant indicates its function) is valid, dilution of substances increases their potency (a doctrine of the pseudoscience of homeopathy), astrological alignments are significant, animal testing is not appropriate to indicate human effects, anecdotal evidence is an effective means of proving a substance works and herbs were created by God to cure disease. Tyler suggests that none of these beliefs have any basis in fact.
In Andes healing practices, the use of , in particular the San Pedro cactus ( Echinopsis pachanoi) is still a vital component, and has been around for millennia.
Though possibly influenced by Indian Ayurveda systems, the Indonesia archipelago holds numerous indigenous plants not found in India, including plants similar to those in Australia beyond the Wallace Line. Jamu practices may vary from region to region, and are often not recorded, especially in remote areas of the country.
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