“”Herbal medicine: giving patients an unknown dose of an ill-defined drug, of unknown effectiveness and unknown safety.
Herbal supplements are non-pharmaceutical, non-food substances marketed to improve health. Herbalism (herbal medicine, botanical medicine) is the use of plant-derived substances, and sometimes other environmental substances, to treat or cure medical conditions. The idea is that pre-industrial cultures had a great deal of practical medical knowledge, most of it botanical, and herbalism seeks to make use of this.
Definitions are problematic. There are no unified practices, no enforceable standards for strength or purity, and relatively few guidelines for practitioners. Also, there is no clear definition of what a "herbal remedy" is. A large number of currently available drugs are originally plant-derived, which means herbalism is basically pharmacology's petulant, stubborn great grandmother.
The main problem is that, even when the stuff does in fact work, doses, purity and so on are greatly inconsistent and there is very little regulation. For instance, in one study, researchers analyzed 44 herbal medicine products from 12 companies and found that of these, 59% contained herbs that were not on the label, 32% did not contain the herb that was on the label, and 21% contained fillers such as wheat, soybean, alfalfa, and rice. Several products were contaminated with feverfew (Tanacetum parthenium), which can cause "swelling and numbness of the mouth, oral ulcers, nausea, vomiting, abdominal pain, diarrhea, and flatulence". One of the products was labeled as containing St. John's wort (Hypericum perforatum), but did not contain any; instead, it contained senna (Senna spp.), a laxative that can cause "chronic diarrhea, cathartic colon, liver damage, abdominal pain, epidermal breakdown and blistering". A New York State Attorney General investigation found that 78% of the products it tested did not contain the substance listed on the label, and similarly found significant contamination with other, unlabeled ingredients.
Humans have used botanicals for medicinal purposes as far back as archaeological evidence exists. About 30% of all FDA-approved drugs are derived from botanical sources. Examples include aspirin (from willow bark) and digoxin (from the foxglove plant, Digitalis spp.). Molecular biology has allowed for more directed drug development. For instance, the active ingredient in a plant extract can be identified, isolated, and replicated (this is desirable because plants can have extremely variable amounts of the substance in question; for instance, willow bark can contain from 0.08% to 12.6% of its active ingredient salicin.) The molecule can also be modified to add desired effects or eliminate undesired effects. Sometimes molecules are altered in order to develop a drug just different enough from the old medication to allow a new patent to be issued. "Reverse" development is also done, where a receptor in the body is identified, and computers assist in identifying molecules to fit these receptors. In sum, many modern medicines started as plant extracts and were refined to improve the medicinal characteristics, including reducing toxicity.
Currently, approximately 12-25% of Americans use an herbal remedy yearly. Despite their popularity, these substances, advertised as medically active, are regulated as dietary supplements, rather than as medicines, by the FDA. This means that there is very little regulation of the manufacturing or content of these substances. In Canada every natural product must apply for a natural product number (NPN) and is now governed under the Natural Health Product Regulations, which include provisions on adverse reaction reporting, labeling, and site and product licencing.
Americans, however, often perceive herbals as "safer", "more natural", and "more holistic" than conventional medications. Many are also suspicious of the profit motive of the pharmaceutical industry; of course, herbal medications represent an enormous financial interest as well. Echinacea alone has annual sales of about $300 million in the U.S.
Many studies have been done of herbal medications. Unfortunately they often lack good documentation, quality, and suffer from not having analyzed the substance studied. Because of the lack of quality control and regulation, it is difficult to assess what the effect of many herbs is, or even what people may be taking, given the label often fails to match the content.
Given these limitations, a summary of studies of some popular supplements is listed below:
- Milk Thistle (Silybum marianum) seems to have proven results in reducing liver inflammation in children undergoing chemotherapy. Also massive doses of it can save the liver and therefore the lives of victims of Death Cap poisoning. 
- Ginkgo (Ginkgo biloba) is sold as a "memory aid" and a treatment for Alzheimer's disease. Studies show mixed results, with a possibility of it being better than placebo
- Saw palmetto (Serenoa repens): marketed as a treatment for benign prostate disease in men, studies show some effect greater than placebo, at least in the short term.
- St. John's wort: used for depression; data show short-term efficacy over placebo for mild to moderate depression. (May cause cataracts, though this has not been established.)
- Ginseng (Panax spp. and Eleutherococcus senticosus): many different types, insufficient data.
- Echinacea: marketed for the common cold; no good, consistent studies have been done.
- Evening primrose oil (Oenothera biennis): for PMS and eczema; studies show no benefit.
- Ginger (Zingiber officinale): shown in most studies to be better than placebo at preventing nausea and/or vomiting, but still outperformed by conventional anti-nausea medications.
- Garlic (Allium sativum): There is substantial evidence garlic has many health benefits; it's anti-bacterial and anti-fungal. It's also claimed to help with colds and heart health. Thins blood which is good for hypertension but may also increase the amount of bleeding when cut. Garlic has been shown in recent studies to reduce the growth and proliferation of colon tumors although these claims have been challenged. 
- Kava-Kava (or just Kava) (Piper methysticum): marketed for anxiety, some improvement over placebo. Side effects include liver damage and death.
- Valerian root (Valeriana officinalis): for insomnia: does nothing. Rarely, it may actually cause insomnia.
- Cranberry juice (Vaccinium spp.): for prevention of urinary tract infections: not recommended as there was no statistical difference vs. control in a meta-analysis.  There is no demonstrated efficacy for the treatment of UTIs. Also a very good source of Vitamin K and therefore can help with minor clotting disorders.
- Rose Hips (Rosa spp.): Good for getting an extra dose of Vitamin C, but unproven for anything else.
For a more detailed description see list of medicinal plants.
People are not fundamentally stupid, so why do people start using herbal supplements and other forms of "alternative" medicine? It probably has to do with the dangers of prescription medication: According to the U.S. Centers for Disease Control and Prevention, one person dies from a drug overdose every 19 minutes. About 28,754 Americans died after accidentally overdosing on legal or illegal drugs in 2009, according to the CDC; about half of those deaths involved prescription painkillers. Those numbers are significant enough to make prescription drugs one of the leading causes of accidental death in this country. It's a statistic that has led some experts to call prescription drug abuse an epidemic. However, just because there is a reasonable justification for wanting "alternative" medicine does not mean that it will work, or that you should try to sell it to anyone if it does not work.
 Potential harm
Much of the time, herbal remedies are used without consulting a physician about the condition in question. This may lead to delay or failure in diagnosing important medical conditions. For example, a man who takes saw palmetto for his urinary problems may have all the signs and symptoms of prostate cancer, but if he feels better after taking the saw palmetto, he may not be diagnosed until it is too advanced for treatment. Herbs can also interfere with conventional medications.
As herbs have become more popular, and as more have become available with globalization, more toxic effects are being seen. Herbal preparations may or may not resemble the traditional cure from which they were derived, and are often used in a different context. For instance, small amounts of ma huang (Ephedra sinica) may exist in certain Chinese medicines for treating common colds and influenza, but it was used in much higher concentrations in Western weight-loss drugs. Many common herbs can be quite toxic, and may exist in supplements without clear labeling. For example, ma huang can cause serious cardiac disturbances, ginseng (Panax ginseng) can aggravate high blood pressure, and kava (Piper methysticum) can injure the liver. New reports come out regularly about liver failure caused by herbal remedies. Herbal remedies from outside the U.S. are sometimes contaminated with lead and other heavy metals. Some herbal medicines are carcinogenic either in whole (e.g. birthwort and betelnut) or some of their chemical components (e.g. dong quai and sassafras).
Many herbal medicines can interfere with conventional medications. For example, St. John's Wort is a potent inducer of the cytochrome P450 System. This can increase the rate at which the liver metabolizes drugs, leading to a dangerously low level of the drug in the body.
See also this list of medicinal herbs (quite a few of which can cause liver damage).
 Some typical woo
- "Experienced wine drinkers can tell the difference in taste between an expensive and inexpensive wine, but chemical analysis would probably not indicate much of any difference. In the same way an herbal tincture that is well prepared from whole plants by a knowledgeable person provides a medicine that is not able to be chemically analyzed as different, but is far superior to anything standardized on the basis of an ingredient that may not even be active."
That chuckling sound you hear distantly to the east is Hervé This laughing his ass off at the above assertion.
 A comedian sums it all up
Esteemed Irish comedian Dara Ó Briain summarizes the matter succinctly:
“”I'm sorry, 'herbal medicine'. People say, 'Oh, herbal medicine's been around for thousands of years!' Indeed it has, but then we tested it all and the stuff that actually worked became 'medicine'. The rest of it is just a nice bowl of soup and some potpourri, so knock yourself out.
It is interesting to note that organisations selling herbal remedies will almost always make a statement along the lines of "natural is safe." This statement takes many different forms, but is usually directed as a slur to the pharmaceutical industry claiming that OTC and prescription drugs are secretly harmful but because their products are naturally derived, no ill effects can be possible. Basic knowledge of toxicology will quickly refute this generalised claim, as almost all of the most toxic substances on earth are natural in derivation.
Many herbal remedies have significant medical effects. Labeling may not correctly describe the contents of the medication. The preparations available are not well-regulated or well-studied. As such, they are often wasteful, or even toxic. When there is a measurable effect, it is often more modest than the available conventional medicines. Many companies are doing large scale testing of botanicals to look for biologically active substances. Older remedies, and new ones, as discovered, should be subject to the same scrutiny as any other medication. There is no reason to believe that herbal remedies have any "natural" advantage over conventional ones. Randomized controlled trials can distinguish good medicines from bad, independent of the source.
 See also
- Graphic of herbal supplements arranged by level of scientific support
- The only "herbal supplements" confirmed by the FDA not to be placebos
- ↑ Patients’ guide to Magic medicine
- ↑ The term "supplement" allows them to avoid medical laws, while still allowing "health benefits" to be promoted. See Kabat, Geoffrey, "Natural Does Not Mean Safe": in Slate, 2012 Nov 26.
- ↑ The United Kingdom has a National Institute of Medical Herbalists, who have a code of ethics
- ↑ 4.0 4.1 DNA barcoding detects contamination and substitution in North American herbal products, Newmaster et al.
- ↑ Herbal Supplements Not as Advertised
- ↑ Sardesai, Vishwanath M. Herbal medicines: poisons or potions?. Journal of Laboratory & Clinical Medicine. 139(6):343-8, 2002 Jun.
- ↑ Variability in the composition of anti-oxidant compounds in Echinacea species by HPLC
- ↑ Willow bark, University of Maryland Medical Center.
- ↑ Bent, Stephen. Ko, Richard. Commonly used herbal medicines in the United States: a review. American Journal of Medicine. 116(7):478-85, 2004 Apr 1.
- ↑ About Natural Health Product Regulations; Health Canada webiste
- ↑ Bent, Stephen. Ko, Richard. Commonly used herbal medicines in the United States: a review. American Journal of Medicine. 116(7):478-85, 2004 Apr 1.
- ↑ Gagnier, Joel J. DeMelo, Jaime. Boon, Heather. Rochon, Paula. Bombardier, Claire. Quality of reporting of randomized controlled trials of herbal medicine interventions. American Journal of Medicine. 119(9):800.e1-11, 2006 Sep.
- ↑ Wolsko, Peter M. Solondz, David K. Phillips, Russell S. Schachter, Steven C. Eisenberg, David M. Lack of herbal supplement characterization in published randomized controlled trials. American Journal of Medicine. 118(10):1087-93, 2005 Oct.
- ↑ De Smet, Peter A G M. Institution. Herbal remedies. New England Journal of Medicine. 347(25):2046-56, 2002 Dec 19.
- ↑ http://www3.interscience.wiley.com/journal/123211007/abstract?CRETRY=1&SRETRY=0
- ↑ http://www.medpagetoday.com/HematologyOncology/Leukemia/17506
- ↑ http://www.sciencebasedmedicine.org/milk-thistle-and-mushroom-poisoning/
- ↑ http://www.fordham.edu/campus_resources/enewsroom/archives/archive_208.asp
- ↑ http://www.umm.edu/altmed/articles/ginger-000246.htm
- ↑ http://www.ncbi.nlm.nih.gov/pubmed/10793599
- ↑ http://www.ncbi.nlm.nih.gov/pubmed/11697022
- ↑ Garlic as a Possible Risk for Postoperative Bleeding. Burnham, Bruce E. M.D.
- ↑ http://ajcn.nutrition.org/content/84/5/1027.long
- ↑ http://www.ncbi.nlm.nih.gov/pubmed/20924970
- ↑ http://www.webmd.com/cancer/news/20090105/garlics-cancer-benefits-challenged
- ↑ Kava, WebMD. Accessed on the 15th of December, 2012.
- ↑ Taibi DM, Landis CA, Petry H, Vitiello MV. "A systematic review of valerian as a sleep aid: safe but not effective." Sleep Med Rev. 2007 Jun;11(3):209-30.
- ↑ Valerian, WebMD.
- ↑ Jepson, RG; Williams, G; Craig, JC (17 Oct 2012). Jepson, Ruth G. ed. "Cranberries for preventing urinary tract infections". Cochrane database of systematic reviews (Online) 10: CD001321.
- ↑ How Cranberry Juice Can Prevent Urinary Tract Infections, ScienceDaily, 25 July 2008
- ↑ Cranberry juice reduces recurrent urinary tract infection, British Medical Journal, 30 June 2001
- ↑ http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6101a3.htms_cid=mm6101a3_w
- ↑ Ephedra, WebMD.
- ↑ Herbal Remedies: Adverse Effects and Drug Interactions, MELANIE JOHNS CUPP. Am Fam Physician. 1999 Mar 1;59(5)1239-1244.
- ↑ Ginseng, WebMD.
- ↑ Kava, WebMD.
- ↑ Contaminated Herbal Medicine Products, Lead Poisoning Prevention Program, New York City Department of Health and Mental Hygiene, archived by the Wayback Machine.
- ↑ Folk Medicine, Sources of Lead, Centers for Disease Control and Prevention
- ↑ Wang Z, Gorski JC, Hamman MA, Huang SM, Lesko LJ, Hall SD. The effects of St John's wort (Hypericum perforatum) on human cytochrome P450 activity. Clin Pharmacol Ther. 2001 Oct;70(4):317-26.
- ↑ http://natureworksbest.com/herbalmedicine
- ↑ Hervé This, author of Molecular Gastronomy (or its much better French title, Casseroles et Éprouvettes = "Saucepans and Test Tubes") is a French research chemist who is considered the founder of molecular gastronomy as a science. He should be on your cookbook shelf right next to Corriher, Brown, Wolke, and McGee.
- ↑ Examples include botulinum toxin ("Botox"), Ricin, Strychnine, Atropine, Cyanide, and Amatoxins.
- ↑ Koretz, Ronald L. Is alternative medicine alternative science? Journal of Laboratory & Clinical Medicine. 139(6):329-33, 2002 Jun.