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Lobelia

Botanical Name: Lobelia inflata

Family Name: Campanulaceae, subfamily Lobeliodeae

Geographic Distribution: Eastern U.S., Eastern Canada, British Columbia.   

Native To: Southeastern Canada (Nova Scotia to southeast Ontario), British Columbia, Eastern U.S. (south to Alabama and west to Kansas), and the Kamchatka Peninsula in Russia (Thomson Healthcare Inc., 2007; “Lobelia inflata”, n.d.)  

TCM Name: Ban Bian Lian (Lobelia chinensis)

Ayurvedic Name: Mrityupushpa or Mriduchhada (Lobelia nicotianifolia)

Common Name: Lobelia, Indian tobacco, pukeweed, asthma weed, bladder pod, obelia, emetic herb, emetic weed, gagroot, vomitwort, tobacco lobelia, wild tobacco   

Botanical Description: Lobelia is an annual, growing as low as 4 inches tall, characteristic of solitary path side plants in compacted soil, or up to 36 inches tall when in patches. You may first notice lobelia when you hear a faint rattle at your shins. These are the inflated seed pods for which L. inflata is named. The flowers are both white and pale blue-violet, split tubular five-petalled, and inconspicuous, a quarter inch at most, and positioned close to the stem and leaves. The stems are yellow-green to dark green, stiff, and hairy to varying degrees, the hairs not usually obvious. Mature plants are paniculately branched with the stems angled upwards near the top of the plant. Younger or smaller plants may be simple in arrangement, with a single stem only. Ovate to oblong leaves are joined close to the stem, sessile or narrowing into a short petiole and arranged alternately. Leaves at largest growing up to 2 ½ inches long near the base of the plant and smaller at the top of the plant. The leaf margin is slightly serrated. (Fischer & Harshbarger, 1941; Foster & Duke, 2014; “Lobelia”, n.d.; Culbreth, 1927)    

Parts Used: Leaf, flower, seed, root, stem

Sustainability Issues: L. inflata is listed by United Plant Savers as a to-watch plant. The United Plant Savers statement for this plant is “Very limited wild harvest is permissible when no other alternative will do” (Gladstar & Hirsch, 2000 p 157). If patches are harvested entirely before seedpods mature and drop seeds, populations could be reduced or eliminated. Wildcrafters are advised to leave some mature plants to re-sow or if seeds are mature scatter those of many plants throughout the habitat. (Gladstar & Hirsch, 2000).    

Harvesting Guidelines: Harvest the entire above ground plant between the end of July and the end of October. If drying dry in shade and the product should be stored out of light, especially if powdered. (Hoffman, 1988; Hutchens, 1992) Care should be taken by harvesters to protect themselves from irritation to skin by excessive exposure or eyes by the slightest exposure. Some species of Lobelia have caused contact dermatitis by commercial harvesters (Idriss et al., 2012).     

Key Constituents: Alkaloids; lobeline, lobelane, lobelanidine, lobelic acid, lobelanine, and isolobinine, a total of least 52 (Laszlo & Szoke, 2015; “Lobelia”, 2014; Folquitto, et. al., 2019), norlobelanine (Thomson Healthcare Inc., 2007); glycoside; lobelacrin; essential oil, labelianin; chelidonic acid (“Lobelia”, n.d.), flavonoids, terpenes, triterpenes, saponins, coumarins, phytosterols (Folquitto, et al., 2019).  

Safety: Lobelia has been regulated in some countries. Lobelia is undefined in the United States as a food ingredient (Leung & Foster, 1996). However it is not included on the U.S. Food & Drug Administration (FDA) Generally Recognized as Safe (GRAS) list (“Lobelia”, 2018). Additionally, the FDA specifically forbids labeling lobelia products for smoking cessation, based on insufficient evidence of efficacy and the possibility for adverse reactions associated with the use of as little as 50 milligrams (“FDA Warning”, 1993; “CFR Code”, 2018). Health Canada prohibits the sale or use of lobelia by all but licensed health professionals and sets an upper limit per single dose of 130.0 mg or 390 mg/day (“Lobelia”, 2014; “Drugs”, 2019). In Australia lobelia has been restricted to licensed medical practitioners (Pengally, 2004).

Common contraindications include infectious or inflammatory GI conditions, hiatal hernia, esophageal varices, stomach ulcers, or peptic ulcers, and speculatively irritable lung conditions due to potential reflexive effects (Brinker, 2010). Lobelia is likely unsafe for consumption during pregnancy and lactation due to its emetic effects (McGuffin, et al., 1997). Excessive use with children, the elderly, or any person with low vitality should particularly be avoided (Brinkner, 2010).  

Overdose could result in the following:

  • Dry mouth

  • Nausea or vomiting

  • Abdominal pain or diarrhea

  • Burning upon urination

  • Anxiety

  • Dizziness or headache

  • Chills and/or sweating

  • Respiratory difficulty

  • Bradycardia

  • Cardiac arrhythmias

  • Drowsiness

  • Muscle twitching

  • Hyperventilation

  • Hyperpnoea

(Thompson Inc., 2007; Stansbury et al., 2013)

Lobelia was listed as an herb that cardiologists should be aware of with respect to involvement in adverse events (Cohen & Ernst, 2010). Safety sources advise against use by any person with the following heart conditions; dyspnea from heart disease, enlarged heart, fatty heart, fluid around the heart, valvular incompetence, arrhythmia; or pneumonia, fluid around the lungs, or high blood pressure, due to the potential for aggravation of these conditions by nervous system effects on the cardiovascular and respiratory system. (Brinkner, 2010)

Extreme overdose may cause convulsions (Wade, 1977). Though it is disputed, administration of lobelia to patients in severe state of disease has been associated with fatality (Martindale, 1982 as cited in Leung & Foster, 1996). Although smaller doses may cause some of these symptoms, 0.6-1 g of leaves has been reported as a toxic dose and 4 grams fatal. However this is extrapolated from research (Gruenwald et al., 1998). There are no confirmed deaths or serious adverse events caused by lobelia (Bergner, 1998).

Clinical herbalist David Winston writes:

“In overdose it can cause nausea, vomiting and respiratory distress, but the effects are transient. Lobelia is a strong herb, best used with a practitioner’s guidance. In normal doses, it is sage and a useful medicinal herb. Traditionally it is used in Native American medicine and was popular with Eclectic and Physio-medical physicians. This herb is used in small amounts or as a minor ingredient in formulas.” (Winston, 2004)  

There are two broad areas for potential drug interaction extrapolated from pharmacology. According to these precautions, large doses should be avoided after:

  • Recent consumption of central nervous stimulants, due to the emetic action and potential to induce convulsions

  • Recent consumption of sedatives, due to the emetic action and potential for aspiration pneumonitis

The source calls these speculative.

(Brinker, 2010)

Toxicology references mention lobelia hardly or not at all, suggesting there are no confirmed reports, while conventional medicine textbooks claim lobelia or lobeline are potentially deadly (Bergner, 1998).  

Though other species of lobelia have been used as an emetic and some other uses overlap, the species are not interchangeable. For example, Lobelia tupa, also known as devil’s tobacco has been used by native people as an anesthetic and hallucinogenic (Paz et al., 2015). However, it contains poisonous latex that causes vomiting and delirium if ingested and topically causes irritation (“Dangerous supplements”, 2010).

The main write-up:

Lobelia inflata, though not notable by its meek appearance, often blending into the surroundings, growing just sparsely, in hardened soil, where other plants prefer not to, such as paths, floodplains and logging landings, has not been overlooked with respect to its actions on the body. It has been involved, in times at stage center, in the history of American herbalism. Through its history to present there was never any doubt that it has actions on the body, however, the safety and appropriateness of using lobelia have been debated. Nineteenth-century eclectic healers and herbalists were sometimes  called “lobelia doctors”, a derogatory term at the time, based on its enthusiastic use among them, and public debate about the safety of this herb (Tyler, 1999). The safest ways to begin to use lobelia are topically or in small amounts in combination with other herbs.

There are five main categories of applications:

  • Emetic, or as a purgative, historically

  • Antispasmodic

  • Expectorant

  • Relaxant to the airway

  • Subtle nervous system effects by small amounts in formula or topical uses

Lobelia inflata and a few other species which are endemic to North America have traditional use among many Native American tribes, including applications of leaves, flowers, seeds, and roots. Eclectic and modern uses reflect many of the traditional ones.

Traditional Native American uses include the following:

Cherokee

  • Analgesic, a poultice of root for body aches and leaves for stiff neck

  • Dermatologic, on bites, stings, sores, and boils

  • Emetic, plant or infusion ingested as a strong emetic

  • Respiratory aid, for asthma, sore throat, or to break a tobacco habit

(Hamel et al., 1975, as cited in Moerman, 2009)

Crow  

  • Ceremonial medicine

(Blankinship, 1905, as cited in Moerman, 2009)

Iroquois

  • Cathartic, as a purgative

  • Psychological aid, for tobacco or alcohol habit

  • Magical, love medicine and protection against misfortune

(Herrick, 1977, as cited in Moerman, 2009)

One of the most interesting Native American magical uses is throwing a bit of powdered lobelia into the air to ward off thunderstorms (“Lobelia”, 2004).   

New Englanders and Europeans used L. inflata for a long time before the 19th-century era of the eclectic physicians (Hutchens, 1992). North American lobelias were brought to Europe in the 16th century for medicinal purpose. The latinized name Lobelia was given by Linnaeus in honor of Matthias de Lobel, a botanist and private physician to King James I (“Lobelia”, 2004).

In the 19th-century medicinal use of lobelia was revived most notably by a charismatic American herbalist Samuel Thompson and it became a symbolic herb of the eclectics. For a half a century or so eclectic physicians, country doctors and herbalists promoted use of lobelia in a variety of ways. In many eclectic texts lobelia is described as a circulatory stimulant or depressant, depending on the dose, and nervous system stimulant or depressant, dependent on dose, with a myriad of specific indications related to the actions. During an era when purging and bloodletting, and mercury preparations were popular in conventional medicine, lobelia was a cathartic remedy used by the range of practitioners, from herbalists and country doctors to medical doctors.  

Samuel Thompson, who as mentioned popularized this herb, was said to use it primarily to induce vomiting in lieu of even more heroic treatments practiced in conventional medicine in that day (“Lobelia”, 2014). Lobelia was also used freely in that time and for a period that followed, as an antispasmodic, and remedy for spastic breathing, as well as in childbirth (Bergner, 1998). In combination with other herbs subtle and complex nervous system effects of lobelia were thought to make the patient more receptive to the remedy. To this day herbalists who use lobelia reserve it for heroic actions or add it in small amounts as an adjuvant, in combination with gentler herbs

Lobelia was central to a famous trial held against Thompson after a very ill patient he allegedly administered it to died. He was acquitted, based on a multitude of factors in the patient’s case, such as errors in the evidence presented and it was also noted that Thompson had had no other fatalities among his patients, despite frequent use of lobelia. It is also unclear from the range of reports whether the herb used was actually lobelia or marsh rosemary, and whether the patient’s advanced state of disease and treatments by a medical doctor also attending the patient could have been the cause of death. Use of lobelia quieted somewhat following this, and another lobelia related trial in 1837, and with the end of administering heroic therapies such as bloodletting and mercurials by conventional medicine. Lobelia was taught in some medical schools and listed as an asthma remedy by the United States Pharmacopeia from 1820 until 1920. (Griggs, 1981 as cited by Bergner, 1998; King, J, 1898)  

In Kings American Dispensatory, a detailed manual of herbs used in American medical practice, first published in 1854 and revised by colleagues for republishing in 1898, the sensation of lobelia is described as acrid, prickling and persistent in the throat, accompanied by slight nausea and warmth in the esophagus and stomach, and profuse salivation. The sensations that followed are best described in a direct quote:   

“A sense of epigastric depression succeeds, followed by profound nausea, and if the amount chewed be large enough, severe and thorough emesis results. The gastric mucus is secreted in great abundance and ejected with the contents of the stomach. The emetic action of lobelia is extremely depressing and is usually accompanied by profuse perspiration. Oppressive prostration, relaxation of the muscular system, and a languid pulse accompany the emetic stage. The depression, however, is of short duration and is immediately followed by a sense of extreme satisfaction and repose. Under its action the mental powers are unusually acute, and the muscles are powerfully relaxed. The circulation is enfeebled by large and strengthened by small doses, and the bronchial secretions are augmented.”

King’s also states that when lobelia does not prove emetic, it usually purges, probably a distinction between inducing vomiting and laxative action. Lastly, this source claims that if death occurs from lobeline it is said to result from respiratory paralysis. (Lloyd & Wickes ,1898)  

As above, the emetic action of lobelia is called depressing. Many sources make the distinction that higher doses are depressant, while small doses are stimulant (Hutchens, 1992; Winston & Kuhn, 2008). Other sources describe the effects of lobeline as being similar to nicotine, first stimulating the central nervous system then depressing it (Tyler, 1993).

Modern use is informed by the old uses, with the exception of emesis. As an emetic it is effective but the emetic dose is considered unsafe (Sollmann, 1948 as cited in Tyler, 1993).  Although preparations similar to those used in the eclectic era are used in some cases, the doses are far more conservative for good reason. When reading passages about lobelia care should be taken to look for terms such as ‘to produce emesis’, or ‘as a purgative’ before forging ahead with the recommended dose.

For example, vinegar of lobelia is described as useful for all the indications for which lobelia is administered, as an emetic one to four drams, and as an expectorant, 5-30 drops. In King’s American Dispensatory suggests combining the expectorant dose with elm or flaxseed. (King, 1854)

Another example from King’s American Dispensatory describes an expectorant syrup made of vinegar of lobelia heated with sugar as pleasant, the volatile properties having been dissipated by heat, and sufficiently active for practical purposes (King, 1854). The recipe is as follows:

Syrup of lobelia:

  • 1 pint vinegar of lobelia

  • 2 pounds sugar

Dissolve with gentle heat, not greater than 180° F, skim off scum, strain while still hot.

This preparation would be expected to be slightly milder in action and flavor than the vinegar or tincture preparations, however, one would not be advised to use the dose indicated in this text, of which it is said:

“To produce emesis, and to bring the system under the relaxing influence of lobelia. The dose is from 1 fluid drachm to ½ fluid ounce.”  (King, 1854 p 1242).

This amount is intended to induce emesis, that is vomiting, which is no longer an advised use of lobelia. Instead this preparation could be used similarly to the tincture or vinegar, or at a just slightly higher dose than that for tincture, because it is a bit milder.  

In the case of the above recipe, a milder action is desired. Older texts suggest that heat diminishes the effectiveness of lobelia, however, modern studies find that lobeline is soluble in hot alcohol. Some of the alkaloids are heat sensitive while others may require heat for extraction. There is some agreement that alcohol, water and acid make the best extraction. (Gladstar & Hirsch, 2000). An oxymel, vinegar and honey preparation, or combination tincture and vinegar would achieve this. In this case one would start with a dose similar to that for tinctures, or a bit higher.

For the tincture, modern herbalists suggest starting with very low doses of Lobelia and working up slowly. Cascade Anderson Geller writes that for some who are very sensitive to the potentially nauseating effects 3-5 drops of a strong tincture can cause discomfort, while others can tolerate 15-30 drops, and for some, nausea dissipates quickly while others feel uneasy for hours after. She uses it often topically, for antispasmodic, pain relieving and relaxing effects, and has not ever found topical application to be nauseating. Modern western herbalists often combine lobelia with cayenne for a longer lasting effect whether for internal or topical use. Quoting Dr. Buter, a nineteenth-century physician: “The effects of lobelia may be compared to a fire made of shavings, which will soon go out unless other fuel is added”. (Gladstar & Hirsch, 2000)    

Current uses include antispasmodic, topically and in small doses internally for skeletal muscles spasm, and also for relaxing smooth muscles as in spastic cough. Lobelia is thought to reduce bronchospasm and lobeline was an important drug for respiratory symptoms for a long period of time (Felpin, 2004 as cited in Folquitto, 2018). This effect has been demonstrated in an animal model (Melendez et al., 1967).

Lobelia is also thought to affect mucous secretion in the digestive and respiratory tracts.

It is considered expectorant, possibly by the mucolytic effects, which is to say its presence or influence may physically thin mucous making it easier to expel. Additionally the constituent lobeline is said to support the cough reflex and improve vascular tone (Stansbury et al., 2013). Specific indications include wet conditions with excessive discharge or congestion, chronic cough with debility, dry spastic cough, dry or wet cough after fever, in other words instances where respiratory tract secretions are either insufficient or in excess (Moore, 1997). Combination with gentler moving herbs such as elecampane, mullein, hyssop, and ginger, or moistening herbs, such as elm or marshmallow may improve tolerance and efficacy (“Lobelia”, 2014; Stansbury et al., 2013).

Though seldom recognized for antimicrobial effects, studies showed antimicrobial activity of ethanolic and methanolic extracts of L. inflata against Klebsiella, Pneumoniae and Staph aureus, and Staph marcescens (Folquitto et al., 2018).  

Lobelia is also antiasthmatic. Lobeline is also reported to inhibit the release of catecholamines from adrenal glands, and stimulate the release of prostacyclin from the lungs, perhaps helpful in maintaining normal breathing during stress (Stansbury et al., 2013). One should not advise asthmatics to rely on lobelia instead of conventional medicine for an asthma attack (Stansbury et al., 2013).

Though the dose is nuanced small doses of lobelia tincture is sometimes useful for stomach spasms. (Moore, 1997; Gladstar & Hirsch, 2000). When informing anyone about Lobelia emphasize the emetic effect and importance of testing a 3-5 drop dose and working up to a 15 drop dose or tolerance.

Additionally, a traditional use during labor, to relax the uterus is still observed by a number of birth workers (Gladstar & Hirsch, 2000). An oral dose is given for the “Specific relaxing effect of lobelia on a rigid cervical os that is thick, doughy, and unyielding” (Felter, 1983 as cited in Gladstar & Hirsch, 2000).

More broadly lobelia is considered a general relaxant, nervous system amphoteric, or adjuvant in formulas. In support of traditional use and historical observation, pre-clinical trials have demonstrated antidepressant effects in mice (Subarnas et. al., 1992).  

The activity of Lobelia on the central nervous system has been attributed to alkaloids, of which at least 52 have been identified from aqueous methanolic extracts (Laszlo & Szoke, 2015). Piperidine alkaloids are the primary type in L. inflata (Folquitto, 2019). Animal studies suggest alkaloids of this type may cross the blood-brain barrier, similar to nicotine, and promote the release of neurotransmitters dopamine and norepinephrine, and another constituent in lobelia may have a sedative effect (Stansbury et al., 2013).

Though lobelia is a stimulant by some actions it is also said to be a general depressant on the central and autonomic nervous systems, and neuromuscular activity (Hoffmann, 2003). The paradoxical action has been explained by contrasting effects of two of the main alkaloids in L. inflata. Lobeline is a respiratory stimulant while isolobenine is a respiratory relaxant (Hoffmann, 1988).

Lobelien binds to nicotinic acetylcholine receptor sites, promoting release of epinephrine and norepinephrine release, and acts as an antispasmodic bronchodilator (Ganora, 2009; Pizzorno, et al., 2008). Additionally, lobeline acts on the carotid chemoreceptors which cause an action of dilation or contraction of the arteries from the neck up (Ganora, 2009). Isolobenine is at least partly responsible for the emetic action of lobelia (Hoffmann, 1988).

Modern medicinal chemists and pharmacologists have recognized lobelia for its potential as a therapeutic for the following; tobacco cessation (though labeling lobelia products for this use is restricted by the FDA), and psychostimulant abuse (Dwoskin & Crooks, 2002). Lobelia and lobeline, being similar in physiological effect to tobacco, and nicotine have been used in smoking blends, tablets, lozenges and gum for the effect of reducing symptoms of nicotine withdrawal (Tyler, 1993). The compound lobeline sulfate was sold over the counter as a smoking cessation aid in the U.S. until 1990 (PDR Network, 1990 as cited in Bergner, 1998).

Research into lobelia compounds for treating substance addiction has been limited to in vitro and animal studies thus far. Results of controlled trials using lobeline for this purpose were not sufficiently convincing for the FDA to support this use (Leung, 1980 as cited in Tyler, 1993). Labeling of lobelia products for smoking cessation has since been banned by the FDA (“FDA Warning”, 1993). Herbal product makers should be advised not to label lobelia products for smoking cessation or deterrence particularly if intended for interstate sale.

Related species have been used traditionally on other continents. In Ayurveda flowers of Lobelia nicotianaefolia have been used in decoction for asthma, bronchitis, and fever. Roots of L. nicotianaefolia have been used for eye diseases and leaves to promote wound healing. It has also been used to treat pain and snakebites. (Kursinszki et al, 2015, Chen et. al, 2010, & Crooks et. al, 2011, as cited in Folquitto et. al, 2019)

Due to the relatively low and precise dose for this herb and side effects, namely nausea and emesis, for all species in the genus, it is not recommended that different species be used interchangeably. Use of any species other than Lobelia inflata is not recommended unless by the precise guidance of a traditional user or another herbalist who is experienced with use of that individual species.  

Lobelia inflata can be grown in a variety of soil conditions. Lobelia will grow in shade if the soil is loamy and rich. In the US it is most often grown in the Pacific Northwest. Seeds should be sown on top of the fine-textured soil kept moist until germination. Water plants approximately twice weekly if conditions are dry. (Gladstar & Hirsch, 2000)

Adult Dose:

  • Fresh Herb: rarely as a poultice for expectorant action or to encourage circulation

  • Topical: Poultice made of moistened powder, or tincture, vinegar or infused oil, often in combination with other herbs such as peppermint or cayenne.*

  • Powder: 50-200mg dried herb.**

  • Tincture: 2-10 drops three times daily 1:2, 40% alcohol, 10% acetic acid, or 5-20 drops daily 1:5, 40% alcohol, 10% acetic acid***, or 0.4-1.6 ml tincture 1:8, 60% alcohol.***   

  • Vinegar: 5-30 drops****

  • Syrup: Use similarly to the vinegar, as an expectorant, prepared from 1 pint vinegar of lobelia: 2 pounds sugar, dissolved with gentle heat and strained while hot.****

  • Tea: 0.5 tsp dried herb in 8 oz water, taken 2-oz at a time, three times daily.***  

  • Capsules: “No more than 10% of a formula: two or three capsules a day of a combination product.”***

Dosage information from *Planting The Future by Rosemary Gladstar and Pamela Hirsch, **The British Herbal Pharmacopeia as cited in Medical Herbalism by David Hoffmann, ***Herbal Therapy & Supplements by Merrily Kuhn & David Winston, and ****King’s American Dispensatory by John King.   

Scientific Research

(an extremely abbreviated sampling - 230 Pubmed results)

Herbal Actions: Antiasthmatic, anodyne, antispasmodic, astringent, bronchodilating, diaphoretic, diuretic, emetic, expectorant, hypnotic, nervine, purgative, rejuvenant, relaxant, rubefacient, secretagogue, anti secretagogue, stimulant

Energy: Moving, warming

Taste: Acrid, bitter, pungent

Preparation Methods: Infused oil, liniment, powder, salve, syrup, tea, tincture

 
heather.jpg

A former foraging frolicker, who aims at answering some of often asked but tougher questions in herbalism, such as, how herbs work and what are the real versus theoretical safety issues.  Heather was not long ago collecting and growing hundreds of medicinal plant species for her small herbal product line: Giving Tree Botanicals.  www.GivingTreeBotanicals.com.  Now in the heart of Boston, she is offering herbal health consultations, classes and informal one on one herbal mentorship for interested persons who have immersed themselves in one or more aspects of herbalism or related topics and want to continue with guidance, regular one on one instruction and encouragement, with the possibility of attending occasional community-building events with other students. Fits your schedule and starts where you are!  

She also teaches Actions and Chemistry for the Vermont Center for Integrative Herbalism, www.VTHerbCenter.org and teaches two for-credit herbal courses, for Johnson State College/Northern Vermont University. She gets a great thrill out of presenting at and simply attending herbal events, from Herbstalk, a bustling educational and community gathering in the Boston area to the annual American Herbalists Guild Symposium and anything in between. She has also begun offering seminars for health professionals, the first of which is called "Supplement Straight Talk" about practical aspects of popular herbs & supplements, and talking to patients about herbs. 

 

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CFR Code of Federal Regulations Title 21. (2018). 1 April, 2018. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=310.544

Cohen, P. & Ernst, E. (2010). Safety of herbal supplements: a guide for cardiologists. Cardiovascular Therapy. Aug;28(4):246-53. doi: 10.1111/j.1755-5922.2010.00193.x.

Crooks, P. (2002). A novel mechanism of action and potential use for lobeline as a treatment for psychostimulant abuse. Biochemical Pharmacology. 63(2):89-98.

Culbreth, D. (1927). A manual of materia medica and pharmacology, seventh ed.. Philadelphia, PA: Lea & Febiger.

Dangerous supplements: what you don't know about these 12 ingredients could

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“FDA Warning” (1993). Society for Science-Based Medicine Wiki. http://sfsbm.org/wiki2/index.php?title=FDA_Warning_(1993)  

Felpin, F. (2004). History, chemistry, and biology of alkaloids from Lobelia inflata. Tetrahedron. 60, 10127-10153, DOI: 10.1016/j.tet.2004.08.010

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