The major active ingredient of lobelia is a substance called lobeline. It is widely stated that lobeline is chemically similar to nicotine, and on this basis it has been marketed as a stop-smoking treatment. However, this belief appears to be a type of urban legend; lobeline is not in fact chemically similar to nicotine.¹

Interestingly, chemists investigating the lobeline–nicotine myth found that lobeline may diminish certain effects of nicotine in the body, specifically nicotine-induced release of the substance dopamine. Since dopamine is believed to play a significant role in drug addiction, these findings can be taken as hinting that lobeline might be useful for treating drug addiction. Potential benefits have been found for addiction to amphetamines.^1,2,3

Dopamine also plays a role in cigarette addiction. For this reason, despite lobeline’s lack of similarity to nicotine, it is at least possible that lobelia could be helpful for people who wish to stop smokeing. Unfortunately, despite its widespread marketing for this purpose, there has never been any meaningful evidence that it works.⁴

Other proposed uses of lobelia also lack supporting evidence. For example, while studies in horses have found that injected lobeline causes the animals to breath more deeply,⁵ it is a long way from a finding like this to the widespread claims that lobelia is helpful for asthma. Similarly, animal studies hint that lobeline might enhance memory⁶ and reduce pain,⁷ and, in addition, that beta-amyrin palmitate, another constituent of lobelia, might have antidepressant and sedative properties.^8-10

However, there have not yet been any human studies on these potential benefits of the herb.

It is widely stated that lobelia is a dangerously toxic herb. However, herbalist Paul Bergner undertook a review of published literature and discovered that each author who described lobelia as toxic was merely quoting another author, in a kind of game of telephone going back nearly 200 years.¹¹ The original published reference upon which this sequence of hearsay reporting appears to have been based is a note in the American New Dispensatory of 1810, in which an “eminent physician” is quoted as stating that if a person consumes lobelia and doesn’t vomit, death will follow. The ultimate origin of this claim may have been the claims made by the prosecution in a widely publicized trial of Samuel Thomson in which he was accused of committing murder through use of lobelia.

In fact, there are no reported cases of death caused by Lobelia inflata in animals or humans. Considering how widely lobelia was used under the Thomsonians and subsequently, the concern that it reliably causes death appears to be a significant overstatement. Lobelia may present health risks, but if so, they have not been documented.

Short-term side effects that have been reported in association with lobelia include stomach pain, heartburn, nausea, vomiting, and dizziness.^12,13 Lobeline also appears to trigger coughing and a sense of choking, for reasons that are unclear.^14-16

The fact that lobeline restricts dopamine release suggests at least a possibility that lobelia could worsen symptoms of Parkinson’s disease (in which dopamine levels are low) and possibly interfere with the action of drugs used for schizophrenia or attention deficit disorder (which also act on dopamine). These concerns are, however, purely theoretical at this time.

Safety in young children, pregnant or nursing women, or people with severe liver or kidney disease has not been established.