What Is Lobelia, and How Is It Used?

Lobelia is a group of flowering plants native to North America.

Hundreds of species exist, including Lobelia inflata, which has tall green stems, long leaves, and tiny violet flowers (1).

Native Americans in the New England region of the United States used Lobelia inflata for medicinal and ceremonial purposes for centuries. It was smoked and burned to induce vomiting or treat asthma and muscular disorders (1).

This variety of applications earned the plant the nicknames Indian tobacco and puke weed.

Lobelia inflata continues to be used for medical purposes today. Studies indicate that lobeline, its main active compound, may protect against depression, help treat drug addiction, and improve memory and concentration (2, 3, 4).

Lobelia is available loose and dried for making into tea, as well as in capsules, tablets, and liquid extracts. The flowers, leaves, and seeds are used in various preparations.

SUMMARY

Lobelia inflata is a species of lobelia long utilized for medicinal purposes. Its main active compound, lobeline, may help fight asthma, depression, and memory issues.

Lobelias contain several different alkaloids, or compounds that provide therapeutic or medicinal effects. Well-known alkaloids include caffeine, nicotine, and morphine (1).

The most prominent alkaloid in Lobelia inflata is lobeline, which may protect against the following ailments — though more research is needed (1).

Asthma and other respiratory disorders

Lobelia is sometimes used alongside conventional medications to help treat symptoms of asthma attacks, such as wheezing, uncontrollable coughing, and chest tightness.

This is because lobeline may relax your airways, stimulate breathing, and clear mucus from your lungs (1, 5).

Lobelia is also used to relieve pneumonia and bronchitis, two types of lung infections that cause coughing and difficulty breathing, among other symptoms (1).

Even though lobelia is often recommended by both herbalists and physicians to treat asthma and related issues, no human studies have examined its effects on respiratory ailments.

However, one animal study found that injecting mice with lobeline helped fight lung injury by stopping the production of inflammatory proteins and preventing swelling (6).

Though these findings are promising, human research is needed.

Depression

Compounds found in lobelia may also help protect against mood disorders, including depression.

Specifically, lobeline may block certain receptors in the brain that play a role in the development of depression (2, 7).

One animal study in mice revealed that lobeline significantly reduced depressive behaviors and levels of stress hormones in the blood. Another mouse trial suggested that this compound may enhance the effects of common antidepressant medications (2, 8).

Still, human studies are needed to better understand how lobeline affects this condition. Currently, lobelia cannot be recommended as an alternative treatment for conventional antidepressant medications.

Attention deficit hyperactivity disorder (ADHD)

Lobelia may help manage attention deficit hyperactivity disorder (ADHD).

Lobeline may relieve certain symptoms, including hyperactivity and difficulty focusing, by improving the release and uptake of dopamine in your brain (3, 9).

One study involving nine adults with ADHD noted that taking up to 30 mg of lobeline per day helped improve memory over 1 week. However, the results were insignificant (3).

Overall, more human research is necessary.

Drug abuse

Lobelia has been studied as a potential treatment for drug abuse.

Since lobeline has similar effects on your body as nicotine, it has long been considered a possible tool to help people quit smoking.

Still, research on this topic has been mixed, leading the Food and Drug Administration (FDA) to ban lobeline for smoking treatment in 1993 due to the lack of evidence about its efficacy (10, 11).

Nevertheless, some studies indicate that lobeline may be beneficial for other types of drug addictions, as it can interact with brain receptors responsible for the release of neurotransmitters that makes drugs addictive (4, 12, 13).

One animal study in rats addicted to heroin found that lobeline injections of 0.5–1.4 mg per pound of body weight (1–3 mg per kg) decreased the number of times that the rodents tried to inject themselves with heroin (13).

Although preliminary studies are promising, research in this area is lacking. Thus, lobelia cannot be recommended as an effective treatment for any type of drug addiction.

Antioxidant capacity

Compounds in other types of lobelia, especially the alkaloid lobinaline found in Lobelia cardinalis, have been shown to act as antioxidants (14).

Antioxidants are compounds that fight free radicals. These are reactive molecules that can damage cells in your body and increase your risk for illnesses, such as cancer and heart disease (15).

One study found that, in addition to fighting free radicals, lobinaline aided brain signaling pathways (14).

Thus, this compound may play a beneficial role in diseases that stem from free radical damage and affect the brain, such as Parkinson’s disease. However, more research is needed (14).

SUMMARY

Lobeline, the active compound in Lobelia inflata, may help treat asthma, depression, ADHD, and drug abuse, but human research is limited. Compounds like lobinaline in other types of lobelia may have antioxidant effects.

Since research on lobelia is limited, no standardized dosages or recommendations exist.

One study in adults with ADHD suggested that up to 30 mg of lobeline per day in tablet form appears to be safe.

Nonetheless, some side effects include nausea, a bitter aftertaste, mouth numbness, heart arrhythmia, and increased blood pressure (3).

Furthermore, lobelia is known to induce vomiting and can be poisonous — even fatal — in very high doses. Taking 0.6-1 gram of the leaf is said to be toxic, and 4 grams may be fatal (1, 16, 17).

Children, individuals taking medications, and women who are pregnant or breastfeeding should avoid lobelia products due to the lack of safety research.

If you are interested in taking lobelia, be sure to consult with your healthcare provider or an experienced herbalist beforehand.

Keep in mind that supplements are not well regulated by the FDA, so the amount in the product may not match what’s listed on the label. Always choose supplements that have been tested by a third party.

SUMMARY

There are no standardized dosages for lobelia. Taking it in high amounts may lead to nausea, vomiting, and even death. Thus, it’s best to consult with your healthcare provider. Certain populations should avoid it completely.

Lobelia is a flowering plant used for medicinal purposes for centuries.

Some studies show that lobeline, the active compound in Lobelia inflata, may help treat asthma, depression, ADHD, and drug abuse.

However, research in humans is limited, and lobelia may cause adverse side effects or death in very high doses. Since there are limited research and multiple negative side effects, many would recommend avoiding lobelia in most cases.

If you’re interested in taking lobelia, be sure to consult with your healthcare provider to ensure safety.