What is Coleus?
Coleus refers to a genus of plants within the mint family (Lamiaceae), with several species having different uses and properties. The most commonly known species are Coleus scutellarioides (the decorative foliage plant, also known as Coleus blumei), and Coleus forskohlii (a plant used in Ayurvedic medicine and for producing the compound forskolin). These species are botanically distinct and have different chemical profiles, a critical detail often lost in discussions about their effects. While C. forskohlii contains the well-studied diterpene forskolin, research has identified different compounds, such as salvinorin A and B, in some varieties of C. scutellarioides, though these findings are not universally confirmed. This diversity is central to understanding why general claims about "coleus" can be misleading.
Is Coleus a Narcotic? A Scientific Perspective
In the strictest sense, coleus is not a narcotic. A narcotic is a substance that induces narcosis (stupor, sedation, or loss of consciousness) and is typically an opioid-based pain reliever or a controlled substance with a high potential for abuse and dependence. Coleus and its active compounds do not fit this pharmacological or legal description. The primary pharmacological component of interest, forskolin, is known for its ability to activate adenylate cyclase, increasing the concentration of cyclic AMP (cAMP) within cells. This mechanism, which affects processes like fat breakdown and cardiovascular function, is not consistent with the effects of a narcotic. Claims of psychoactive effects associated with certain decorative varieties of coleus (C. scutellarioides or C. blumei) have surfaced in anecdotal reports and folklore but are not substantiated by scientific investigation. Many studies have failed to detect significant psychoactive compounds in certain coleus varieties, and existing research often highlights the plant's medicinal rather than mind-altering potential.
The Case of Forskolin from Coleus forskohlii
Coleus forskohlii has a long history in traditional Ayurvedic medicine, and modern science has focused on its active compound, forskolin. Forskolin has been investigated for potential applications related to cardiovascular health, respiratory function, and weight management. Its mechanism of action through cAMP is distinct from the central nervous system depression characteristic of narcotics. Instead, it promotes processes like blood vessel dilation and fat metabolism.
Pharmacological effects of forskolin
- Cardiovascular: Causes vasodilation (widening of blood vessels), leading to lower blood pressure.
- Respiratory: Increases cAMP levels in the lungs, which can relax smooth muscles around bronchial tubes.
- Metabolic: Increases the rate of fat breakdown in fat cells, which is the basis for its use in some weight-loss supplements.
- Other Potential Effects: Research also explores neuroprotective benefits and its effects in treating glaucoma.
The Misconception of Psychoactive Coleus
The idea that coleus is a psychoactive drug largely stems from anecdotes and unsubstantiated claims, particularly regarding the decorative Coleus scutellarioides. Some folkloric accounts and social media reports suggest mild relaxing or hallucinogenic effects, drawing comparisons to plants like Salvia divinorum, which belongs to the same family. However, the psychoactive components in Salvia divinorum (salvinorin A) are well-identified, whereas the alleged psychoactive substances in coleus remain largely a mystery to science. One notable case report from 2016 detailed a psychotic episode in a patient who ingested C. blumei based on social media recommendations, but subsequent lab tests for common illicit drugs were negative. This single case, while noteworthy, does not prove a definitive narcotic effect and contrasts with the majority of scientific literature on the plant. The potential for individual sensitivities or reactions to unknown compounds should not be conflated with a plant being a narcotic.
Coleus vs. Controlled Substances: A Critical Comparison
To understand why coleus is not a narcotic, it is useful to compare its known properties with those of actual controlled substances. The table below outlines key differences.
| Feature | Coleus forskohlii (Forskolin) | Coleus scutellarioides (Psychoactive claims) | Salvia divinorum | Opium Poppy (Morphine/Codeine) |
|---|---|---|---|---|
| Classification | Herbal Supplement (not regulated as a drug in the US) | Plant (not controlled) | Controlled Substance in many jurisdictions | Controlled Substance (Schedule II opioid) |
| Active Compounds | Forskolin (diterpene) | Anecdotal; some studies identify salvinorin A/B but unconfirmed | Salvinorin A (non-nitrogenous opioid agonist) | Morphine, Codeine (alkaloids) |
| Primary Effects | Increases cAMP, affects metabolism, vasodilation | None proven; anecdotal mild relaxation/hallucination | Potent dissociative hallucinogen | Analgesic, sedative, hypnotic (narcotic) |
| Addiction Potential | None documented | None documented | Moderate (for some) | High |
| Overdose Risk | Potential side effects at high doses (e.g., GI issues) | Unknown, but isolated psychotic case reported | Significant risks from potent effects | High, especially from respiratory depression |
Safety Profile and Side Effects of Coleus
While not a narcotic, coleus is not without its side effects, particularly when taken in concentrated forms like supplements. These side effects are generally non-narcotic in nature and relate to its known pharmacological activities, particularly affecting the cardiovascular and gastrointestinal systems.
Common Side Effects of Coleus Supplements:
- Low Blood Pressure (Hypotension): Because forskolin can widen blood vessels, it can cause a drop in blood pressure, which may be dangerous for individuals who already have low blood pressure or take blood pressure medication.
- Bleeding Disorders: Forskolin may increase the risk of bleeding, and anyone with bleeding disorders or who is scheduled for surgery should avoid it.
- Gastrointestinal Issues: High doses can cause side effects such as diarrhea, constipation, and vomiting.
- Other Effects: Inhalation of forskolin powder can cause throat irritation, coughing, tremor, and restlessness.
Conclusion: Reassessing the 'Narcotic' Label
The answer to is coleus a narcotic is a clear no. Scientific and pharmacological evidence, based primarily on the compound forskolin from Coleus forskohlii, shows that the plant's effects are related to its impact on cellular function, not a narcotic action. While anecdotes and folklore persist regarding potential mild psychoactivity from the decorative C. scutellarioides, these claims lack scientific validation and should not be treated as a definitive pharmacological property. The potential for adverse effects, while real, is different from the sedative, addictive, and abuse potential associated with true narcotics. Therefore, it is crucial to distinguish between unproven recreational use and the established medicinal properties of coleus when assessing its safety and classification. For reliable information on herbal supplements, consulting authoritative sources like the National Institutes of Health is always recommended.
