Blue Lotus

The two best-characterized alkaloids explain why the flower is pharmacologically active, but not necessarily how a cup of tea affects a person. Apomorphine is a non-selective dopamine receptor agonist at D1 and D2 receptors; in prescription form it is injected under the skin or given sublingually to rescue people with Parkinson's disease from 'off' periods, and it was historically used for erectile dysfunction. It is also a powerful trigger of the vomiting center. Importantly, prescription apomorphine is not given as an ordinary swallowed tablet because oral bioavailability is very low owing to first-pass metabolism, so how much apomorphine survives a blue lotus tea is uncertain. Nuciferine, shared with the sacred lotus, has a receptor profile in laboratory screens that resembles an atypical antipsychotic: it is an antagonist or partial agonist at dopamine D2-like receptors and several serotonin receptors, and in mice it reduces amphetamine-induced hyperactivity. The combination of a dopamine agonist and a dopamine antagonist in the same flower makes the net effect hard to predict and probably dose- and preparation-dependent. The sedation and relaxation that users describe may come from these alkaloids, from flavonoids, or from the alcohol when it is steeped in wine. Concentrating the alkaloids by alcohol extraction or vaporizing a resin delivers far more than the traditional infusion, which is where the adverse-event reports cluster. There are no human pharmacokinetic or receptor-occupancy studies of blue lotus preparations.

Blue lotus has no randomized controlled trials, no dose-finding studies and no formal safety studies in humans; the evidence base is ethnobotany, chemical analysis, pharmacology of the isolated alkaloids and case reports. Ethnobotanical work by Emboden in 1981 and a 2004 commentary in the Journal of the Royal Society of Medicine argued from Egyptian iconography and the plant's chemistry that Nymphaea species were used as ritual intoxicants, though this remains an inference. Chemical analyses of the flowers have confirmed apomorphine and nuciferine among the constituents. In 2017 Poklis and colleagues analyzed a commercial blue lotus 'resin' being used in rebuildable dripping-atomizer e-cigarettes and detected apomorphine and nuciferine, documenting a new route of use. The pharmacology of nuciferine was mapped in detail by Farrell and colleagues in 2016, who found an antipsychotic-like receptor profile and effects on amphetamine-driven behavior in rodents; separate rodent studies of nuciferine from sacred lotus report reduced fat accumulation in the liver and metabolic improvements, none of which has been tested in people. Apomorphine's clinical effects — rapid dopaminergic action, nausea, hypotension, somnolence — are well known from decades of Parkinson's disease use and are relevant warnings. On the harm side, poison-center reports and US military medical bulletins describe altered mental status, agitation, hallucinations and chest pain after vaping or smoking blue lotus extracts; the US Army and Air Force have prohibited its use by service members. Legally, the FDA has not approved blue lotus as a food or supplement ingredient, Louisiana bans its sale for human consumption, and Poland, Latvia and Russia list it as a controlled or prohibited plant. In short, the flower is pharmacologically real, the traditional tea is probably mild, the concentrated products are unpredictable, and nothing about its benefits has been measured.

Aporphine alkaloids apomorphine and nuciferine (plus related minor alkaloids); flavonoids (quercetin and kaempferol glycosides) and anthocyanins responsible for the blue color; the alkaloid content of a given batch is unstandardized and often unknown

The alkaloids are only partly extracted by hot water, better by alcohol, which is one reason wine infusions and tinctures are reported as stronger than tea. Apomorphine taken by mouth undergoes extensive first-pass metabolism in the liver, so most of what is swallowed never reaches the bloodstream — prescription apomorphine is given by injection or under the tongue for this reason. Inhaled or vaporized alkaloids bypass the liver and reach the brain within seconds, which explains why vaped resins produce stronger and less predictable effects than tea. Nuciferine is absorbed orally and crosses the blood-brain barrier in animal studies. Because no product is standardized and alkaloid content varies with growing conditions, harvest and processing, two bags of 'blue lotus' can differ many-fold in potency.

• Dried whole flowers steeped as a tea (the traditional and least concentrated form)
• Flowers steeped in wine (the historical Egyptian practice)