Boldine

Boldine at a Glance

Boldine is the principal aporphine alkaloid of boldo (Peumus boldus), a Chilean tree whose leaf is a traditional digestive and liver remedy.

For thirty years it was studied as a radical-scavenging antioxidant — among the more effective natural ones by direct assay — with preclinical hepatoprotective, choleretic, anti-inflammatory, antidiabetic and neuroprotective activity. Over the last decade the field has converged on something more specific: boldine blocks connexin hemichannels without closing gap junctions, a rare pharmacology that may account for most of what it does in animals.

Boldo leaf’s safety caution comes from a different constituent, ascaridole, rather than from boldine itself.

The Connexin Hemichannel Hypothesis

Connexins build two different structures. Docked in pairs between neighbouring cells they form gap junctions, the channels that let cells share ions and small metabolites. Undocked in a single membrane they form hemichannels, which are normally closed and open pathologically under inflammation, ischaemia and metabolic stress — leaking ATP, glutamate and Ca²⁺ into the extracellular space and amplifying whatever injury opened them.

Boldine inhibits the hemichannel and leaves the gap junction alone. In cultured astrocytes and microglia and in acute hippocampal slices it blocked hemichannel activity without affecting gap junctional communication, and long-term oral boldine in a mouse Alzheimer’s model prevented the rise in glial hemichannel activity, the astrocytic Ca²⁺ signal, and ATP and glutamate release, reducing hippocampal neuronal suffering ^{20Reference 20Yi C et al. · 2017AnimalInhibition of glial hemichannels by boldine treatment reduces neuronal suffering in a murine model of Alzheimer’s disease — animal in vivoView study →}.

The same mechanism has since been run against several unrelated injuries. Oral boldine reduced muscle atrophy and improved neuromuscular recovery after delayed nerve repair in rats ^{21Reference 21Burrell JC et al. · 2023AnimalOrally administered boldine reduces muscle atrophy and promotes neuromuscular recovery in a rodent model of delayed nerve repair — animal in vivoView study →}, and prevented the skeletal-muscle atrophy of experimental diabetes, which the same group attributed to non-selective channel opening ^{22Reference 22Cea LA et al. · 2023AnimalSkeletal muscle atrophy induced by diabetes is mediated by non-selective channels and prevented by boldine — animal in vivoView study →}. Reviewers of the field now argue that many, possibly all, of boldine’s effects in rodent models of injury and disease follow from hemichannel blockade rather than from its antioxidant chemistry ^{19Reference 19Sáez JC et al. · 2024ReviewPharmacology of boldine: summary of the field and update on recent advances — reviewView study →}.

That is a unifying interpretation, not a settled fact. It is attractive because it explains an otherwise incoherent list — liver, kidney, brain, muscle, vessel — with one target, and because hemichannel blockers are a small and genuinely novel pharmacological category. It is unproven in people: there is no human study of boldine at any endpoint, and the concentrations that block hemichannels in culture have not been shown to be reached in human tissue.

Boldine Is Not Ascaridole

Boldo has a fearsome safety reputation, and almost none of it belongs to boldine.

The leaf’s essential oil is 16–38% ascaridole, a peroxide monoterpene that is genuinely toxic; pharmacopoeial guidance is that boldo oil should never be taken internally ^{32Reference 32European Medicines Agency · 2016ReviewAssessment report on Peumus boldus Molina, folium — regulatory monographView study →}. Boldine is the water- and alcohol-extractable alkaloid — it is what an infusion gets you, and the volatile oil is what it does not. The two separate by extraction method, so a claim about one says nothing about the other. The documented human hepatotoxicity case linked to boldo involved a boldo-containing herbal laxative, i.e. a manufactured preparation, not isolated boldine ^{18Reference 18Piscaglia F et al. · 2005Case reportCaution in the use of boldo in herbal laxatives: a case of hepatotoxicity — case reportView study →}.

Run the two literatures side by side and the contrast is sharp: boldine is hepatoprotective in independent rodent models — against CCl₄ ^{8Reference 8Ezhilarasan D et al. · 2024AnimalBoldine protects against carbon tetrachloride-induced chronic liver injury by regulating NF-κB signaling pathway — animal in vivoView study →}, against 5-fluorouracil ^{5Reference 5Divya Dharshini K et al. · 2026AnimalBoldine activates Nrf2/ARE signaling to alleviate 5-fluorouracil-induced apoptosis, oxidative stress and inflammation in liver tissue of rats — animal in vivoView study →}, as a choleretic ^{7Reference 7Cermanova J et al. · 2015AnimalBoldine enhances bile production in rats via osmotic and farnesoid X receptor dependent mechanisms — animal in vivoView study →}, and in the classic Peumus boldus extract work ^{6Reference 6Lanhers MC et al. · 1991AnimalHepatoprotective and anti-inflammatory effects of a traditional medicinal plant of Chile, Peumus boldus — animal in vivoView study →} — while the boldo herb has been linked to reversible liver injury in case reports. The likeliest reconciliation is that they are different exposures.

Boldine has one safety flag genuinely its own, and it is not hepatic: a reproducible genotoxicity signal ^{16,17Reference 16Tavares DC · 1994In vitroEvaluation of the genotoxic potential of the alkaloid boldine in mammalian cell systems in vitro and in vivoView study →Reference 17Moreno PR et al. · 1991Genotoxicity of the boldine aporphine alkaloid in prokaryotic and eukaryotic organismsView study →}.

What It's Used For

The defining chemical property is potent chain-breaking radical scavenging ^{1Reference 1O’Brien P et al. · 2006ReviewBoldine and its antioxidant or health-promoting properties — reviewView study →}; the defining pharmacological one is hemichannel blockade ^{19Reference 19Sáez JC et al. · 2024ReviewPharmacology of boldine: summary of the field and update on recent advances — reviewView study →}. Everything below is preclinical. The human evidence for boldo’s traditional digestive use belongs to the leaf, not the isolated alkaloid.

Evidence by IndicationStrength of support · Beta

01Antioxidant / cytoprotectiveShaky44%Decades of direct radical-scavenging + Nrf2 data, plus an in-vivo atherosclerosis endpoint ^{1,2,3,5Reference 1O’Brien P et al. · 2006ReviewBoldine and its antioxidant or health-promoting properties — reviewView study →Reference 2Jiménez I et al. · 2000Protective effects of boldine against free radical-induced erythrocyte lysisView study →Reference 3Santanam N et al. · 2004AnimalA novel alkaloid antioxidant, boldine, and synthetic antioxidant, reduced form of RU486, inhibit the oxidation of LDL in-vitro and atherosclerosis in vivo in LDLR(-/-) mice — animal in vivoView study →Reference 5Divya Dharshini K et al. · 2026AnimalBoldine activates Nrf2/ARE signaling to alleviate 5-fluorouracil-induced apoptosis, oxidative stress and inflammation in liver tissue of rats — animal in vivoView study →}

02Hepatoprotective / cholereticShaky40%Traditional boldo use + animal choleresis/liver-protection ^{6,7,8Reference 6Lanhers MC et al. · 1991AnimalHepatoprotective and anti-inflammatory effects of a traditional medicinal plant of Chile, Peumus boldus — animal in vivoView study →Reference 7Cermanova J et al. · 2015AnimalBoldine enhances bile production in rats via osmotic and farnesoid X receptor dependent mechanisms — animal in vivoView study →Reference 8Ezhilarasan D et al. · 2024AnimalBoldine protects against carbon tetrachloride-induced chronic liver injury by regulating NF-κB signaling pathway — animal in vivoView study →}

03NeuroprotectiveShaky36%Oral dosing in mouse Alzheimer’s, epilepsy and cell models, with a named target ^{11,12,20Reference 11Toledo JP et al. · 2021In vitroBoldine attenuates synaptic failure and mitochondrial deregulation in cellular models of Alzheimer’s disease — in vitroView study →Reference 12Moezi L et al. · 2019AnimalAcute boldine treatment induces anti-convulsant effects in mice through its antioxidant activity — animal in vivoView study →Reference 20Yi C et al. · 2017AnimalInhibition of glial hemichannels by boldine treatment reduces neuronal suffering in a murine model of Alzheimer’s disease — animal in vivoView study →}

04Anti-inflammatoryShaky32%NF-κB/Nrf2 modulation in liver/kidney models ^{6,8Reference 6Lanhers MC et al. · 1991AnimalHepatoprotective and anti-inflammatory effects of a traditional medicinal plant of Chile, Peumus boldus — animal in vivoView study →Reference 8Ezhilarasan D et al. · 2024AnimalBoldine protects against carbon tetrachloride-induced chronic liver injury by regulating NF-κB signaling pathway — animal in vivoView study →}

05Muscle atrophy / neuromuscular recoveryShaky30%Two independent oral-dosing rodent models with a hemichannel readout ^{21,22Reference 21Burrell JC et al. · 2023AnimalOrally administered boldine reduces muscle atrophy and promotes neuromuscular recovery in a rodent model of delayed nerve repair — animal in vivoView study →Reference 22Cea LA et al. · 2023AnimalSkeletal muscle atrophy induced by diabetes is mediated by non-selective channels and prevented by boldine — animal in vivoView study →}

06Anti-diabetic / anti-fibroticShaky28%Renal TGF-β, gluconeogenesis, diabetic nephropathy ^{9,10,31Reference 9Gómez GI · 2018AnimalBoldine improves kidney damage in the Goldblatt 2K1C model avoiding the increase in TGF-β — animal in vivoView study →Reference 10Silva LCL et al. · 2023Inhibition of gluconeogenesis by boldine in the perfused liver: therapeutical implication for glycemic controlView study →Reference 31Hernández-Salinas R et al. · 2013AnimalBoldine prevents renal alterations in diabetic rats — animal in vivoView study →}

07Dopamine / adrenoceptor activityShaky22%Receptor-binding pharmacology (low native affinity) ^{13,14Reference 13Eltze M et al. · 2002In vitroAffinity profile at alpha(1)- and alpha(2)-adrenoceptor subtypes and in vitro cardiovascular actions of (+)-boldineView study →Reference 14Asencio M et al. · 1999AnimalBiochemical and behavioral effects of boldine and glaucine on dopamine systems — animal in vivoView study →}

Mechanisms

Pharmacokinetics

Boldine is lipophilic and orally absorbed, but the numbers are unflattering. In Lewis rats given 10 mg/kg, oral bioavailability was 7%, intravenous half-life 12 ± 4.6 minutes, and volume of distribution 3.2 L/kg — a compound that goes in easily, distributes widely and leaves fast ^{15Reference 15Cermanova J et al. · 2016AnimalPharmacokinetics of boldine in control and Mrp2-deficient rats — animalView study →}. Elimination is overwhelmingly metabolic: β-glucuronidase treatment of the samples showed conjugation accounts for at least 38% of total clearance, while biliary and renal routes together contributed less than 2% ^{15Reference 15Cermanova J et al. · 2016AnimalPharmacokinetics of boldine in control and Mrp2-deficient rats — animalView study →}. Mrp2-deficient rats cleared it more slowly, with a longer half-life and lower bioavailability still, confirming boldine and its conjugates as Mrp2 substrates and implying enterohepatic recycling ^{15Reference 15Cermanova J et al. · 2016AnimalPharmacokinetics of boldine in control and Mrp2-deficient rats — animalView study →}. Earlier disposition work reached the same conclusion — rapid, extensive phase-II conjugation ^{33Reference 33Jiménez I · 2000In vitroBiological disposition of boldine: in vitro and in vivo studies — animalView study →}.

The practical consequence: a short half-life and low oral exposure mean the rodent studies that work use repeated daily dosing, and in-vitro concentrations do not translate straightforwardly to systemic ones ^{30Reference 30Akotkar L et al. · 2023ReviewAn overview of chemistry, kinetics, toxicity and therapeutic potential of boldine in neurological disorders — reviewView study →}. Blood-brain-barrier penetration is not firmly quantified despite the CNS activity, and there is no human pharmacokinetics for the isolate at all — human exposure data are for boldo-leaf preparations.

Clinical trials

There are no trials of isolated boldine. The human evidence base is for the boldo herb, and consists of one placebo-controlled crossover in 12 healthy volunteers in which 2.5 g of dry boldo extract prolonged oro-caecal transit from 87 to 112 minutes ^{24Reference 24Gotteland M et al. · 1995RCTEffect of a dry boldo extract on oro-cecal intestinal transit in healthy volunteers — randomised, placebo-controlled crossover trialView study →} — a measurement of an effect, not of a benefit.

Last checked: September 2026.

Isolate vs. Plant Studies

Nearly all of it is the isolate. Every mechanism on this molecule — hemichannel blockade, Nrf2 activation, choleresis, adrenoceptor binding — was established with purified boldine in cells or in rodents dosed with the pure compound. That is normally a strength on a compound page. Here it is the weakness, because nothing bridges to a person: no human study of boldine at any dose or endpoint exists.

The plant side is thin and belongs to boldo. The hepatoprotective/anti-inflammatory work of Lanhers and colleagues used a Peumus boldus extract rather than the isolate ^{6Reference 6Lanhers MC et al. · 1991AnimalHepatoprotective and anti-inflammatory effects of a traditional medicinal plant of Chile, Peumus boldus — animal in vivoView study →}, and the only controlled human data are Gotteland’s 12-volunteer crossover of a dry boldo extract ^{24Reference 24Gotteland M et al. · 1995RCTEffect of a dry boldo extract on oro-cecal intestinal transit in healthy volunteers — randomised, placebo-controlled crossover trialView study →}. Neither apportions its effect to boldine, and boldine is not even the dominant alkaloid in the leaf those preparations are made from ^{25Reference 25Fuentes-Barros G et al. · 2018Variation of the alkaloid content of Peumus boldus (boldo)View study →}.

One study does connect the two directly, and it is worth the weight. In a pentylenetetrazole kindling model, mice fed pulverised boldo leaves showed reduced seizure severity comparable to valproate — but with the opposite effect on the mechanism: valproate increased glial dye uptake and glial reactivity, while boldo reduced both, exactly as a hemichannel blocker should ^{23Reference 23García-Rodríguez C et al. · 2025AnimalBoldo leaves reduce seizures, neuroinflammation, and hemichannel activity in a murine model of chronic epilepsy — animal in vivoView study →}. That is the whole plant reproducing the isolate’s signature, in the isolate’s own assay. It remains an animal study, and pulverised leaf carries the essential oil along with the alkaloids.

Its Role in Plants

Boldine is an aporphine, built from the benzylisoquinoline pathway that also yields coclaurine, reticuline and — in other families — morphine and berberine. The aporphine ring system is formed by oxidative phenol coupling of a benzylisoquinoline precursor, the same bond-forming step chemists imitate when they make boldine in the laboratory ^{29Reference 29Kupchan SM et al. · 1976Novel photochemical aporphine synthesis via spirodienone rearrangement: (±)-boldineView study →}.

Its ecological function looks like defence. Four benzylisoquinoline alkaloids isolated from Chilean trees — coclaurine, laurolitsine, boldine and pukateine — were insecticidal against the fruit fly Drosophila melanogaster and the codling moth Cydia pomonella, disrupting larval feeding and movement at 10 µg/mL and 50 µg/mL respectively, with docking implicating insect octopamine and ecdysone receptors ^{27Reference 27Quiroz-Carreño S et al. · 2020Assessment of insecticidal activity of benzylisoquinoline alkaloids from Chilean Rhamnaceae plants against fruit-fly Drosophila melanogaster and the lepidopteran crop pest Cydia pomonellaView study →}. Alkaloid content in boldo also varies strongly with tree age and sex and between individual trees, which is the pattern expected of an inducible defensive metabolite rather than a structural one ^{25Reference 25Fuentes-Barros G et al. · 2018Variation of the alkaloid content of Peumus boldus (boldo)View study →}.

Prevalence in Nature

Boldine is a Chilean-flora alkaloid above all, concentrated in the Monimiaceae and Lauraceae of the central Chilean sclerophyll forest, with scattered occurrences in the Papaveraceae.

Its distribution within boldo itself is the fact most often got wrong. A survey of eighteen alkaloids across the bark, leaves, wood and roots of Peumus boldus, with the leaf profile determined for 130 individually identified trees, found boldine dominant in the bark and laurolitsine dominant in wood and root — while the leaf was highly variable and usually led by N-methyllaurotetanine, laurotetanine and coclaurine, not by boldine ^{25Reference 25Fuentes-Barros G et al. · 2018Variation of the alkaloid content of Peumus boldus (boldo)View study →}. Quantitatively the leaf figure is small: an earlier study of northern, central and southern Chilean populations put boldine at 0.007–0.009% of dried leaf, with no significant difference between populations ^{26Reference 26Vogel H et al. · 1999Studies of genetic variation of essential oil and alkaloid content in boldo (Peumus boldus)View study →}. The alkaloid most people associate with boldo leaf is a minor component of it.

Beyond boldo, boldine has been isolated from Cryptocarya alba (peumo, Lauraceae) and Laurelia sempervirens (Chilean laurel, Monimiaceae), the two species usually worked up alongside boldo in Chilean alkaloid chemistry ^{28Reference 28Castro-Saavedra S et al. · 2026In vitroMolecular docking and experimental evaluation of natural alkaloids from Chilean flora (Cryptocarya alba, Peumus boldus, and Laurelia sempervirens) for tyrosinase inhibition and depigmenting potential — in vitroView study →}, and it occurs as a minor alkaloid of California poppy (Eschscholzia californica).

Major Natural Sources

Source	Part	Level	Note
Boldo (Peumus boldus)	bark	dominant alkaloid	the richest tissue, and the practical extraction feedstock 25Reference 25Fuentes-Barros G et al. · 2018Variation of the alkaloid content of Peumus boldus (boldo)View study →
Boldo (Peumus boldus)	leaf	0.007–0.009% dry wt	highly variable; usually not the leading leaf alkaloid 25,26Reference 25Fuentes-Barros G et al. · 2018Variation of the alkaloid content of Peumus boldus (boldo)View study →Reference 26Vogel H et al. · 1999Studies of genetic variation of essential oil and alkaloid content in boldo (Peumus boldus)View study →
Boldo (Peumus boldus)	wood, root	minor	laurolitsine dominates these tissues 25Reference 25Fuentes-Barros G et al. · 2018Variation of the alkaloid content of Peumus boldus (boldo)View study →
Peumo (Cryptocarya alba)	bark/leaf	not quantified	isolated for pharmacological screening 28Reference 28Castro-Saavedra S et al. · 2026In vitroMolecular docking and experimental evaluation of natural alkaloids from Chilean flora (Cryptocarya alba, Peumus boldus, and Laurelia sempervirens) for tyrosinase inhibition and depigmenting potential — in vitroView study →
Chilean laurel (Laurelia sempervirens)	bark/leaf	not quantified	isolated for pharmacological screening 28Reference 28Castro-Saavedra S et al. · 2026In vitroMolecular docking and experimental evaluation of natural alkaloids from Chilean flora (Cryptocarya alba, Peumus boldus, and Laurelia sempervirens) for tyrosinase inhibition and depigmenting potential — in vitroView study →
California poppy (Eschscholzia californica)	aerial parts	minor	one of several aporphines in the alkaloid fraction

Discovery & Synthesis

Boldine is named directly for the tree it came from, and was characterised from Peumus boldus in the nineteenth century as one of the first aporphine alkaloids described; a single first-isolation date and discoverer are not reliably established in the accessible record.

The chemistry is better documented. In 1976 Kupchan, Kim and Miyano prepared (±)-boldine by a photochemical route in which a spirodienone intermediate rearranges to the aporphine skeleton — a laboratory version of the oxidative phenol coupling the plant uses ^{29Reference 29Kupchan SM et al. · 1976Novel photochemical aporphine synthesis via spirodienone rearrangement: (±)-boldineView study →}. Aporphine total synthesis has continued to develop since, most recently through photocatalytic oxidative phenol coupling.

Boldine is not made synthetically for supply. It is extracted from boldo, and the bark rather than the leaf is the rational feedstock ^{25Reference 25Fuentes-Barros G et al. · 2018Variation of the alkaloid content of Peumus boldus (boldo)View study →} — the leaf that the herbal trade sells is the alkaloid-poorer tissue. Isolated boldine is then the starting material for semisynthesis: diacetylboldine and 3-bromoboldine are both made from it ^{28Reference 28Castro-Saavedra S et al. · 2026In vitroMolecular docking and experimental evaluation of natural alkaloids from Chilean flora (Cryptocarya alba, Peumus boldus, and Laurelia sempervirens) for tyrosinase inhibition and depigmenting potential — in vitroView study →}, and it is also the standard precursor for N-methyllaurotetanine, which is boldine methylated at C-2.

Patents: not yet researched (future patent-loop pass).

Diacetylboldine, the Cosmetic Derivative

The one commercial product derived from boldine is not a medicine. Diacetylboldine, sold as Lumiskin, is a skin-lightening cosmetic ingredient, and the rationale is tyrosinase inhibition — tyrosinase being the rate-limiting enzyme of melanin synthesis.

The best controlled test of that rationale is unkind to it. Against mushroom tyrosinase, boldine itself was weak (IC₅₀ 6.56 mM, against kojic acid’s 0.014 mM), and diacetylboldine (2.22 mM) and 3-bromoboldine (1.96 mM) were both better than the parent but still far from a reference standard. In a three-dimensional reconstructed epidermis model dosed topically at 0.1% for 14 days, 3-bromoboldine reduced melanin by 33% — comparable to arbutin — while boldine managed 10% and diacetylboldine was inactive ^{28Reference 28Castro-Saavedra S et al. · 2026In vitroMolecular docking and experimental evaluation of natural alkaloids from Chilean flora (Cryptocarya alba, Peumus boldus, and Laurelia sempervirens) for tyrosinase inhibition and depigmenting potential — in vitroView study →}. The marketed derivative was the one that did nothing; the halogenated analogue that worked is not the one on sale.

Toxicity & Safety

The severe things people have heard about boldo mostly belong to its ascaridole-rich essential oil, not to boldine — but boldine has one flag of its own, a reproducible genotoxicity signal, and no human safety data to weigh it against.

Safety at a Glance

⚠️ Moderate toxicityLiver risk

• Reproducible genotoxicity signal. Reported mutagenic activity in prokaryotic and mammalian test systems — the genuine isolate-level flag.
• Contraindicated in pregnancy and breastfeeding.
• Boldo’s hepatotoxicity is chiefly its essential oil. The ascaridole-rich oil, not boldine, drives the severe liver reports — a documented human case involved a boldo-containing laxative.
• Benefit is not monotonic. Boldine flips pro-oxidant at higher concentrations, so more is not better.
• No human safety data for purified boldine. Human exposure data are all for the leaf preparation.

Full Safety & Interactions Detail

Isolated boldine has low-to-moderate acute toxicity and is not the driver of boldo’s worst safety signals. Boldo’s hepatotoxicity and abortifacient reputation is largely its essential oil, high in ascaridole — a neurotoxic and hepatotoxic terpene endoperoxide making up 16–38% of the volatile oil, which pharmacopoeias say should never be taken internally ^{32Reference 32European Medicines Agency · 2016ReviewAssessment report on Peumus boldus Molina, folium — regulatory monographView study →}; the documented human hepatotoxicity case involved a boldo-containing laxative, i.e. herb/oil exposure ^{18Reference 18Piscaglia F et al. · 2005Case reportCaution in the use of boldo in herbal laxatives: a case of hepatotoxicity — case reportView study →}.

The genuine isolate-level flag is genotoxicity: boldine has reported genotoxic and mutagenic activity in prokaryotic and mammalian test systems ^{16,17Reference 16Tavares DC · 1994In vitroEvaluation of the genotoxic potential of the alkaloid boldine in mammalian cell systems in vitro and in vivoView study →Reference 17Moreno PR et al. · 1991Genotoxicity of the boldine aporphine alkaloid in prokaryotic and eukaryotic organismsView study →}, although it is also widely studied as an antigenotoxic antioxidant — a real pro-oxidant duality, with benefit that is not monotonic, since higher concentrations can generate rather than quench radicals ^{4Reference 4Konrath EL et al. · 2008In vitroAntioxidant and pro-oxidant properties of boldine on hippocampal slices exposed to oxygen-glucose deprivation in vitroView study →}.

No human safety data exist for purified boldine.

Interactions have not been assessed. No CYP or transporter interaction study of boldine in humans exists. What is known is that boldine and its conjugates are substrates of the Mrp2 efflux transporter, and that at least 38% of its clearance is phase-II conjugation ^{15Reference 15Cermanova J et al. · 2016AnimalPharmacokinetics of boldine in control and Mrp2-deficient rats — animalView study →} — so competition at glucuronidation or at Mrp2 is the plausible route, and it is untested. This combination — reproducible genotoxicity, a pro-oxidant ceiling, an unassessed interaction profile and the inherited pregnancy contraindication — is why boldine is flagged moderate rather than low. The severe boldo liver events belong to ascaridole, not here.

Dosage

There is no established human dose for isolated boldine, and nothing here is a recommendation.

The rodent figures do not convert to human guidance, and the short half-life and 7% oral bioavailability measured in rats ^{15Reference 15Cermanova J et al. · 2016AnimalPharmacokinetics of boldine in control and Mrp2-deficient rats — animalView study →} are part of why: the doses that work in animals are repeated daily doses, not single ones. Benefit is also non-monotonic — boldine has a pro-oxidant ceiling ^{4Reference 4Konrath EL et al. · 2008In vitroAntioxidant and pro-oxidant properties of boldine on hippocampal slices exposed to oxygen-glucose deprivation in vitroView study →}. For the herb, standardised boldo-leaf products taken short-term are the studied form, and boldo essential oil is not for internal use. These are doses studied in research and are not a personal recommendation.

References

1. O’Brien P, Carrasco-Pozo C, Speisky H (2006). Boldine and its antioxidant or health-promoting properties — review. Chemico-Biological Interactions. https://pubmed.ncbi.nlm.nih.gov/16221469/
2. Jiménez I, Garrido A, Bannach R, et al. (2000). Protective effects of boldine against free radical-induced erythrocyte lysis. Phytotherapy Research. https://pubmed.ncbi.nlm.nih.gov/10925398/
3. Santanam N, Penumetcha M, Speisky H, et al. (2004). A novel alkaloid antioxidant, boldine, and synthetic antioxidant, reduced form of RU486, inhibit the oxidation of LDL in-vitro and atherosclerosis in vivo in LDLR(-/-) mice — animal in vivo. Atherosclerosis. https://pubmed.ncbi.nlm.nih.gov/15064093/
4. Konrath EL, Santin K, Nassif M, et al. (2008). Antioxidant and pro-oxidant properties of boldine on hippocampal slices exposed to oxygen-glucose deprivation in vitro. Neurotoxicology. https://pubmed.ncbi.nlm.nih.gov/18590764/
5. Divya Dharshini K, Sharmila M, Munusamy K, et al. (2026). Boldine activates Nrf2/ARE signaling to alleviate 5-fluorouracil-induced apoptosis, oxidative stress and inflammation in liver tissue of rats — animal in vivo. Drug and Chemical Toxicology. https://pubmed.ncbi.nlm.nih.gov/41906215/
6. Lanhers MC, Joyeux M, Soulimani R, et al. (1991). Hepatoprotective and anti-inflammatory effects of a traditional medicinal plant of Chile, Peumus boldus — animal in vivo. Planta Medica. https://pubmed.ncbi.nlm.nih.gov/1891491/
7. Cermanova J, Kadova Z, Zagorova M, et al. (2015). Boldine enhances bile production in rats via osmotic and farnesoid X receptor dependent mechanisms — animal in vivo. Toxicology and Applied Pharmacology. https://pubmed.ncbi.nlm.nih.gov/25771127/
8. Ezhilarasan D, Shree Harini K, Karthick M, et al. (2024). Boldine protects against carbon tetrachloride-induced chronic liver injury by regulating NF-κB signaling pathway — animal in vivo. Journal of Biochemical and Molecular Toxicology. https://pubmed.ncbi.nlm.nih.gov/38500399/
9. Gómez GI, Velarde V (2018). Boldine improves kidney damage in the Goldblatt 2K1C model avoiding the increase in TGF-β — animal in vivo. International Journal of Molecular Sciences. https://pubmed.ncbi.nlm.nih.gov/29941815/
10. Silva LCL, de Souza GH, Pateis VO, et al. (2023). Inhibition of gluconeogenesis by boldine in the perfused liver: therapeutical implication for glycemic control. International Journal of Hepatology. https://pubmed.ncbi.nlm.nih.gov/37056327/
11. Toledo JP, Fernández-Pérez EJ, Ferreira IL, et al. (2021). Boldine attenuates synaptic failure and mitochondrial deregulation in cellular models of Alzheimer’s disease — in vitro. Frontiers in Neuroscience. https://pubmed.ncbi.nlm.nih.gov/33679301/
12. Moezi L, Yahosseini S, Jamshizadeh A, et al. (2019). Acute boldine treatment induces anti-convulsant effects in mice through its antioxidant activity — animal in vivo. Drug Research. https://pubmed.ncbi.nlm.nih.gov/30081409/
13. Eltze M, Grebe T, Michel MC, et al. (2002). Affinity profile at alpha(1)- and alpha(2)-adrenoceptor subtypes and in vitro cardiovascular actions of (+)-boldine. European Journal of Pharmacology. https://pubmed.ncbi.nlm.nih.gov/12044805/
14. Asencio M, Delaquerrière B, Cassels BK, et al. (1999). Biochemical and behavioral effects of boldine and glaucine on dopamine systems — animal in vivo. Pharmacology, Biochemistry and Behavior. https://pubmed.ncbi.nlm.nih.gov/9972839/
15. Cermanova J, Prasnicka A, Dolezelova E, et al. (2016). Pharmacokinetics of boldine in control and Mrp2-deficient rats — animal. Physiological Research. https://pubmed.ncbi.nlm.nih.gov/28006931/
16. Tavares DC, Takahashi CS (1994). Evaluation of the genotoxic potential of the alkaloid boldine in mammalian cell systems in vitro and in vivo. Mutation Research. https://pubmed.ncbi.nlm.nih.gov/7513064/
17. Moreno PR, Vargas VM, Andrade HH, et al. (1991). Genotoxicity of the boldine aporphine alkaloid in prokaryotic and eukaryotic organisms. Mutation Research. https://pubmed.ncbi.nlm.nih.gov/2046695/
18. Piscaglia F, Leoni S, Venturi A, et al. (2005). Caution in the use of boldo in herbal laxatives: a case of hepatotoxicity — case report. Scandinavian Journal of Gastroenterology. https://pubmed.ncbi.nlm.nih.gov/15764158/
19. Sáez JC, Burrell JC, Cahill CM, et al. (2024). Pharmacology of boldine: summary of the field and update on recent advances — review. Frontiers in Pharmacology. https://pubmed.ncbi.nlm.nih.gov/39346563/
20. Yi C, Ezan P, Fernández P, et al. (2017). Inhibition of glial hemichannels by boldine treatment reduces neuronal suffering in a murine model of Alzheimer’s disease — animal in vivo. Glia. https://pubmed.ncbi.nlm.nih.gov/28703353/
21. Burrell JC, Vu PT, Alcott OJB, et al. (2023). Orally administered boldine reduces muscle atrophy and promotes neuromuscular recovery in a rodent model of delayed nerve repair — animal in vivo. Frontiers in Cellular Neuroscience. https://pubmed.ncbi.nlm.nih.gov/37829672/
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