9-Me-BC (9-Methyl-β-carboline)

What 9-Me-BC is

9-Me-BC stands for 9-methyl-β-carboline, chemically 9-methyl-9H-pyrido[3,4-b]indole, also called 9-methylnorharmane. β-Carbolines occur in fruit, meat, coffee, alcohol and tobacco smoke; some are also found in human blood and brain. Many are considered possible neurotoxins, which is why the stimulating effect of 9-Me-BC on dopamine neurons surprised the researchers themselves.

The work comes from a closely connected circle of authors who proposed 9-Me-BC as a new Parkinson’s drug. The substance has not made its way into a clinical trial. Today it is sold as a research chemical.

How it is supposed to work

In cell cultures from the midbrain, 9-Me-BC increased the production of tyrosine hydroxylase, the key enzyme of dopamine synthesis, and several associated transcription factors. It promoted the outgrowth of nerve processes, protected against toxins, allowed dopamine neurons to re-emerge after rotenone damage, slowed the proliferation of microglia and lowered the protein alpha-synuclein. In astrocytes it stimulated genes for growth factors such as BDNF, mediated via the PI3K signaling pathway.

In addition, there is an inhibition of monoamine oxidase, the enzymes that break down dopamine, serotonin and noradrenaline: the half-maximal inhibitory concentration was 1 µM for MAO-A and 15.5 µM for MAO-B. The authors consider this inhibition a possible reason for the higher dopamine levels in their experiments.

What the studies show

Polanski 2010 – cell culture: stimulation, protection, regeneration

In primary cultures from the midbrain, 9-Me-BC increased tyrosine hydroxylase in existing neurons and the outgrowth of their processes. It protected against lipopolysaccharide and a carbolinium toxin, allowed dopamine neurons to re-emerge after chronic rotenone exposure, inhibited the proliferation of microglia, and lowered inflammatory messengers and the content of alpha-synuclein.

Wernicke 2010 – Parkinson’s model in the rat

Rats were pretreated for 28 days with the neurotoxin MPP+, which roughly halved the dopamine level. They then received 9-Me-BC directly into a brain ventricle for 14 days. Dopamine in the striatum and the number of dopamine neurons in the substantia nigra returned to normal values, and the activity of complex I of the respiratory chain was about 80 percent higher. Administration into the brain says nothing about the effect of a capsule.

Gruss 2012 – learning in rats

After ten days of treatment, not after five, rats learned better in the radial arm maze. In the hippocampus the dopamine level rose, and the nerve cells in the dentate gyrus had longer, more branched dendrites and more dendritic spines.

Keller 2020 – astrocytes and monoamine oxidase

9-Me-BC was not toxic in astrocyte cultures, inhibited their proliferation and increased the gene expression of growth factors for dopamine neurons, including BDNF. Uptake occurred partly via organic cation transporters. In the enzyme assay it inhibited MAO-A by half at 1 µM and MAO-B at 15.5 µM.

Vignoni 2013 – DNA damage under UV-A light

Three 9-methyl-β-carbolines, including 9-methylnorharmane, that is 9-Me-BC, were studied in the test tube with DNA and UV-A light. All of them damaged the DNA, mainly through oxidized purine bases, plus strand breaks and pyrimidine dimers. The authors describe the 9-methyl derivatives as particularly effective photosensitizers. Whether this happens in a person’s skin after intake has not been studied.

Where the data stop

There is not a single study in humans: no pharmacokinetics, no tolerability study, no efficacy study. A query of ClinicalTrials.gov on October 7, 2026 returned no entry for 9-methyl-β-carboline. It is therefore open whether the substance reaches the brain in a meaningful amount after swallowing, how long it stays there and what it does there.

The animal data are thin: few studies, small groups, overwhelmingly from the same circle of authors, and in the Parkinson’s model with administration directly into the brain. Inferring motivation or learning performance in humans from cell culture and rats skips every intermediate step.

Status, approval and legal

9-Me-BC is not approved as a medicine anywhere and has never been tested in a clinical trial. In Germany it is neither an approved medicine nor an approved food; it is not listed in the schedules of the German Narcotics Act, and the substance groups in the annex of the German New Psychoactive Substances Act (NpSG) do not explicitly describe β-carbolines.

It is traded as a research chemical. Market surveillance by official medicines control laboratories from Europe and Australia listed 9-Me-BC between 2020 and 2024 among the seized, unapproved nootropics as a research chemical (Vanhee 2025). The purity and content of such products are not controlled.

Safety

There are no safety data in humans. Three points from the lab are known. First, photosensitivity: 9-methyl-β-carbolines damaged DNA under UV-A light in the test tube. Second, MAO inhibition: whether this leads to interactions in humans, for example with antidepressants or stimulants, has not been studied.

Third, the relationship to a neurotoxin: when β-carbolines are methylated at both nitrogen atoms, 2,9-dimethyl-β-carbolinium is formed, which occurs in the brain, inhibits the respiratory chain similarly to MPP+ and damaged dopamine neurons in rats (Pavlovic 2006). 9-Me-BC already carries one of these two methyl groups. Whether it is converted to the carbolinium in the human body has not been studied; in cell culture, 9-Me-BC even protected against this toxin.

Sources

• Polanski W et al., J Neurochem 2010 – stimulation, protection and regeneration of dopaminergic neurons in cell culture (PMID 20374418)
• Wernicke C et al., Pharmacol Rep 2010 – restoration in a rat model of Parkinson’s disease (PMID 20360614)
• Gruss M et al., J Neurochem 2012 – better learning and more dopamine in the rat hippocampus (PMID 22380576)
• Keller S et al., J Neural Transm 2020 – MAO inhibition and growth factors in astrocytes (PMID 32285253)
• Vignoni M et al., Org Biomol Chem 2013 – DNA damage from photoexcited 9-methyl-β-carbolines (PMID 23842892)
• Pavlovic S et al., Neuroscience 2006 – 2,9-dimethyl-β-carbolinium as a neurotoxin (PMID 16517085)
• Vanhee C et al., J Xenobiot 2025 – market surveillance of unapproved nootropics by official control laboratories (PMID 40558871)
• ClinicalTrials.gov – search for 9-methyl-beta-carboline (no entry, queried October 7, 2026)