EDIT March 17, 2024: Today somebody shared a link to a two year old post of mine about a report on Berberine being neurotoxic and taking it off of my stack.
Within a few months I found other information on Berberine and, using my High School educated brain, decided that Berberine definitely needed to stay on my stack and I even increased to 1200 mg a day. I have been taking 1200 mg a day (800 in the morning, 400 at night) ever since.
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Original Post:
Update 6/29/22: Berberine may be neurotoxic. It is off of my stack: healthunlocked.com/cure-par...
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I know it has only been a month since I posted on Berberine, healthunlocked.com/cure-par... , but I saw another study that was not mentioned and the title grabbed me: Oral berberine improves brain dopa/dopamine levels to ameliorate Parkinson’s disease by regulating gut microbiota nature.com/articles/s41392-...
They gave mice 100, 200 mg/kg orally and it affected the microbiome and increased dopamine in the intestines and in the brain. If I divide the 200 mg dose by 12 (for mice) and multiply it by 70 kg I get a dose of about 1200 mg for me.
They tested on humans too (500 mg twice a day):
" As shown in Table 1, after 8 weeks of BBR therapy, blood dopa/dopamine was elevated (dopa, NS, +17%↑; dopamine, *P < 0.05, +24%↑). Fecal tests demonstrated results similar to those of blood, showing an increase in dopa and dopamine in feces (dopa, ***P < 0.001, +46%↑; dopamine, ***P < 0.001, +47%↑, Table 1). Meanwhile, TH and DDC in gut microbiota were upregulated by BBR (TH, **P < 0.001, +42%↑; DDC, NS, +20%↑, Table 1). The results agreed with those detected in the animal experiments. Analysis of the microbial diversity in the fecal samples of 28 clinical patients showed that, after 2 months of BBR treatment, the relative abundance of Enterococcus increased by 11% (Fig. 5g; Table 1), in which E. faecalis and E. faecium were predominant.46 The results further validated that Enterococcus might be an interesting genus for dopa/dopamine biosynthesis in the intestine, and BBR might promote the body dopa/dopamine levels through the bacteria in intestine."
"Conclusion
This study discovered first that the gut microbiota is a new source of dopa/dopamine in the body, and second, BBR enhanced TH to produce l-dopa by triggering the biosynthesis of BH4 in the gut microbiota. As BBR has been an OTC drug for many years, it might have immediately applicable potential in regulating gut–brain dialog and improving brain function in humans."
Looks like I should push my dose from 800 mg to 1200 mg. 400 mg 3 times a day.