".... the highest concentrations of dopamine of any known natural substances." I think you correct this implicitly but M. pruriens contains l-dopa, not dopamine. Anything that produces a steady slow release of l-dopa will extend the effectiveness of a given dose of l-dopa and reduce or eliminate the side effect (dyskinesia). I don't know the answer to your question but one possibility is that the l-dopa is present as (one component of) a polypeptide that is slowly hydrolysed in the gut, releasing the l-dopa slowly. It is most likely to be present in a compound of some sort, whose degradation slowly releases free l-dopa. It has nothing to do with the bio-availability of dopamine. It might be improved if you added carbidopa to the M.pruriens extract because its function is to inhibit the conversion of l-dopa to dopamine in the body, preserving it for the brain.

From what I read, however, there are concerns about the safety of these plant extracts and they are banned in some countries.

Thank you for the correction re l-dopa, the ingested substance vs dopamine, the neurotransmitter.

Initial reviews of mucuna dismissed its benefits as impossible because in theory the ingested l-dopa would be broken down before it could cross the blood-brain barrier. This study gave functional (rather than biochemical) evidence to the contrary. With thousands of years of use of an herbal medicine by large populations, we might postulate some benefit. Safety is not what I read as a problem--where did you see this? I saw questions about quality production, standardization of l-dopa constituents and efficacy as the big issues.

In a study on levodopa content of fava beans, carbidopa was also detected. It appears to indicate the C-dopa cofactor is naturally occurring. Perhaps also in mucuna?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3708185/

“Fava bean consumption has been shown to increase the levels of L-dopa in the blood, with a marked improvement in the motor performance of the patients (‘ON’ period), without any side effects [8–10]....the other products which are derived from fava beans, which probably complement the anti-Parkinsonian effect, and, therefore, L-dopa, in the natural fava bean background, was observed to show positive clinical benefits.”

The sprouted beans were more digestible and seemingly still have a beneficial L-dopa and C-dopa profile. Although, I don’t quite understand the chemistry and extraction process they’re describing

“With respect to the [Table/Fig-2] you can see the amount of L-dopa and C-dopa in fava bean at condition of fresh and dry (L-dopa,1.43-1.51 mg/ml and C-dopa, 2.67–2.47 mg/ml).”