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Mucuna pruriens and motivation: grade D

Preliminary evidence. Direction: No effect.

D Preliminary

Why this grade

Rubric condition met: No controlled human motivation outcome data

Some products are labeled as supporting dopamine production and motivation, but as of November 11, 2026 we found no controlled human study of Mucuna that measured motivation (PubMed and Europe PMC searches, 2026-11-11). The levodopa content is a mechanism, not evidence of an effect on motivation.

How we grade evidence

Studies this grade rests on

Levodopa Content of Mucuna pruriens Supplements in the NIH Dietary Supplement Label Database.

Cohen PA, Avula B, Katragunta K. Levodopa Content of Mucuna pruriens Supplements in the NIH Dietary Supplement Label Database JAMA Neurol, 2022. PMID 35939305

Result not recorded
Design
Laboratory analysis of 16 dietary supplement products (case series)
Population
US Mucuna pruriens dietary supplements listed in the NIH Dietary Supplement Label Database
Funding
not stated in the published letter; COI statement lists grants to one author from The Pew Charitable Trusts and Consumers Union outside the submitted work

Search and history

Search (): (mucuna[tiab] OR "velvet bean"[tiab]) AND (depress*[tiab] OR mood[tiab] OR motivation[tiab] OR anhedonia[tiab]) AND (trial[tiab] OR randomized[tiab] OR placebo[tiab])

  • Graded D (proposed): Proposed in the monograph draft
  • D to D (approved): Editor sign-off November 13, 2026: grade matches the editor-approved final page