Griffonia Simplicifolia - Sinemet (Carbidopa, Levodopa) Interaction
Herbal: Griffonia Simplicifolia
Also Known As: Bandeiraea simplicifolia
Drug: Carbidopa, Levodopa
Brand names:
Sinemet CR, Sinemet, Rytary, Dhivy

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 11, 2025
Interaction Details
Carbidopa, Levodopa is classified as belonging to the following category: Carbidopa (Lodosyn)
Theoretically, taking Griffonia simplicifolia seed extract with carbidopa might increase the risk of serotonergic and other adverse effects.
Griffonia simplicifolia seed extract contains 5-HTP. Taking 5-HTP with carbidopa increases the risk of serotonergic adverse effects, scleroderma-like skin reactions, hypomania, restlessness, rapid speech, anxiety, insomnia, and aggressiveness.
Interaction Rating
Likelihood of Occurrence
PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
References
- Sternberg EM, Van Woert MH, Young SN, et al. Development of a scleroderma-like illness during therapy with L-5-hydroxytryptophan and carbidopa. N Engl J Med 1980;303:782-7.
- Iovieno, N., Dalton, E. D., Fava, M., and Mischoulon, D. Second-tier natural antidepressants: review and critique. J Affect.Disord. 2011;130(3):343-357.
- van Hiele LJ. l-5-Hydroxytryptophan in depression: the first substitution therapy in psychiatry? The treatment of 99 out-patients with 'therapy-resistant' depressions. Neuropsychobiology 1980;6:230-40.
- Lemaire PA, Adosraku RK. An HPLC method for the direct assay of the serotonin precursor, 5-hydroxytrophan, in seeds of Griffonia simplicifolia. Phytochem Anal 2002;13(6):333-7.
Griffonia Simplicifolia Overview

Carbidopa, Levodopa Overview
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The combination of levodopa and carbidopa is used to treat the symptoms of Parkinson's disease and Parkinson's-like symptoms that may develop after encephalitis (swelling of the brain) or injury to the nervous system caused by carbon monoxide poisoning or manganese poisoning. Parkinson's symptoms, including tremors (shaking), stiffness, and slowness of movement, are caused by a lack of dopamine, a natural substance usually found in the brain. Levodopa is in a class of medications called central nervous system agents. It works by being converted to dopamine in the brain. Carbidopa is in a class of medications called decarboxylase inhibitors. It works by preventing levodopa from being broken down before it reaches the brain. This allows for a lower dose of levodopa, which causes less nausea and vomiting.
Griffonia Simplicifolia - More Interactions
Griffonia Simplicifolia interacts with 315 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
Unknown | No interactions have been reported or no interaction data is currently available. |
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Parts of this content are provided by the Therapeutic Research Center, LLC.
DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
© 2021 Therapeutic Research Center, LLC
Drug descriptions are provided by MedlinePlus.