Mucuna pruriens is a tropical legume known as velvet bean, cowitch or cowhage. The seeds of Mucuna pruriens have been traditionally used for treating male sexual dysfunction and for the treatment of degenerative disorders such as Parkinson’s Disease.
Mucuna pruriens supplementation has been shown to increase circulating dopamine levels in healthy male controls, possibly through the main ingredient of L-DOPA (levodopa). L-DOPA is a naturally occurring non-protein amino acid, synthesized from L-tyrosine. The most important function of L-DOPA is to act as the precursor to the neurotransmitter dopamine, as well as the catecholamines epinephrine and norepinephrine The plant also contains serotonin ( 5-HTP ), which is known to regulate aging, learning and memory . Serotonin has also been linked to fatigue because of its well-known effects on sleep, lethargy and drowsiness, and loss of motivation. 
L-DOPA containing Mucuna pruriens may also elevate human growth hormone as results of study, in 8 normal subjects and in 7 patients with Parkinson’s disease, confirmed increased growth hormone release 60–110 min following a single oral dose of 500 mg of L-DOPA . Boyd, A. E.  also confirmed that L-DOPA therapy, appears to elevate plasma growth hormone. Mucuna pruriens extract seems to be superior to synthetic L-DOPA, at least in in ameliorating Parkinson’s complications . In combination with Chlorophytum borivilianum, Mucuna pruriens has been show to increase circulating growth hormone in exercise-trained men . However, this study did not include control group and was funded by UPSlabs.
Effects on Testosterone Concentrations
In a study conducted by Shukla KK. and colleagues , Mucuna pruriens supplementation significantly improved testosterone, luteinizing hormone, dopamine, adrenaline, and noradrenaline levels in infertile men and reduced levels of FSH and PRL. Sperm count and semen quality were significantly improved in infertile men after treatment. Probably individuals respond differently to it, be cause study by Sinhamahapatra, S. B. et al.  noted no significant alterations in plasma testosterone levels.
Mucuna pruriens is nowadays used in many testosterone boosters. However, it is not know if its supplementation can increase testosterone levels in fertile healthy men but it sure does have the potential.
Mucuna Pruriens Side Effects
Mucuna pruriens should be taken cautiously in people with cardiovascular disease, due to its levodopa (L-DOPA) content. L-DOPA may also decrease blood pressure. One of the most common side effects is a sensation of abdominal bloating. 
- Shukla KK, et al. Mucuna pruirens improves male fertility by its action on the hypothalamus-pituitary-gonadal axis. Fertil Steril. (2009)
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