Massularia Acuminata (MA) is an aphrodisiac herb from Yoruba medicine of Nigeria.
The plant appears to contain a mixture of alkaloids, anthraquinones, saponins, phenolics, flavonoids, and tannins. The active ingredient is not known.
In several replicated rat studies, Massularia Acuminata (MA) has been shown to increase parameters of sexuality in males. It did increase testosterone, but did so at a level corresponding with sexual activity and lesser than the control (Viagra); these increases may be vicarious of increased sexual activity rather than from the compound itself.
Lower doses seem more effective than higher, with 50mg/kg bodyweight increasing sexuality and testosterone more than 100mg/kg and 200mg/kg. Although this relationship appears to be reversed at dosages of 500mg/kg and 1000mg/kg bodyweight, in which sexuality and testosterone levels begin to become elevated again. The 1000mg/kg group had a spike above the expected value, and was nearly double the control. These studies were conducted in otherwise healthy rats.
When 1000mg/kg in rats is converted into a human dosage based on Body Surface Area it results in a 160mg/kg bodyweight dosage of Massularia Accuminata; the lower dose, 50mg/kg, correlates to 8mg/kg bodyweight and is more feasible.
A U-shaped curve exists in animals, with 50mg/kg and 1000mg/kg both being effective but does between them to a lesser degree; as toxicity is associated with doses of 250mg/kg or above in animals, the lower dose may be prudent at this point in time
One rat study specifically investigating liver indices after water-soluble Massularia intake at 250mg/kg, 500mg/kg, and 1000mg/kg  noted decreases in activity of Alkaline Phosphatase (a liver enzyme) and increased serum levels of Alkaline Phosphatase at all doses starting on the first oral dose, with similar effects in the 250mg/kg and 500mg/kg group with slightly more suppression in the 1000mg/kg group. Similar increases in serum levels were seen with Aspartate aminotransferase and Alanine Aminotransferase although their activities in the liver increased (in contrast to Alkaline Phosphatase); increases in serum bilirubin were seen at all doses and not dose-dependent and increases in albumin were seen at 500mg/kg and 1000mg/kg.
The effects on day 21, relative to day 1, were trending to worsen but not statistically significant.
Evidence suggests that it may have hepatotoxic effects