Fadogia agrestis is a small shrub that grows in the savannah of West and Central Africa, including Nigeria. Botanists now also list it as Vangueria agrestis. The stem is the part used, usually as a dried powder or a concentrated extract such as a 10:1 ratio.
In Nigerian folk practice the stem has been traditionally used to support male vitality. Its reputation in modern supplements comes almost entirely from a few rat studies by one research group, which used an aqueous stem extract. There are no published human clinical trials, so nobody knows how it behaves in people, at what amount, or for how long.
The same rat research also raised safety signals. A 28-day study reported changes in testicular function markers at every dose tested, and a later study described effects on liver and kidney cells. These are animal findings and may not apply to people, but they are the main reason to approach fadogia with caution. In 2025 a European Commission consultation concluded that a fadogia extract is a novel food in the EU.