Fadogia agrestis is a shrub native to Africa, belonging to the same plant family as coffee (Rubiaceae). It has gained popularity as a testosterone-boosting supplement in the fitness and bodybuilding world, largely based on a small number of animal studies and endorsements from popular podcasters. The plant’s stem is the part used in supplements, and it is sold in the U.S. as a dietary supplement with no FDA approval for any medical use.
Where It Comes From
Fadogia agrestis grows across several regions of Africa, where it has a long history in traditional medicine. The stems, leaves, and roots have all been used in folk remedies, but the stem extract is what you’ll find in supplement capsules sold online and in health stores. Phytochemical analysis of the stem has identified alkaloids and saponins as its primary active compounds, with smaller amounts of anthraquinones and flavonoids.
Why People Take It
The supplement’s reputation rests almost entirely on a single line of rat studies conducted at a Nigerian university. When researchers gave male rats an aqueous extract of Fadogia agrestis stem, the animals showed significant increases in testosterone, luteinizing hormone, and follicle-stimulating hormone compared to controls. The rats also had increases in testicular weight relative to body weight and higher levels of testicular protein, glycogen, and cholesterol, all markers associated with reproductive activity.
These results sound compelling in isolation, and they’re the reason Fadogia agrestis is marketed for boosting testosterone, improving erectile function, and enhancing muscle growth. The problem is that rat hormone systems don’t map neatly onto human biology. There are zero published human clinical trials on Fadogia agrestis. None. Every claim you see about its effects in humans is extrapolated from rodent data or based on anecdotal reports.
Dosages on the Market
Traditional use of the plant involved doses in the range of 100 to 400 mg daily. Supplements sold online, however, often contain far higher amounts, typically between 1,000 and 1,600 mg per capsule serving. These products are marketed for increasing testosterone, alleviating “low T” symptoms, and supporting bodybuilding goals. The jump from traditional doses to supplement doses is significant, and no human study has established what a safe or effective dose looks like.
Safety Concerns
The same animal research that showed hormonal effects also raised red flags about organ toxicity. In a study examining how the extract affects liver and kidney cells in male rats, researchers found that Fadogia agrestis significantly reduced the activity of several important enzymes in the liver and kidney, including alkaline phosphatase, lactate dehydrogenase, and gamma glutamyl transferase. At the same time, levels of those enzymes rose in the blood. This pattern is a classic sign that cells in those organs are being damaged and leaking their contents into the bloodstream.
The study also found significant increases in serum malondialdehyde across all treated groups. Malondialdehyde is a byproduct of oxidative stress, meaning the extract was causing cellular damage through the same mechanism involved in aging and chronic disease. These findings appeared at the same doses that produced the testosterone increases, which means the potential benefits and the potential harms arrived together.
Because no human trials exist, it’s unknown whether these toxic effects translate to people, at what dose they might appear, or whether long-term use compounds the risk.
Regulatory Status
Fadogia agrestis is sold in the U.S. as a dietary supplement, which means it does not require FDA approval before going to market. The FDA has not evaluated it for safety or effectiveness for any health condition. It has no approved pharmaceutical use in any major regulatory jurisdiction. Manufacturers can legally sell it as long as they don’t make explicit drug claims on the label, though many products skirt this line with language about “supporting healthy testosterone levels.”
What This Means in Practice
If you’re considering Fadogia agrestis, the honest picture is this: the only controlled evidence for its hormonal effects comes from rat studies, the doses in most supplements are several times higher than what was traditionally used, and the same animal research that showed testosterone increases also showed signs of liver and kidney damage. There is no human data to confirm it works, to identify a safe dose, or to rule out serious side effects with repeated use. The gap between what’s marketed and what’s proven is unusually wide, even by supplement industry standards.