Fadogia Agrestis: 7 Critical Facts and Risks

Fadogia agrestis in brief

Three numbers sum up the evidence on fadogia agrestis. How many human trials exist, how many rat doses changed the testes, and how many tested products held none of the plant markers.

Every figure on this page comes from a PubMed abstract listed at the end. The human dose conversion is our own calculation with the standard method, and it is labelled as such. Nothing here is a dose recommendation.

What this guide covers

What is fadogia agrestis and why did it get popular?

Fadogia agrestis is a shrub from West Africa. Its stem is used in traditional medicine there for pain, inflammation and as an aphrodisiac (PMID 30170324).

It became popular in the West after it was talked about on health podcasts as a natural testosterone booster. Sales grew far faster than the science. The research behind those claims is a small set of rat studies. Three of the four come from the same research team (PMID 16281088, PMID 18023305, PMID 19755438).

It is now sold alone or mixed with tongkat ali in many "test booster" products. A 2020 study of 50 such boosters found that 90 percent claimed to raise testosterone. Only 24.8 percent of their ingredients had any data showing a rise (PMID 31385468).

What the fadogia agrestis rat studies showed

The testosterone study. In 2005, male rats got a water extract of the stem at 18, 50 or 100 mg per kg for 5 days. Their mating behaviour increased, and blood testosterone rose at all doses (PMID 16281088). This is the study behind most fadogia agrestis benefits claims.

The testes study. In 2008, the same group gave the same doses for 28 days. The extract changed many markers of testis function. The authors called these signs of adverse effects on the testes. Rats recovered on some markers, mainly at the lowest dose (PMID 18023305).

The liver and kidney study. In 2009, the group looked at the liver and kidneys of the same kind of rats. There were no outward signs of illness and no deaths. But enzymes leaked from liver and kidney cells into the blood, and a marker of cell damage rose. The authors suggested damage to the cell membranes (PMID 19755438).

The erection study. A 2023 study gave the extract to rats with drug induced erection problems. It restored several chemical markers of erection, similar to sildenafil (PMID 35969364). Again, these were rats.

Does fadogia agrestis increase testosterone in humans?

Nobody knows. We found no published trial of fadogia agrestis in people. There is no human data on testosterone, muscle, strength, fertility or safety.

Rat results often fail in people. Rats process plant compounds differently, and the doses per kilogram are not the same as in a capsule. That is why a rise in rat testosterone is a reason to study a plant, not a reason to take it.

Reviews of popular boosters show the same gap across the market. Of 191 studies on the 10 most common booster ingredients, only 19 percent were in humans; 53 percent were in animals (PMID 30770069).

The rat doses, converted to a person

Rat doses cannot simply be multiplied by your body weight. Scientists convert them with a body surface area method, because small animals burn through compounds faster (PMID 17942826, PMID 27057123).

The chart shows the three rat doses converted to a 70 kg person with that method. This is our calculation, not a figure from the studies, and it is not a dose suggestion.

Compare the serving on your label with this range. If it falls inside it, you are taking an amount similar to the rat doses that changed the testes, with no human safety data. This comparison is a rule of thumb, because rats and people also differ in other ways.

Fadogia agrestis side effects

Because there are no human trials, nobody has measured side effects in people. What we have is the rat data:

Fadogia agrestis and tongkat ali: unequal partners

Fadogia agrestis and tongkat ali are often sold together. They are not equal. Tongkat ali, also called Eurycoma longifolia, has human trials.

A 2022 review pooled 5 trials. Tongkat ali raised total testosterone in men, especially in men with low levels (PMID 36013514). In one uncontrolled study, 76 men with low testosterone took 200 mg a day for a month. The share with normal testosterone went from 35.5 to 90.8 percent (PMID 21671978).

In a small pilot study, 25 active adults aged 57 to 72 took 400 mg a day for 5 weeks. Total and free testosterone and grip strength rose in both men and women (PMID 23754792).

What labs found inside fadogia agrestis supplements

Even if fadogia agrestis worked, you would need the real plant in the capsule. A 2019 study built a lab test for 11 compounds found in the plant. Then it checked 17 supplements sold as fadogia agrestis.

Twelve products contained the plant compounds, adding up to 0.3 to 2.7 mg a day. Five contained none of them at all (PMID 30170324). That does not prove those five were fake, but it raises the question of what was in them.

Seven critical facts about fadogia agrestis

1. It is a West African shrub used in folk medicine. Mainly as a pain reliever and aphrodisiac (PMID 30170324).

2. Its testosterone rise was seen in rats, over 5 days. (PMID 16281088).

3. There is no published human trial. Not for testosterone, muscle or safety.

4. A 28 day rat study found testis changes at every dose. (PMID 18023305).

5. Rats also showed liver and kidney cell stress. (PMID 19755438).

6. Five of 17 tested products had none of the plant markers. (PMID 30170324).

7. Tongkat ali has human data; fadogia agrestis does not. (PMID 36013514).

So, is fadogia agrestis worth taking?

The case for it is one 5 day rat study showing more testosterone and mating behaviour (PMID 16281088). The case against is a 28 day rat study with testis changes at every dose (PMID 18023305). Add liver and kidney cell stress in rats (PMID 19755438), and no human trial at all.

Our take: fadogia agrestis is not worth the risk for most people. The evidence is all in rats, the warning signs are in the same rats, and product quality varies. If you want a herb with human data, tongkat ali and KSM 66 ashwagandha at least have trials. More guides sit on the supplements hub.