Fadogia agrestis

Fadogia agrestis

1. Identity

Botanical and Taxonomic Classification

Fadogia agrestis Schweinf. ex Hiern (synonym: Vangueria agrestis (Schweinf. ex Hiern) Lantz), belonging to the family Rubiaceae, is an African traditional medicinal plant also used as a dietary supplement in the United States. The synonym reflects a reclassification arising from molecular phylogenetic analyses of the tribe Vanguerieae within Rubiaceae; the name Vangueria agrestis is accepted in current botanical databases, although the name Fadogia agrestis remains universally used in the pharmacological and dietary supplement literature.

Fadogia agrestis Schweinf ex Hiern (Rubiaceae) is a shrub from 30 to 90 cm high, found from Guinea to Sudan. Also known in English as "Black aphrodisiac" and in Hausa as Baakin gagai, it is an erect shrub with yellowish and tomentellous leaves and stem. The family Rubiaceae—which also includes coffee (Coffea spp.) and gardenias—is notable for its diverse phytochemical profile.

Natural Distribution and Habitat

The plant is native to the savannah grasslands of West Africa, primarily Northern Nigeria. Its range extends from Guinea to Sudan, indicating a broad distribution across sub-Saharan Africa. Burkill's 1985 reference, The Useful Plants of West Tropical Africa, documents the species across at least eight West African languages spanning Burkina Faso, Mali, the Ivory Coast, and Ghana.

Plant Parts Used and Common Preparations

Historically, the stems and roots of Fadogia agrestis were most commonly prepared as decoctions or infusions, often consumed to support general vitality, reduce fatigue, and promote physical well-being. The stems of the plant are largely used in folklore medicine as an aphrodisiac. In West African traditional medicine, it has long been used as an aphrodisiac and vitality tonic, and modern supplement formulations typically use a concentrated stem extract to deliver their purported bioactive compounds.

In contemporary Western markets, Fadogia agrestis is sold as:

• Standardized stem extract capsules or tablets — the predominant commercial form.
• Powdered whole stem — milled dried stem material, used alone or blended into multi-ingredient formulas.
• Bulk powder — for preparation of aqueous decoctions, approximating the traditional preparation method.

An ultra-high-performance liquid chromatography (UHPLC) method was developed for the determination of 11 chemical constituents from both roots and aerial parts of F. agrestis, reflecting that phytochemical profiles vary across different plant parts.

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2. Traditional and Historical Use

Geographic Traditions and Time Period

Ethnobotanical evidence from sub-Saharan Africa indicates that Fadogia agrestis has historically been used to enhance the sexual performance of men, even long before the widespread adoption of Western pharmaceutical treatments. Burkill's 1985 reference documents the species across at least eight West African languages, and the Nigerian commercial trade in the stem material is centered around Hausa-speaking northern markets, where the local name Bakin gagai is recognized by older herbal traders.

Herbalists in Bauchi State in north-eastern Nigeria have employed Fadogia agrestis to improve sexual stamina and treat erectile difficulties. Fadogia agrestis is used in traditional African medicine as an analgesic and for anti-inflammatory and aphrodisiac activities.

Traditional Indications

In African traditional medicine, it is reputed for its fever-reducing utility, kidney pain alleviation, and diuretic effect. In the African traditional medicine, the decoction of this plant is extensively used as a febrifuge, which could be associated with its use as an antimalarial drug; in vitro antiplasmodial activity has been reported for extracts from leaves collected in Burkina Faso. This shrub is also mainly used as a diuretic plant and in the treatment of kidney pain and convulsions.

One of the standout applications in folk medicine has been as an aphrodisiac and tonic for reproductive health; traditional healers recommended its use to increase libido, enhance sexual performance, and support male virility, and it was also sometimes used to address symptoms related to infertility and erectile challenges.

Traditional Preparation Methods

The most consistent traditional preparation is a stem decoction: the harvested stem is cut into short lengths, pounded or shaved, then simmered in water for an hour or longer, with the resulting bitter dark-brown liquid taken in small cups over the course of a day. Traditional preparations also often involve infusions (teas) made from the roots or stems.

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3. Key Chemical Constituents and Active Compounds

Phytochemical Classes

The aqueous extract of the stem consists of saponins, alkaloids, anthraquinones, and flavonoids. Solvent-specific fractionation reveals additional classes: preliminary phytochemical screening of all extracts revealed the presence of reducing sugars, carbohydrates, and alkaloids; in addition, the chloroform extract showed the presence of saponins and flavonoids; the ethyl acetate extract contained terpenoids; and methanolic extracts contained saponins, steroids, terpenoids, and flavonoids.

Isolated and Characterized Compounds

Triterpenoid and benzophenone glycosides (roots): Four ursane-type triterpenoid glycosides and two benzophenone glycosides, along with one iridoid glucoside, were isolated and characterized from the dried roots of Vangueria agrestis; compounds 1 and 5 were identified as new metabolites. The identity of all compounds was established primarily by 1D and 2D NMR and HRESMS analysis.

Monoterpene glycosides (aerial parts and roots): Six monoterpene glycosides were isolated from Fadogia agrestis, established as derivatives of 2,6-dimethyl-2(E),6(Z)-octadiene-1,8-diol containing from two to four units of rhamnopyranose and, in three of them, one or two additional units of glucopyranose; in three of the compounds an acyl group of 8-hydroxy-2,6-dimethyl-2(E),6(Z)-octadienoyl was found esterifying the O-2 position of one of the units of rhamnopyranose.

Phenolic compounds: An UHPLC method was developed for the determination of 11 chemical constituents from both roots and aerial parts of F. agrestis. Twelve of 17 commercial dietary supplements analysed contained phenolic compounds in the range from 0.3 to 2.7 mg per daily serving.

Anti-infective glycosides: From the dried roots of Vangueria agrestis (also known as Fadogia agrestis), researchers isolated and characterized triterpenoid, benzophenone, and iridoid glycosides, with two new metabolites identified, some exhibiting anti-infective properties against Trypanosoma brucei.

Proposed Mechanisms of Action

The mechanism by which Fadogia agrestis stem extract increases serum testosterone in rodent models is proposed to involve its steroidal saponin content. Steroidal saponins are the constituents most often cited as relevant to the testosterone and libido discussion; saponins from related Rubiaceae and from the broader class of triterpenoid saponins are known to influence cholesterol-derived steroidogenesis pathways in the testes, which is the proposed mechanism by which Fadogia agrestis stem extract increases serum testosterone in rodent studies. This proposed mechanism has not been directly demonstrated in human cells or tissue.

The investigators in the foundational 2005 study concluded that the aqueous extract of Fadogia agrestis stem increased blood testosterone concentrations and that this may be the mechanism responsible for its aphrodisiac effects and various masculine behaviors.

Regarding its erectile-function-related activity, a 2022 rat study found that the aqueous extract of F. agrestis stem increased penile and testicular nitric oxide (NO), cGMP, catalase, SOD, total SH, GSH, and GST, and reduced acetylcholinesterase, PDE5, arginase, ACE, TBARS and H₂O₂ to levels comparable with sham controls; the study concluded that the extract restored the NO/cGMP pathway and ED-associated key enzymes via antioxidant means.

With respect to pain relief and inflammation: phytochemical screening of the stem bark extract revealed the presence of alkaloids and saponins, and the relieving effects of Fadogia agrestis are probably mediated by the influences of active components on both central and peripheral nociceptive pathways.

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4. Scientific Evidence by Area of Use

4.1 Testosterone and Reproductive Endocrinology

The foundational animal study (Yakubu et al., 2005): This study aimed to evaluate the phytochemical constituents and aphrodisiac potential of the aqueous extract of Fadogia agrestis (Rubiaceae) stem in male albino rats; the aqueous stem extract was screened for phytochemical constituents and male rats were orally dosed with 18 mg/kg, 50 mg/kg, and 100 mg/kg body weight, respectively, of the extract at 24-hour intervals, with sexual behavior parameters and serum testosterone concentration evaluated at days 1, 3, and 5.

At the lowest dose tested (18 mg per kg of body weight), testosterone levels roughly doubled compared to the control group; at a medium dose (50 mg/kg), they tripled; at the highest dose (100 mg/kg), they increased approximately sixfold. The increases were dose-dependent, meaning the more Fadogia agrestis the rats received, the higher their testosterone went.

All the doses resulted in a significant increase in mount frequency, intromission frequency, and significantly prolonged ejaculatory latency, as well as reduced mount and intromission latency; there was also a significant increase in serum testosterone concentrations in all the groups in a manner suggestive of dose-dependence.

Testicular function indices (Yakubu et al., 2008, Journal of Ethnopharmacology): This investigation was designed to evaluate the effect of chronic administration of the aqueous extract of Fadogia agrestis stem on some testicular function indices of male rats at the same doses used previously for the demonstration of aphrodisiac potentials. Compared with the control, extract administration for 28 days at all doses resulted in significant increase (p<0.05) in percentage testes-body weight ratio, testicular cholesterol, sialic acid, glycogen, acid phosphatase, and gamma-glutamyl transferase activities, while there was significant decrease (p<0.05) in the activities of testicular alkaline phosphatase, glutamate dehydrogenase, and concentrations of protein; recoveries were made by the animals on some of the testicular function indices mainly at 18 mg/kg body weight.

Evidence strength and human data: Fadogia agrestis, also known as black aphrodisiac, is traditionally used for its purported aphrodisiac, pro-erectile, anti-malarial, and anti-fever properties; research on this plant is scarce, with no human studies conducted to date. As of the current period, human clinical trials on Fadogia agrestis are extremely limited; there are no large-scale, randomised, placebo-controlled human studies confirming that Fadogia agrestis safely and effectively increases testosterone in men. The evidence for testosterone-raising activity is therefore entirely preclinical (animal models), and its translation to humans is unknown.

4.2 Sexual Behavior and Erectile Function

In addition to the testosterone data, the 2005 Yakubu study demonstrated improved sexual behavior parameters in rats at all tested doses, as described above. A 2022 PubMed-indexed rat study further examined the pro-erectile mechanism: inadequate release of nitric oxide (NO) by the penile tissue impacts negatively on penile erection causing erectile dysfunction (ED); Fadogia agrestis has been implicated in the management of ED, and this study evaluated the influence of aqueous extract of Fadogia agrestis stem on key biomolecules associated with ED in the penile and testicular tissues of male Wistar rats induced with ED by paroxetine. The study concluded that the extract restored the NO/cGMP pathway and ED-associated key enzymes in the penile and testicular tissues via antioxidant means and recommended the use of aqueous extract of Fadogia agrestis stem in managing ED after clinical trials.

Evidence strength: All data on sexual behavior and erectile function are from rodent studies only. No human clinical trials exist. The authors of the 2022 study themselves explicitly called for clinical trials before clinical application.

4.3 Analgesic and Anti-inflammatory Activity

Analgesic and anti-inflammatory activities of an aqueous extract produced from Fadogia agrestis stem bark were investigated using animal models; significant dose-dependent increases in reaction time in the tail-flick test and inhibition of writhing in the visceral pain test (with intraperitoneal injections of acetic acid, p < 0.001, compared with the control) were observed; in an anti-inflammatory investigation, significant dose-dependent inhibitions in the carrageenan-induced paw edema and cotton-pellet granuloma tests were also found. The extract in the highest non-sedative dose tested (200 mg/kg) demonstrated a potency comparable with that of the reference analgesic anti-inflammatory drug acetylsalicylate (aspirin, 100 mg/kg).

The aqueous extract from the stem bark collected from Nigeria was found to possess anti-inflammatory property, which was assumed to be due to the presence of flavonoids.

Evidence strength: These findings are from rodent models only (tail-flick, acetic acid writhing, carrageenan paw edema). No human analgesic or anti-inflammatory trials have been conducted.

4.4 Antimalarial / Antiplasmodial Activity

In African traditional medicine, the decoction of Fadogia agrestis is extensively used as a febrifuge, which could be associated with its use as an antimalarial drug; in vitro antiplasmodial activity has been reported for extracts from leaves collected in Burkina Faso. An ethnobotanical survey in Burkina Faso identified Fadogia agrestis for antimalarial properties, and the plant extracts showed notable antiplasmodial activity against a chloroquine-resistant strain of Plasmodium falciparum.

Further phytochemical work with isolated glycosides from roots found anti-infective activity: compounds 6 and 2 (isolated ursane-type and benzophenone glycosides) showed inhibitory effect against Trypanosoma brucei with IC₅₀ of 22.3 µM for compound 6 and IC₅₀ of 11.1 µM, IC₉₀ of 12.3 µM for compound 2. Additionally, compound 20 (a monoterpene rhamnoside) showed weak antiplasmodial activity against chloroquine-sensitive (D6) and resistant (W2) Plasmodium falciparum with IC₅₀ values of 3.29 µg/mL and 4.53 µg/mL, respectively.

Evidence strength: Antimalarial and anti-infective data are entirely in vitro and from ethnobotanical surveys. No controlled clinical trials in malaria patients have been conducted.

4.5 Antibacterial Activity

The aqueous extract of Fadogia agrestis has been reported to possess antibacterial activity, as well as ameliorative activity against alloxan-induced diabetic rats and in vitro antiplasmodial effects. Antibacterial testing of stem extracts against gram-positive and gram-negative bacteria has been reported in the scientific literature, but minimum inhibitory concentration values and bacterial species tested vary across studies, and no clinical antibacterial applications have been validated.

Evidence strength: Preliminary, in vitro or animal only. No human data.

4.6 Antidiabetic Activity

Ameliorative activity against alloxan-induced diabetic rats has been reported for the aqueous extract. This represents a single preclinical line of inquiry with no follow-up human research identified in the scientific literature.

Evidence strength: Single animal study; no human data.

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5. Body Systems and Health Areas of Association

• Male reproductive and endocrine system: The plant is most prominently associated with testosterone biosynthesis, testicular function, and male sexual behavior based on rodent data.
• Penile/erectile physiology: Animal evidence points to modulation of the NO/cGMP pathway relevant to erection.
• Musculoskeletal / pain pathways: Rodent studies indicate central and peripheral analgesic activity and anti-inflammatory effects.
• Immune and infectious disease (antimalarial/antibacterial): In vitro antiplasmodial and antibacterial activity have been identified in isolated phytochemical fractions.
• Liver and kidney (toxicological concern): Preclinical data reveal alterations in hepatic and renal biomarkers with repeated dosing (see Safety section).
• Metabolic (antidiabetic): A single rodent study documents blood-glucose-lowering effects in alloxan-induced diabetes.

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6. Dosage Forms and Reported Dosages

All dosages with quantitative data arise from animal (rat) studies. No evidence-based human dosage recommendation exists.

Doses used in rodent research:

• Male rats were orally dosed with 18 mg/kg, 50 mg/kg, and 100 mg/kg body weight, respectively, of the aqueous extract at 24-hour intervals, with sexual behavior parameters and serum testosterone concentration evaluated at days 1, 3, and 5.
• The mode of cellular toxicity study used the same dose range of 18, 50, and 100 mg/kg body weight of the aqueous extract, administered orally for 28 days.
• The highest non-sedative dose tested for analgesic/anti-inflammatory activity was 200 mg/kg, which demonstrated potency comparable to aspirin at 100 mg/kg.
• In the paroxetine-induced ED study, paroxetine-induced ED rat groups received AEFAS (aqueous extract of Fadogia agrestis stem) at 18, 50, and 100 mg/kg body weight respectively.
• High single-dose oral studies in rodents found no deaths up to 2,000–5,000 mg/kg for leaf hydroalcoholic extract and root aqueous extract, suggesting low acute lethality.

Commercial supplement dosages: Supplements online offer dosages from 400 mg to 2,500 mg each day; this wide variance is concerning because there are no established, evidence-based dosage recommendations for humans, the doses used in the small animal studies do not directly match these amounts, and without proper clinical trials, it is unknown what a safe or effective dose is for people.

The recovery made at the dose of 18 mg/kg body weight (the dose used in folklore medicine in the rat model) suggests that it does not exhibit permanent toxicity at this dose in rodents. Extrapolation of rodent mg/kg doses to human equivalent doses requires allometric scaling and carries substantial uncertainty; no validated human equivalent dose has been published for Fadogia agrestis.

According to the 2026 WADA (World Anti-Doping Agency) List of Prohibited Substances, Fadogia agrestis is not prohibited.

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7. Safety Considerations

Overview of the Preclinical Safety Evidence Base

The effects of Fadogia agrestis extract on liver and kidney function indices, haematological parameters, reproductive function, testicular functions and histology, lipid profile, and its mode of cellular toxicity have been scientifically validated in a series of studies by Yakubu et al. (2006, 2007a, 2007b, 2008a, b, c, 2009). All of these studies were conducted in male rats. Research on Fadogia agrestis toxicity is almost entirely preclinical (rodents, in vitro), plus one recent human case report; no controlled human safety trials have been found.

Testicular Toxicity

Histopathological changes revealed destruction of spermatic cells and seminiferous tubules; toxicity was mild and reversible at the 18 mg/kg body weight dose regimen, but there was irreversible derangement of male testicular histology at 50 and 100 mg/kg body weight dose regimens, which may adversely affect reproductive function. The alterations brought about by the aqueous extract of Fadogia agrestis stem are indications of adverse effects on male rat testicular function and may adversely affect the functional capacities of the testes.

Hepatotoxic and Nephrotoxic Signals

The mode of cellular toxicity of the aqueous extract of Fadogia agrestis stem in male rats was investigated in a dedicated study. Clinical toxicity symptoms such as respiratory distress, epistaxis, salivation, hypo- and hyperactivity were not observed at any period of the experiment, and no mortality was recorded; however, extract administration significantly reduced (p < .05) the activities of alkaline phosphatase, lactate dehydrogenase, and gamma glutamyl transferase in the liver and kidney with corresponding increases in the serum, and serum malondialdehyde also increased significantly in all the extract-treated groups. The authors of that study (Yakubu et al., 2009, Human and Experimental Toxicology) proposed that disruption of the ordered lipid bilayer of the plasma membranes of the hepatocytes and nephrons, made possible by the functional groups or products of metabolism of the extract, may be responsible for the cellular toxicity observed.

Dose-Dependence of Toxicity

Across the rodent literature, a consistent dose-dependent pattern has emerged: recoveries were made by the animals on some testicular function indices mainly at 18 mg/kg body weight, and the recovery made at this dose (as used in folklore medicine) suggests that it does not exhibit permanent toxicity at this dose in rats. Higher doses (50 and 100 mg/kg) were associated with irreversible histopathological damage in the testes. Whether this dose-response relationship applies to humans at the commercially marketed doses is entirely unknown, as no human data exist.

Species Adulteration and Product Quality

A practically important quality concern relates to botanical identity in commercial products. Due to the nature of the unregulated herbal industry, traces of highly toxic Fadogia homblei and Fadogia cienkowskii species can be found in some Fadogia agrestis supplements. A published UHPLC-PDA-MS method for identity authentication addresses this concern: phenolic compounds were not detected in five of seventeen dietary supplements tested, and a liquid chromatography–mass spectrometry method coupled with electrospray ionization was developed for the identification and confirmation of compounds from plant samples and dietary supplements claiming to contain F. agrestis. The developed method is described as simple, economic, rapid, and suitable for quality control and chemical fingerprint analysis of F. agrestis.

Drug Interactions

There is currently not enough research to identify potential drug interactions with Fadogia agrestis; no clinically significant interactions have been formally identified. Given the demonstrated effects on hepatic and renal enzyme activities in rodent studies, concomitant use with hepatotoxic or nephrotoxic substances represents a theoretical concern that has not been studied in humans.

Absence of Human Safety Data

To date, a comprehensive Fadogia agrestis human study does not exist; there are a total of only a small number of studies on Fadogia agrestis, conducted in rats. The complete absence of human pharmacokinetic, pharmacodynamic, and safety data means that the translational relevance of the animal toxicology findings — whether they predict meaningful human organ risk at typical supplement doses — cannot be determined from the existing literature.

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Summary of Evidence Quality

The scientific literature on Fadogia agrestis is characterized by a small number of studies — primarily from a single research group at the University of Ilorin, Nigeria — conducted entirely in rodent models or in vitro. Fadogia agrestis has been studied for a variety of conditions, notably for its potential to enhance sexual performance and boost testosterone levels in men, and has also been researched for its anti-inflammatory and analgesic properties and potential effects on endurance and athletic performance; however, research is limited and primarily consists of animal studies. Some studies suggest that Fadogia agrestis may increase sexual behavior and testosterone levels in rats, but there is a lack of robust clinical trials to confirm these effects in humans, meaning its efficacy in treating these conditions is still uncertain and should be approached with caution. The safety signals identified in animal studies — particularly dose-dependent testicular histopathological damage and perturbations in liver and kidney biomarkers — have not been characterized in humans. Until properly powered, randomized, controlled human trials are conducted, both the efficacy and the safety profile of Fadogia agrestis in people remain unestablished.

References

• Yakubu MT, Akanji MA, Oladiji AT. Aphrodisiac potentials of the aqueous extract of Fadogia agrestis (Schweinf. Ex Hiern) stem in male albino rats. Asian Journal of Andrology. 2005;7(4):399–404. PubMed PMID 16281088.
• Yakubu MT, Akanji MA, Oladiji AT. Effects of oral administration of aqueous extract of Fadogia agrestis (Schweinf. Ex Hiern) stem on some testicular function indices of male rats. Journal of Ethnopharmacology. 2008;115(2):288–292. ScienceDirect.
• Yakubu MT, Oladiji AT, Akanji MA. Mode of cellular toxicity of aqueous extract of Fadogia agrestis (Schweinf. Ex Hiern) stem in male rat liver and kidney. Human & Experimental Toxicology. 2009;28(8):469–478. SAGE Journals.
• Osman AG, et al. Glycosides of ursane-type triterpenoid, benzophenone, and iridoid from Vangueria agrestis (Fadogia agrestis) and their anti-infective activities. PubMed PMID 30325205.
• Anero R, et al. Monoterpene glycosides isolated from Fadogia agrestis. Phytochemistry. 2008;69(3):805–811. PubMed PMID 17988698.
• Quantification of Phenolic Compounds from Fadogia agrestis and Dietary Supplements using UHPLC-PDA-MS. PubMed PMID 30170324.
• Fadogia agrestis Stem Extract Restores Selected Biomolecules of Erectile Dysfunction in Paroxetine-Treated Wistar Rats. PubMed PMID 35969364.
• Oyekunle OA, Okojie AK, Udoh US. Analgesic and Anti-Inflammatory Effects of an Extract of Fadogia agrestis in Rats. Neurophysiology. 2010;42(2):124–129. Springer.
• Anero R, et al. Monoterpene glycosides isolated from Fadogia agrestis. Phytochemistry. ScienceDirect.
• Microscopic characterization and HPTLC of the leaves, stems and roots of Fadogia agrestis — an African folk medicinal plant. Revista Brasileira de Farmacognosia. ScienceDirect.
• Effect of repeated administration of the aqueous extract of Fadogia agrestis stem on the male rat testicular histology. International Scholars Journals.
• Examine.com. Fadogia agrestis — benefits, dosage, and side effects. Examine.com.
• Chemical Constituents From Fadogia Agrestis. Thieme Connect.
• Antimicrobial activity, cytotoxic test and phytochemical screening of the extracts of the stem of Fadogia agrestis. ResearchGate.
• Three undescribed monoterpene rhamnosides from the aerial parts of Vangueria agrestis. ResearchGate / Natural Product Research.
• Antioxidant and Antiplasmodial Activities of Extracts from Gardenia erubescens and Fadogia agrestis. Scientific Research Publishing.
• NutraPedia — Fadogia agrestis. NutraHacker.