Irvingia Gabonensis (African Mango) and Body Weight Research

Table of Contents

1. The Tree and Its Seed
2. Ogbono Soup and Traditional Food Use
3. What the Seed Contains
4. The Cameroon Trials of 2005 and 2009
5. The Cissus Combination Trial
6. Later Trials in Mexico and Thailand
7. What the Systematic Reviews Concluded
8. Safety Findings
9. What the Laboratory Found in Products
10. What Is Not Known
11. Key Research Papers
12. Connections
13. Featured Videos

The Tree and Its Seed

A 2020 food-science review describes Irvingia gabonensis as a multipurpose fruit tree native to tropical Africa and a priority indigenous fruit tree in western and central Africa: its wood is used for making utensils, and its fruits are used mostly as food and medicine. A 2024 review of the plant's traditional uses lists Equatorial Guinea, Nigeria, Gabon and Cameroon among the countries where it grows. Despite the English name, it is a different tree from the common mango; the dika nut belongs to the family Irvingiaceae.

The fruit has two parts that people use in very different ways:

• The flesh (mesocarp). The 2020 review reports that the fruit pulp contains various plant compounds and a vitamin C concentration higher than some fruits known for vitamin C. It is eaten fresh or dried, pressed into juice, made into wine, or used as a flavouring.
• The seed kernel (dika nut). Inside the hard stone sits an oily kernel. This is the part that is dried, ground and cooked into soups, and it is also the part from which the weight-loss extracts are made.

The 2024 review of traditional uses records a wide folk pharmacy built around the tree. The ripe pulp is reported in tradition for diarrhoea, diabetes, ulcers and liver protection; the bark for dysentery, colic, scabies, toothache and skin conditions; and in Senegal the stem bark for gonorrhoea, liver disorders and digestive complaints. Of the seeds, the review states that they "have folkloric uses for weight loss and are popular as blood thinners and anti-diabetics". These are reports of traditional use, collected by the reviewers, not results of trials.

Ogbono Soup and Traditional Food Use

In everyday West African cooking, the dika kernel is a thickener. A 2011 study from Cameroon describes how the kernels, once dried and crushed, are used to prepare "a sticky and aromatic soup" widely eaten in Cameroon and West African countries. In Nigeria the same soup is called ogbono soup, and the ground kernel itself is often called ogbono.

Food scientists have studied why the ground kernel behaves this way in a pot:

• A 1997 study compared three African soup thickeners — okra, dika nut and khan — and found that okra and dika nut acted more as thickeners than as stabilisers of the oil-in-water mixture that a soup is, while khan did both.
• A 2014 study isolated the main carbohydrate of the seed's inner tissue (endosperm). It is an arabinogalactan, a large branched sugar chain with small amounts of other sugars, with a very high molecular weight of about 1.56 million g/mol, and the authors concluded it has potential as a thickener.
• A 2015 study that developed an instant ogbono soup mix found that plain dika kernel powder had the highest water absorption, swelling capacity and bulk density of the samples tested, which the authors attributed to its high crude fibre and low moisture. In taste tests the 100% kernel powder gave a good soup, though with less nutritional value than mixes that added crayfish and stockfish.
• The same mucilage has been tested outside the kitchen. A 2005 pharmaceutics study used dika nut mucilage as a binding agent in tablets and found it could give a range of tablet strengths and drug-release times compared with gelatin.

This long food use is the background to the weight-loss research. The early Cameroon trial framed its question around fibre: its abstract opens with the statement that dietary fibres are frequently used for the treatment of obesity, and then tests the seed.

What the Seed Contains

The dika kernel is mostly fat. The 2020 food-science review gives the kernel's crude fat as 63% to 69%, made up mainly of myristic and lauric acids, and its make-up of fats means it is solid at room temperature. The 2024 traditional-use review agrees that oil is the major constituent of the seed and that it is mainly myristic and lauric acids.

Other findings on the kernel:

• Fibre and gum. The thickening fraction is the arabinogalactan gum described above; the instant-soup study measured high crude fibre in the plain kernel powder. The abstracts read for this page do not give a single fibre percentage for the kernel.
• Polyphenols. The 2020 review reports that 41 phenolic compounds have been identified in the seeds and in extracts and supplements made from them, with ellagic acid and its derivatives the most common. A 2012 United States Department of Agriculture laboratory analysis found ellagic acid, mono-, di- and tri-O-methyl-ellagic acids and their glycosides as major components of the seeds. A 2023 study isolated seventeen compounds from the defatted kernel, including four flavonoid glycosides and five ellagic acid derivatives, two of them not described before.
• Minerals and phytate. A 2004 Nigerian analysis of seven wild seeds, including the dika nut, reported high protein (6.5% to 24.2% across the seeds), fat (19.0% to 58.5%) and minerals, with phytate of 1043.6 to 2905.2 mg per 100 g. For the dika nut and two other seeds, the calculated calcium-phytate-to-zinc ratio was above the critical level, which the authors read as a sign of reduced zinc availability from the seed.

One animal study looked at the fat itself as food. In a 2011 study, young rats were fed diets containing 0%, 5.1%, 7.34% or 13.48% dika nut fat for three weeks. In rats, total cholesterol rose significantly, and the rise was due to HDL cholesterol; at the highest dose the fat altered cholesterol and triglycerides significantly, and male rats on all three test diets had a significantly lower liver weight than controls.

The 2024 traditional-use review notes that, despite their widespread use, extracts of the plant "are still inadequately characterized phytochemically". The research does not settle which compound, if any, would be responsible for the effects reported in the weight trials.

The Cameroon Trials of 2005 and 2009

The first human weight trials came from one research group at the University of Yaoundé I in Cameroon. Their abstracts report the following.

2005: ground seed, one month

• Design. Double-blind, randomised; 40 obese people, mean age 42.4 years.
• Groups. 28 received the seed and 12 received placebo — an unequal split.
• Dose. The trial gave 1.05 g of Irvingia gabonensis three times a day for one month.
• Diet. All participants ate a normal-calorie diet, checked every week with a food diary.
• Weight. Mean body weight fell by 5.26% (±2.37%) in the seed group and by 1.32% (±0.41%) in the placebo group; the difference between groups was reported as significant.
• Lipids. The seed group showed significant decreases in total cholesterol, LDL cholesterol and triglycerides and an increase in HDL cholesterol; the placebo group showed no changes in blood lipids.

2009: seed extract, ten weeks

• Design. Randomised, double-blind, placebo-controlled; 102 healthy overweight or obese volunteers (body mass index above 25).
• Dose. The trial gave 150 mg of a seed extract or a matching placebo 30 to 60 minutes before lunch and before dinner, that is, 150 mg twice daily.
• Measurements. Body measures and blood tests at baseline and at 4, 8 and 10 weeks.
• Results. The abstract reports significant improvements in body weight, body fat and waist circumference, and in total cholesterol, LDL cholesterol, blood glucose, C-reactive protein, adiponectin and leptin, in the extract group compared with placebo. The abstract does not give the size of the weight change in kilograms.
• The authors' framing. The authors called it the first double-blind randomised placebo-controlled trial of an Irvingia gabonensis extract for obesity and lipids, and said the results provided impetus for much larger clinical studies. They based the idea on their own earlier cell study, which they describe as showing effects on fat-cell development through PPAR-gamma, leptin, adiponectin and glycerol-3-phosphate dehydrogenase; that work was done in cells, not people.

These two trials, together with the combination trial below, are the three studies on which the first systematic review was based.

The Cissus Combination Trial

In 2008 the same Yaoundé group tested two capsule formulas against placebo: Cissus quadrangularis alone, and Cissus combined with Irvingia gabonensis.

• Design. Ten-week randomised, double-blind, placebo-controlled trial; 72 overweight or obese adults (45.8% men, 54.2% women; ages 21 to 44; mean age 29.3), divided into three equal groups of 24.
• Dose. Capsules were taken twice daily before meals. The abstract does not state the amount of either plant in the capsules.
• Lifestyle. No major dietary changes or exercise were suggested.
• Measurements. Body weight, body fat, waist size, total cholesterol, LDL cholesterol and fasting blood glucose, at baseline and at 4, 8 and 10 weeks.
• Results. Both active groups differed significantly from placebo on all six measures by week 10, with differences visible by week 4. The Cissus-alone group showed significant reductions; the combination group showed even larger ones.

The authors described the combination as "apparently synergistic". Because the extra effect in the combination arm came from adding a second plant, this trial is evidence about two plants at once, a point the site's Cissus weight trials page examines from the Cissus side.

Later Trials in Mexico and Thailand

Two later trials came from research groups outside Cameroon.

Mexico, 2018: metabolic syndrome

• Design. Randomised, double-blind, placebo-controlled; 24 people with metabolic syndrome by International Diabetes Federation criteria, 12 per group.
• Dose. The trial gave 150 mg of Irvingia gabonensis twice a day for 90 days.
• Results within the Irvingia group. Waist circumference fell from 94.0 to 91.0 cm; glucose at 120 minutes of a glucose tolerance test fell from 8.8 to 7.6 mmol/L; triglycerides fell from 2.5 to 2.0 mmol/L; VLDL cholesterol and the glucose area under the curve also fell.
• Remission. Seven of 12 people (58.3%) in the Irvingia group no longer met the criteria for metabolic syndrome, compared with two of 12 (16.7%) on placebo (P = 0.045).
• Body weight. The abstract does not report body weight as an outcome.

Thailand, 2022: twelve weeks, no difference in metabolism

• Design. Overweight or obese adults first spent 12 weeks having their weight monitored, then were randomised to kernel extract or placebo.
• Dose. The trial gave one 300 mg tablet of Irvingia gabonensis kernel extract per day for 12 weeks.
• Results. Compared with placebo, the extract raised plasma vitamin C at 6 and 12 weeks and serum adiponectin at 3 weeks. The abstract reports no differences between groups in metabolism, inflammation, telomere length or aerobic capacity after supplementation.
• Funding. The paper states it was funded by a supplement manufacturer, which the authors say had no role in the study design, analysis or publication.

The Thai trial is the first one on this page in which the headline metabolic measures did not separate from placebo.

What the Systematic Reviews Concluded

Independent reviewers have pooled these trials several times. Their conclusions, as stated in their abstracts:

Onakpoya and colleagues, 2013

This systematic review from the University of Exeter searched for randomised controlled trials of Irvingia gabonensis for body weight in overweight and obese people. It found three trials and included all three. The reviewers report that all three "had flaws in the reporting of their methodology". All three reported statistically significant reductions in body weight and waist circumference favouring the seed over placebo, and the results suggested positive effects on blood lipids. Adverse events included headache and sleep difficulty. Their conclusion: because of the paucity and poor reporting quality of the trials, the effects on body weight and related measures "are unproven", and the seed "cannot be recommended as a weight loss aid". They called for more rigorous and better-reported research.

Lee and colleagues, 2020

This systematic review and meta-analysis found five randomised trials of the seed extract. Four of the five were rated at high risk of bias; only one was rated at low risk of bias. Pooled together, the five trials showed a significant decrease in body weight, body fat and waist circumference, and beneficial effects on total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides. However, the one low-risk-of-bias trial did not show significantly different outcomes; it showed only a trend toward higher HDL cholesterol (net change 11.61%, 95% confidence interval −6.12% to 29.34%) and lower triglycerides (net change −29%, 95% confidence interval −76% to 19%), both intervals crossing zero. Reported adverse events were minor. The reviewers concluded that overall efficacy "seems positive but is limited due to poor methodological quality and the insufficient reporting of the clinical trials", and that further high-quality trials are needed.

Maunder and colleagues, 2020

This review of 54 placebo-controlled trials of herbal medicines for weight loss counted a weight difference of 2.5 kg or more as clinically significant. For herbs with three or fewer trials, it reported statistically and clinically significant weight loss for Irvingia gabonensis (among others, including Cissus quadrangularis), but said these findings must be interpreted cautiously because of the small number of studies, generally poor methodological quality and poor reporting of the herbal interventions. Its overall conclusion was that there is currently insufficient evidence to recommend any of the herbal medicines in the review for weight loss.

Wiyarta and colleagues, 2025

This network meta-analysis of 39 trials (2,513 participants) of plant products for overweight and obesity ranked African mango as the most effective intervention, with a mean reduction in body weight of 10.00 kg (95% confidence interval 3.26 to 16.74 kg), waist circumference of 11.70 cm, total cholesterol of 44.01 mg/dL and triglycerides of 42.65 mg/dL. The authors note that there were too few direct comparisons, so most comparisons were indirect through placebo, and that further high-quality, rigorous studies are needed to establish clinical efficacy.

Read together: every review found that the trials report weight loss, and every review found the trials too few, too small or too poorly reported to establish the effect. In the 2020 meta-analysis the pooled weight loss rests mainly on trials the reviewers judged at high risk of bias, and the one trial they judged at low risk of bias did not find significantly different outcomes.

Safety Findings

• In the trials. The 2013 review lists headache and sleep difficulty among the adverse events reported; the 2020 meta-analysis describes the reported adverse events across five trials as minor. The 2020 herbal-medicine review notes that most herbal medicines appeared safe over the short duration of the studies, commonly 12 weeks or less.
• In rats. A 2012 90-day study gave rats a seed extract by tube at 0, 100, 1000 and 2500 mg per kg of body weight per day. In rats, it found no treatment-related changes in clinical signs, body weight, blood tests, urine, organ weights or tissue examination, and the extract showed no genetic toxicity in the bacterial (Ames), chromosome-damage and micronucleus tests. The no-observed-adverse-effect level was 2500 mg/kg per day or more, the highest dose tested.
• A kidney case report. A 2015 case report from Turkey describes a 42-year-old patient with chronic kidney disease who became dependent on dialysis after rapid worsening of kidney function following 2.5 months of African mango use. The authors describe it as, to their knowledge, the first case of chronic kidney failure developing in association with African mango. A single case report shows an association in one person; it does not establish that the product caused the kidney failure.
• Zinc. The 2004 seed analysis found a phytate-to-zinc ratio in the dika nut above the level linked to reduced zinc availability. That is a finding about the whole seed as food, not about extract capsules.

The 2024 traditional-use review summarises the toxicity studies as showing the relative safety of the extract "at the administered doses". None of the trials described on this page gave the seed or extract for longer than 12 weeks.

What the Laboratory Found in Products

Two laboratory studies looked at what is actually inside products sold under the African mango name.

• The 2012 United States Department of Agriculture study notes that dietary supplements based on African mango seed extract were among the popular herbal weight-loss supplements on the United States market and that the extract "is believed to be a natural and healthy way to lose weight", but that the chemical composition of these supplements had never been reported. It analysed seeds, a seed extract and several commercial supplements and proposed the ellagic acid compounds as markers for quality control.
• A 2014 study set out to isolate active compounds from a commercial African mango sample and found that the sample was contaminated with goji berry (Lycium species). The compounds it isolated were absent from an authenticated African mango sample but present in three authentic goji berry samples, and microscopy showed goji berry features in the commercial product.

These findings matter for reading any trial or product claim: a capsule labelled as African mango is not guaranteed to contain only the seed, and the trials used several different preparations — ground seed at 1.05 g three times a day, extracts at 150 to 300 mg a day, and a two-plant formula.

What Is Not Known

• Whether the effect is real at the size reported. The only trial rated at low risk of bias in the 2020 meta-analysis did not show significantly different outcomes.
• Independent replication. The three trials that produced the largest early results all came from one research group, and the abstracts read for this page include no large, well-reported trial from an independent group confirming them.
• Long-term outcomes. No trial described here gave the seed or extract for more than 12 weeks, so weight maintenance, regain and long-term safety are unmeasured.
• The active ingredient. The kernel is mostly saturated fat with an arabinogalactan gum and ellagic-acid compounds; reviewers state the extracts are still inadequately characterised, and the trials do not show which component, if any, is responsible.
• Mechanism in people. The fat-cell gene findings come from cells. The changes in leptin and adiponectin seen in some trials are measurements, not proof of how weight might change.
• The food versus the capsule. No trial on this page tested ogbono soup as normally eaten; the 2005 trial used ground seed in capsules, and the later trials used extracts.
• Kidney risk. One case report describes kidney failure after use; how often, if ever, this happens is unknown.

Key Research Papers

1. Onakpoya I, Davies L, Posadzki P, Ernst E. The efficacy of Irvingia gabonensis supplementation in the management of overweight and obesity: a systematic review of randomized controlled trials. J Diet Suppl. 2013;10(1):29-38. PubMed PMID: 23419021
2. Lee J, Chung M, Fu Z, Choi J, Lee HJ. The Effects of Irvingia gabonensis Seed Extract Supplementation on Anthropometric and Cardiovascular Outcomes: A Systematic Review and Meta-Analysis. J Am Coll Nutr. 2020;39(5):388-396. PubMed PMID: 31855111
3. Maunder A, Bessell E, Lauche R, Adams J, Sainsbury A, Fuller NR. Effectiveness of herbal medicines for weight loss: A systematic review and meta-analysis of randomized controlled trials. Diabetes Obes Metab. 2020;22(6):891-903. PubMed PMID: 31984610
4. Wiyarta E, Budiman RA, Subroto DRT, Park MN, Mayulu N, Taslim NA, Tjandrawinata RR, Tallei TE, Hardinsyah H, Nurkolis F, Kim B. Plant-Derived Natural Products for Dietary Intervention in Overweight and Obese Individuals: A Systematic Review and Network Meta-Analysis. Phytother Res. 2025. PubMed PMID: 40420357
5. Ngondi JL, Oben JE, Minka SR. The effect of Irvingia gabonensis seeds on body weight and blood lipids of obese subjects in Cameroon. Lipids Health Dis. 2005;4:12. PubMed PMID: 15916709
6. Ngondi JL, Etoundi BC, Nyangono CB, Mbofung CM, Oben JE. IGOB131, a novel seed extract of the West African plant Irvingia gabonensis, significantly reduces body weight and improves metabolic parameters in overweight humans in a randomized double-blind placebo controlled investigation. Lipids Health Dis. 2009;8:7. PubMed PMID: 19254366
7. Oben JE, Ngondi JL, Momo CN, Agbor GA, Sobgui CS. The use of a Cissus quadrangularis/Irvingia gabonensis combination in the management of weight loss: a double-blind placebo-controlled study. Lipids Health Dis. 2008;7:12. PubMed PMID: 18377661
8. Méndez-Del Villar M, González-Ortiz M, Martínez-Abundis E, Pérez-Rubio KG, Cortez-Navarrete M. Effect of Irvingia gabonensis on Metabolic Syndrome, Insulin Sensitivity, and Insulin Secretion. J Med Food. 2018;21(6):568-574. PubMed PMID: 29336718
9. Nonsa-Ard R, Aneknan P, Tong-Un T, Honsawek S, Leelayuwat N. Effects of Irvingia gabonensis Extract on Metabolism, Antioxidants, Adipocytokines, Telomere Length, and Aerobic Capacity in Overweight/Obese Individuals. Nutrients. 2022;14(21):4646. PubMed PMID: 36364907
10. Kothari SC, Shivarudraiah P, Venkataramaiah SB, Gavara S, Soni MG. Subchronic toxicity and mutagenicity/genotoxicity studies of Irvingia gabonensis extract (IGOB131). Food Chem Toxicol. 2012;50(5):1468-79. PubMed PMID: 22386809
11. Özkan G, Ulusoy Ş. A case of renal failure developing in association with African mango consumption. Int J Clin Exp Med. 2015;8(4):6374-8. PubMed PMID: 26131261
12. Mateus-Reguengo L, Barbosa-Pereira L, Rembangouet W, Bertolino M, Giordano M, Rojo-Poveda O, Zeppa G. Food applications of Irvingia gabonensis (Aubry-Lecomte ex. O'Rorke) Baill., the 'bush mango': A review. Crit Rev Food Sci Nutr. 2020;60(14):2446-2459. PubMed PMID: 31366215
13. Hassan YR, El-Shiekh RA, El Hefnawy HM, Michael CG. Irvingia gabonensis baill. (African Mango): A comprehensive review of its ethnopharmacological significance, unveiling its long-standing history and therapeutic potential. J Ethnopharmacol. 2024;326:117942. PubMed PMID: 38395180
14. Nangue TJ, Womeni HM, Mbiapo FT, Fanni J, Michel L. Irvingia gabonensis fat: nutritional properties and effect of increasing amounts on the growth and lipid metabolism of young rats wistar sp. Lipids Health Dis. 2011;10:43. PubMed PMID: 21375740
15. Nwokocha LM, Williams PA. Hydrodynamic and rheological properties of Irvingia gabonensis gum. Carbohydr Polym. 2014;114:352-356. PubMed PMID: 25263901
16. Ndjouenkeu R, Akingbala JO, Oguntimein GB. Emulsifying properties of three African food hydrocolloids: okra (Hibiscus esculentus), dika nut (Irvingia gabonensis), and khan (Belschmiedia sp.). Plant Foods Hum Nutr. 1997;51(3):245-55. PubMed PMID: 9629864
17. Bamidele OP, Ojedokun OS, Fasogbon BM. Physico-chemical properties of instant ogbono (Irvingia gabonensis) mix powder. Food Sci Nutr. 2015;3(4):313-8. PubMed PMID: 26288723
18. Odeku OA, Patani BO. Evaluation of dika nut mucilage (Irvingia gabonensis) as binding agent in metronidazole tablet formulations. Pharm Dev Technol. 2005;10(3):439-46. PubMed PMID: 16176024
19. Oboh G, Ekperigin MM. Nutritional evaluation of some Nigerian wild seeds. Nahrung. 2004;48(2):85-7. PubMed PMID: 15146961
20. Sun J, Chen P. Ultra high-performance liquid chromatography with high-resolution mass spectrometry analysis of African mango (Irvingia gabonensis) seeds, extract, and related dietary supplements. J Agric Food Chem. 2012;60(35):8703-9. PubMed PMID: 22880691
21. Zulfiqar F, Ali Z, Viljoen AM, Chittiboyina AG, Khan IA. Flavonoid glycosides and ellagic acid cognates from defatted African mango (Irvingia gabonensis) seed kernel. Nat Prod Res. 2023;37(17):2878-2887. PubMed PMID: 36318869
22. Li J, Pan L, Naman CB, Deng Y, Chai H, Keller WJ, Kinghorn AD. Pyrrole alkaloids with potential cancer chemopreventive activity isolated from a goji berry-contaminated commercial sample of African mango. J Agric Food Chem. 2014;62(22):5054-60. PubMed PMID: 24792835

PubMed Topic Searches

1. PubMed: Irvingia gabonensis and body weight
2. PubMed: Irvingia gabonensis and blood lipids
3. PubMed: dika nut
4. PubMed: ogbono
5. PubMed: Irvingia gabonensis safety and toxicity

Connections

• Heart, Liver and Metabolic Herbs — the category hub for this page
• Cissus Benefits Deep Dive — the other plant in the 2008 combination trial
• Cissus Weight and Metabolic Trials — the combination trial read from the Cissus side
• Garcinia Cambogia — another fruit-derived weight-loss supplement
• Coleus forskohlii (Forskolin) — a further weight-loss herb with small trials
• Bitter Orange — weight-loss claims and heart safety
• Gymnema — a blood-sugar herb from the same hub
• Obesity — the condition the trials studied
• Lipid Panel — the cholesterol tests the trials measured
• Mango — the common mango, a different tree

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