Morosil is everywhere: in weight loss capsules at pharmacies, on social media, in before-and-after testimonials. A blood orange extract from Sicily that supposedly melts abdominal fat, backed by clinical studies. We don't sell it, and that's a good position to discuss it: we have nothing to defend, and nothing to tear down.
This guide reports exactly what research has published: the two randomized trials on the extract, what they measure and what they're worth; the two trials on blood orange juice, which find nothing; the case of severe hepatitis published in 2023; and what it's reasonable to expect from a plant extract on the scale.
Two randomized trials, both positive. Twelve weeks at 400 mg per day in 2015: BMI, weight, waist and hip circumference significantly better than placebo, without figures in the abstract. Six months in 2022: 4.2% weight loss versus 2.2%, 3.9 cm waist reduction versus 1.7, body fat and visceral fat down, normal liver. Two percentage points, or about 1.7 kg for 85 kg, in addition to diet and activity: a real and modest effect.
The limitations. Both trials are linked to the University of Catania, where the extract is produced; no independent team has replicated the results. Blood orange juice, meanwhile, has no effect on weight or lipids in two trials. A case of fulminant hepatitis with transplant was published in 2023, without proof of causation, but which requires caution. And placebo lost 2.2%: the context does most of the work.
What Morosil Is
The Moro orange is a variety of blood orange cultivated in eastern Sicily, on the slopes of Mount Etna, whose dark red flesh owes its color to anthocyanins, including cyanidin-3-glucoside, which it contains in unusually high quantities for a citrus fruit. Morosil is the dry extract of its juice, standardized in anthocyanins, produced by a Sicilian manufacturer and sold as a trademark to supplement laboratories. The studied dose is 400 mg per day.
The hypothesis is that these anthocyanins act on fat accumulation through antioxidant, anti-inflammatory, and metabolic pathways, which studies on cells and rodents have described. In humans, two randomized trials have been published.
The first trial: 12 weeks, Catania
In this clinical trial, the effect of supplementation with Moro orange juice extract, Morosil, 400 mg per day, was evaluated in overweight and healthy volunteers for 12 weeks. The results show that taking the extract induced a significant reduction in body mass index after 4 weeks of treatment. Furthermore, in subjects treated with the extract, body weight, BMI, waist circumference, and hip circumference were significantly different from those in the placebo group. The authors suggest that the active compounds in Moro orange juice have a synergistic effect on fat accumulation and that the extract can be used in weight management and obesity prevention.
Cardile V, Graziano ACE, Venditti A. Nat Prod Res 2015;29(23):2256-2260. DOI: 10.1080/14786419.2014.1000897
A trial positive on all its criteria, and an abstract that provides neither the number of participants nor the magnitude of differences, which is rare for a clinical trial and forces one to seek the full text to judge. The three authors are at the University of Catania, the city where the extract manufacturer is located. This is not fraud, it is proximity, and it counts in the reading.
The second trial: 6 months, Nutrients
In this randomized, double-blind, placebo-controlled study, all participants, overweight adults aged 20 to 65, were randomly assigned to receive either the standardized Moro blood orange extract or a placebo daily for six months. The primary endpoint was the change in body mass and composition at the end of the study. After six months, body mass, 4.2 versus 2.2 percent, body mass index, hip circumference, 3.4 cm versus 2.0 cm, and waist circumference, 3.9 cm versus 1.7 cm, fat mass and fat distribution, visceral and subcutaneous, were all significantly better in the extract group than under placebo. All markers of liver toxicity remained within normal ranges throughout the study in both groups. The authors conclude that the extract can be a safe and effective option to aid weight loss when used in combination with diet and exercise.
Briskey D, Malfa GA, Rao A. Nutrients 2022;14(3):427. DOI: 10.3390/nu14030427
This is the trial that drives Morosil sales, and it is better constructed than the first: six months, double-blind, figures, and liver monitoring. It is signed by an Australian clinical research company and by a researcher from the University of Catania. It says clearly what it says: with a diet and exercise, the extract performs a little better than placebo. It remains to see how much.
What These Figures Mean
| Criterion at 6 months | Extract | Placebo | Difference |
|---|---|---|---|
| Weight | - 4.2% | - 2.2% | 2 points, or approximately 1.7 kg for 85 kg |
| Waist circumference | - 3.9 cm | - 1.7 cm | 2.2 cm |
| Hip circumference | - 3.4 cm | - 2.0 cm | 1.4 cm |
| Body fat mass, visceral fat | Decreased | Less | Significant, figures not provided in the summary |
| Liver markers | Normal | Normal | None |
The effect is real : it is statistically significant on all criteria, in a six-month double-blind trial. It is also modest : two percentage points of weight loss is 1.5 to 2 kg more than placebo over six months for most adults, and 2 cm of waist circumference. And it is conditional : both groups followed a diet and exercised, and the placebo group lost 2.2% of its weight on its own. The framework did the essential work; the extract added a supplement. This is exactly what we expect from a plant extract that works, and it is far from a fat burner.
Blood orange juice does nothing
Two teams tested the juice rather than the extract. The Italian Council for Agricultural Research gave 500 ml per day of commercial blood orange juice to 11 obese women for 12 weeks: no effect on weight, a decrease in total and LDL cholesterol, and a straightforward conclusion, the data do not support the idea that this juice prevents obesity or its metabolic disorders. Quadram Institute in England compared in 41 adults with elevated waist circumference 500 ml of blood orange juice, 50 mg of anthocyanins per day, and 500 ml of blonde orange juice, for 28 days: no difference in LDL, blood sugar, blood pressure, or arterial stiffness.
Juice is not extract: 500 ml of juice provides 50 mg of anthocyanins and lots of sugar, whereas the extract concentrates the anthocyanins without the sugar. These trials therefore do not directly contradict those on Morosil. They say two useful things: drinking blood orange juice does not cause weight loss, and the effect, if it exists, depends on concentration. They also remind us that independent teams testing blood orange find nothing, when teams linked to the extract find something.
The 2023 case and safety
We report the case of a 37-year-old female patient admitted for grade 4 hepatic encephalopathy. Morosil intake had begun 30 days prior and, after two weeks, jaundice and transit disorders appeared, after which the product was discontinued. Morosil is a dry extract of Moro red orange juice grown in eastern Sicily, an important source of anthocyanidins. The diagnosis of acute liver failure was confirmed according to Clichy and King's College criteria. The patient was placed on the priority list for liver transplantation, with a MELD score of 41, and the transplant was performed without complications. There are few reports of acute liver damage with other citrus fruits, and we found no reported cases of acute liver failure linked to Morosil.
Fernandes DP, De Ataide EC, Perales SR, et al. Transplant Proc 2023;55(6):1454-1456. DOI: 10.1016/j.transproceed.2023.04.014
A single case does not prove that Morosil caused hepatitis: idiosyncratic liver injury can have other origins, and the six-month trial showed no liver abnormalities in its participants. It says nothing about frequency either, which is probably very low relative to the number of people taking it. But it is published by a transplant unit, the timeline is compatible, and this is the first time such a case has been described. It justifies a rule that applies to any supplement: unusual fatigue, dark urine, jaundice, stop and consult a doctor. And in case of known liver disease, do not start without medical advice.
1.44 g of konjac per day in three capsules, with a large glass of water before meals. Its fiber, glucomannan, absorbs water and swells in the stomach: a volume mechanism that accompanies a lighter meal, without acting on metabolism. What the Morosil trial reminds us is that the framework—diet and activity—does the essential work; konjac is a tool to maintain that framework.
View Pure KonjacAlways with plenty of water. Not suitable if you have difficulty swallowing. Our appetite suppressant guide compares active ingredients that have been tested.
Frequently asked questions
What is Morosil?
A dry extract of blood orange juice from the Moro variety, cultivated in eastern Sicily around Mount Etna, standardized in anthocyanins, the red pigments of the fruit, including cyanidin-3-glucoside. It is a registered trademark, produced by a Sicilian manufacturer, and the studied dose is 400 mg per day. It has established itself in recent years as the best-selling ingredient in weight loss supplements, driven by two positive randomized trials.
What does the first trial show?
The trial published in 2015 in Natural Product Research by the University of Catania gave 400 mg per day of Morosil or placebo for 12 weeks to overweight, healthy volunteers. Body mass index was significantly reduced as early as the fourth week, and weight, BMI, waist circumference, and hip circumference differed significantly from the placebo group at the end. The abstract provides neither the sample size nor the magnitude of differences, and the authors are from Catania, the city where the extract is produced.
What does the second trial show?
The trial published in 2022 in Nutrients, randomized double-blind against placebo, followed overweight adults aged 20 to 65 years, in good health, taking the standardized extract or placebo for six months. At six months, the extract group had lost 4.2% of body weight versus 2.2% under placebo, 3.9 cm of waist circumference versus 1.7, 3.4 cm of hip circumference versus 2.0, with significantly greater reductions in fat mass and visceral fat. Liver markers remained normal in both groups. The authors conclude that the extract can help with weight loss as a complement to diet and physical activity.
Are these results significant?
They are real and modest. Two percentage points of weight over six months is approximately 1.7 kg more than placebo for an 85 kg person, and 2.2 cm more waist circumference. The placebo group also lost 2.2%, which shows that the trial framework—diet and activity—did the essential work. It is an ancillary effect, consistent with what we expect from a plant extract, and far removed from the promises seen on some packaging.
Why are studies on blood orange juice negative?
Two trials tested the juice itself. In 11 obese women, 500 ml of blood orange juice per day for 12 weeks did not change weight, only cholesterol. In 41 adults with elevated waist circumference, 500 ml per day providing 50 mg of anthocyanins for 28 days changed neither LDL, blood sugar, nor blood pressure compared to blonde orange juice. Juice is not extract: it provides few anthocyanins and much sugar. These trials do not directly contradict those on the extract, but they remind us that the effect, if it exists, depends on concentration, and that drinking blood orange juice does not cause weight loss.
Is Morosil dangerous for the liver?
A case was published in 2023 in Transplantation Proceedings : a 37-year-old woman, hospitalized in Brazil for grade 4 hepatic encephalopathy, had started Morosil thirty days earlier and developed jaundice after two weeks. Acute liver failure was confirmed and she received a liver transplant. The authors found no other reported case with Morosil, and a few cases with other citrus fruits. A single case does not prove causality and says nothing about frequency; both trials showed no liver abnormalities. But it justifies a simple rule: if you experience unusual fatigue, dark urine, or jaundice while taking a supplement, stop and consult a doctor.
Who funded these trials?
The first trial is signed by the University of Catania, in Sicily, where the extract is produced. The second involves an Australian clinical research company and a researcher from the same University of Catania. This is not disqualifying; most trials on patented ingredients are funded or co-signed by their manufacturer, but it means that no independent team has replicated these results to date. This is the main limitation of the evidence.
What to remember about Morosil?
That two randomized trials show a real and modest effect, approximately two percentage points of weight over six months in addition to diet and activity, or 1.5 to 2 kg. That both are linked to the city where the extract is produced and that no independent replication exists. That blood orange juice itself does nothing for weight. That a case of severe hepatitis was published, without proof of causality but which demands vigilance. And that the framework—diet and activity—does the essential work: placebo lost 2.2%.
Sources
The studies cited below were identified via PubMed.
- Cardile V, Graziano ACE, Venditti A. Clinical evaluation of Moro orange juice extract supplementation for weight management. Natural Product Research, 2015;29(23):2256-2260. DOI
- Briskey D, Malfa GA, Rao A. Efficacy of a standardized Moro blood orange extract on weight loss in overweight but healthy men and women: a randomized, double-blind, placebo-controlled trial. Nutrients, 2022;14(3):427. DOI
- Azzini E, Venneria E, Ciarapica D, et al. Effect of red orange juice consumption on body composition and nutritional status in overweight or obese women: a pilot study. Oxidative Medicine and Cellular Longevity, 2017;2017:1672567. DOI
- Hollands WJ, Armah CN, Doleman JF, Perez-Moral N, Winterbone MS, Kroon PA. Four weeks of anthocyanin-rich blood orange juice consumption does not modify LDL cholesterol or other cardiovascular risk markers and glycemic markers compared to standard orange juice: a randomized controlled trial. British Journal of Nutrition, 2018;119(4):415-421. DOI
- Fernandes DP, De Ataide EC, Perales SR, et al. Acute liver failure secondary to anthocyanidin use: a clinical case. Transplantation Proceedings, 2023;55(6):1454-1456. DOI
