Benefits
Body weight and fat mass loss alongside diet
Across three small randomized trials pooled in one analysis (252 adults), Moro orange extract was linked to about 2 kg more weight loss (95% CI 0.67 to 3.50 kg) and 1.5 kg more fat loss than placebo, with no effect on lean mass. The trials were small and the largest was maker-funded, so treat this as a possible add-on to diet and exercise, not a standalone fat burner.
Waist and hip circumference
In the 6-month trial, waist shrank 3.9 cm versus 1.7 cm on placebo and hip 3.4 cm versus 2.0 cm. The 12-week trial also reported waist and hip differences from placebo. When the trials were pooled, though, waist results disagreed almost completely between studies (I-squared 99%, p=0.05), so the waist effect is not settled.
Visceral and subcutaneous body fat
In the 6-month trial, body scans showed that visceral fat (around the organs) and subcutaneous fat (under the skin) fell more on the extract than on placebo (p=0.018 and p=0.006). This comes from one maker-funded trial in which everyone was also dieting, and the pooled analysis did not report visceral fat, so it has not been confirmed.
Anthocyanin antioxidant content
Moro is the most deeply pigmented blood orange variety, with juice averaging about 140 mg of anthocyanins per liter, mainly cyanidin 3-glucoside. The extract used in the 6-month trial contained 0.635% cyanidin 3-glucoside and 4.5% vitamin C. This describes what is in the product; the Morosil trials measured body size and composition, not antioxidant status.
Mechanism of action
Inhibits adipogenesis
In lab dishes, not in people, Morosil slowed the maturing of 3T3-L1 mouse fat-cell precursors into fat cells, lowering fat storage, the activity of fat-making genes and oxidative stress in the cells. Whether any of this happens in the human body is unknown.
PPAR-α activation and lipid homeostasis
In mice fed a high-fat diet for 12 weeks, Moro juice limited fat build-up in the liver by switching on PPAR-alpha and its target enzyme acyl-CoA oxidase, a key enzyme for burning fat, while switching off liver X receptor-alpha and the fat-making enzyme fatty acid synthase. This is an animal finding and has not been shown in people.
Anthocyanin-mediated metabolic modulation
Cyanidin 3-glucoside is thought to act on antioxidant, anti-inflammatory and metabolic pathways. In mice on a high-fat diet, Moro juice limited weight gain, improved insulin sensitivity and lowered triglycerides and total cholesterol. In the 6-month human trial, blood glucose, insulin and lipid measures did not change in either group.
Clinical trials
Single-site, randomized, double-blind, placebo-controlled trial in Brisbane, Australia, of 400 mg a day of Morosil for 6 months alongside a calorie-controlled diet and exercise. Funded by Bionap, which also supplied the capsules (Briskey et al. 2022, Nutrients)
180 overweight but otherwise healthy adults aged 20 to 65 were randomized; 136 completed baseline and were analyzed (65 on Morosil, 71 on placebo) and 98 finished all 6 months.
After 6 months, body weight fell 4.2% versus 2.2% on placebo (p=0.015), with greater drops in BMI (p=0.019), waist (3.9 vs 1.7 cm), hip (3.4 vs 2.0 cm), fat mass (p=0.012) and visceral and subcutaneous fat. Weight differed significantly between groups at months 4 and 6. Liver markers stayed normal and glucose, insulin and lipids did not change. Two people on Morosil and five on placebo reported side effects such as nausea or constipation.
Placebo-controlled trial of 400 mg a day of Morosil for 12 weeks in overweight healthy volunteers. The abstract does not give the number of participants or the funding source; the later 6-month trial report describes it as 60 adults (Cardile et al. 2015, Nat Prod Res)
Overweight healthy volunteers; 60 adults according to the later 6-month trial report.
BMI fell significantly after 4 weeks on Morosil, and at 12 weeks body weight, BMI, waist and hip circumference differed significantly from the placebo group (p<0.05). The abstract gives no effect sizes, and with about 60 people over 12 weeks the trial is too small to settle the question on its own.
Systematic review and meta-analysis of randomized, placebo-controlled trials of Moro orange juice extract, searching PubMed, Embase and Cochrane (Campos et al. 2026, Nutr Health)
3 randomized trials with 252 overweight or obese adults in total.
Body weight fell 2.08 kg more than placebo (95% CI -3.50 to -0.67, I-squared 0%) and fat mass 1.53 kg more (95% CI -2.92 to -0.15, p=0.03). Waist results varied widely between trials (-3.25 cm, 95% CI -6.44 to -0.07, I-squared 99%, p=0.05). Lean mass did not change. BMI was a primary outcome, but the abstract gives no pooled BMI result. The authors call for more research on dose and duration.