Grapefruit Extract
Research reviewed: Up until 03/2026
Grapefruit Extract (Citrus paradisi (Naringenin / Naringin)) is a dietary supplement with 9 published peer-reviewed studies involving 179 participants, researched for Weight & Metabolic Health, Cholesterol & Anti-inflammatory.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Weight & Metabolic Health
ModerateCholesterol & Anti-inflammatory
ModerateResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Weight & Metabolic Health
Fresh grapefruit, grapefruit juice, and capsules for weight loss and insulin resistance
Study Type
RCT
Purpose
Fresh grapefruit, grapefruit juice, and capsules for weight loss and insulin resistance
Dose
Half fresh grapefruit or 8oz juice before each meal
Participants
91 obese adults
Duration
12 weeks
Results
All grapefruit groups lost significantly more weight than placebo. Fresh grapefruit group lost 1.6 kg vs 0.3 kg. Grapefruit significantly improved insulin resistance.
How They Measured It
Body weight, BMI, insulin resistance, lipid profile
Naringenin effects on insulin sensitivity and metabolic rate
Study Type
Metabolic rate case study
Purpose
Naringenin effects on insulin sensitivity and metabolic rate
Dose
Naringenin equivalent (3 grapefruits/day)
Participants
Case study and mechanistic analysis
Duration
8 weeks
Results
Naringenin supplementation increased metabolic rate and insulin sensitivity without adverse events. Beta-3 adrenergic receptor stimulation mechanism identified.
How They Measured It
RMR, glucose uptake, insulin sensitivity markers
Cholesterol & Anti-inflammatory
Lipolytic effect of polyphenolic citrus extract containing grapefruit compounds via cAMP-PDE inhibition
Study Type
Lipolytic mechanism study
Purpose
Lipolytic effect of polyphenolic citrus extract containing grapefruit compounds via cAMP-PDE inhibition
Dose
Citrus polyphenol extract
Participants
Human adipocyte cells
Duration
N/A
Results
Citrus polyphenol extract including naringenin demonstrated lipolytic effect via cAMP-PDE inhibition in human adipocytes. Supports fat mobilisation mechanism.
How They Measured It
cAMP-phosphodiesterase inhibition, lipolysis rates in adipocytes
Naringenin effects on hepatic lipid metabolism via PPAR activation
Study Type
Hepatic lipid metabolism study
Purpose
Naringenin effects on hepatic lipid metabolism via PPAR activation
Dose
Various naringenin concentrations
Participants
Human and rat hepatocytes
Duration
N/A
Results
Significantly regulated lipid metabolism via PPAR activation, reducing triglyceride accumulation and increasing fatty acid oxidation. Mechanism relevant to NAFLD treatment.
How They Measured It
PPARalpha/gamma expression, triglyceride synthesis, lipid oxidation
Effects of naringin and naringenin on metabolic syndrome
Study Type
Review of metabolic syndrome effects
Purpose
Effects of naringin and naringenin on metabolic syndrome
Dose
Various
Participants
Review
Duration
Various
Results
Citrus flavonoids reduce obesity, dyslipidaemia, hyperglycaemia, and hypertension via AMPK activation, PPARalpha/gamma agonism, and anti-inflammatory pathways.
How They Measured It
Systematic review
Grapefruit consumption on cardiovascular risk markers in patients on lipid medication
Study Type
Cardiovascular RCT
Purpose
Grapefruit consumption on cardiovascular risk markers in patients on lipid medication
Dose
One fresh grapefruit daily
Participants
57 patients on lipid-lowering medication
Duration
30 days
Results
Significantly reduced total cholesterol, systolic blood pressure, and oxidative stress. Red grapefruit showed greatest antioxidant activity due to lycopene content.
How They Measured It
Blood pressure, arterial stiffness, serum lipids, oxidative stress
Naringenin anti-inflammatory effects via NF-kB pathway in macrophages
Study Type
Anti-inflammatory study
Purpose
Naringenin anti-inflammatory effects via NF-kB pathway in macrophages
Dose
Naringenin 10-100µM
Participants
LPS-stimulated macrophages
Duration
N/A
Results
Potently inhibited NF-kB and downstream inflammatory mediators. Anti-inflammatory potency comparable to ibuprofen in COX-2 inhibition assay.
How They Measured It
NF-kB activation, COX-2, TNF-alpha, IL-1beta
Naringenin effects on LXRalpha and foam cell formation in macrophages
Study Type
LXRalpha macrophage study
Purpose
Naringenin effects on LXRalpha and foam cell formation in macrophages
Dose
Naringenin 50µM
Participants
THP-1 macrophages
Duration
N/A
Results
Significantly increased LXRalpha expression and promoted cholesterol efflux from macrophages, reducing foam cell formation. Anti-atherogenic mechanism at cellular level.
How They Measured It
LXRalpha expression, cholesterol efflux, foam cell formation
Grapefruit juice interactions with statin medications for safety
Study Type
Statin interaction study
Purpose
Grapefruit juice interactions with statin medications for safety
Dose
200ml grapefruit juice daily
Participants
30 statin therapy patients
Duration
5 days
Results
Significantly increased plasma concentrations of CYP3A4-metabolised statins. Important safety finding: avoid with simvastatin/lovastatin, but safe with pravastatin.
How They Measured It
Statin plasma levels, AUC, Cmax, adverse effects
Frequently Asked Questions
Common questions about Grapefruit Extract research
There are currently 9 peer-reviewed studies on Grapefruit Extract (Citrus paradisi (Naringenin / Naringin)), involving 179 total participants. Research covers Weight management & body composition, Cholesterol & cardiovascular, Insulin sensitivity & blood sugar and 1 more areas. The overall evidence strength is rated as Moderate.
The evidence is currently rated as "Moderate Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (4 human studies), and reported outcomes.
Grapefruit Extract has been researched for: Weight management & body composition, Cholesterol & cardiovascular, Insulin sensitivity & blood sugar, Antioxidant & anti-inflammatory. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 4 out of 9 studies are human trials. Human trials carry more weight in our evidence scoring system.
