Written by Shereen, Product Management Associate · Updated 11 November 2026
What is Sinetrol, and does grapefruit extract help burn fat?
Sinetrol® is a citrus polyphenol extract made from grapefruit and orange, combined with guarana. In placebo-controlled trials, adults with overweight or obesity who took it every day for 12 to 16 weeks lost more body fat than those on placebo. The trials tested the whole blend, not grapefruit on its own.
This article is for you if: you've seen Sinetrol® or grapefruit extract on a slimming drink label and want to know what's in it, what the human trials found, and how it fits into your day in Singapore.
Grapefruit extract appears on many slimming drink labels. Sinetrol® is a blend of citrus and guarana extracts that has been tested in placebo-controlled trials in people. Here's what's in it, what each trial found, how it might work, and how to fit it into your day.
→ See Grapefruit & Kombucha Slimming Blend, our daily citrus drink with 630 mg of Sinetrol®
In this article
What is in Sinetrol?
Sinetrol® is a polyphenol extract from citrus fruits, with guarana as a natural source of caffeine.[2]
- The original Sinetrol® was described in 2008 as a polyphenolic dry extract of red orange, grapefruit and orange.[1]
- Sinetrol® Xpur, the version used in the more recent trials, is rich in flavanones from grapefruit, pomelo, sweet orange and blood orange, with caffeine from guarana extract.[2]
- Citrus flavanones such as naringenin and hesperidin have shown effects on blood sugar and blood fats in lab studies.[2]
In our Grapefruit & Kombucha Slimming Blend, the Sinetrol® is made from grapefruit, orange and guarana extracts. Each 12 g scoop has 630 mg of it, with about 22 mg of natural caffeine.
What did the human trials on Sinetrol find?
In the two larger placebo-controlled trials, adults taking Sinetrol® lost more body fat than people on placebo, and in the Korean trial, more body weight too.
| Study | Who took part | Daily dose and length | Main result |
|---|---|---|---|
| Dallas et al., 2008 | 20 adults with overweight (two groups of 10) | 1.4 g Sinetrol® or placebo, 12 weeks | Body fat percentage and body weight fell significantly in the Sinetrol® group at 4 and 12 weeks |
| Cases et al., 2015 | Men with overweight (pilot trial) | 900 mg Sinetrol® Xpur, 12 weeks | Slimmer silhouette, better metabolic markers and less muscle breakdown |
| Park et al., 2020 | 100 Korean adults with overweight or obesity (86 finished) | 900 mg Sinetrol® Xpur or placebo, 12 weeks | Body weight, BMI and body fat mass all fell more than with placebo |
| Muralidharan et al., 2026 | 77 adults with overweight or obesity | 900 mg Sinetrol® Xpur or placebo, 16 weeks | Total body fat percentage down 1.98% compared with placebo |
Sources: the published trials listed in the References.[1] [3] [4] [5]
The 16-week trial is a useful real-life test. Participants ate a normal-calorie diet and kept their usual activity levels. Alongside the fat loss, there was a trend towards more lean mass than placebo, and resting energy expenditure, the energy your body uses at rest, rose in the Sinetrol® group.[5]
Safety was checked too: in the 16-week trial, all safety measures stayed within normal ranges and no adverse effects were noted,[5] and in the Korean trial, safety results were similar in the Sinetrol® and placebo groups.[4]
How might Sinetrol work?
The leading idea is that Sinetrol® helps fat cells release stored fat. In human fat cells in the lab, it raised the release of fatty acids about sixfold compared with control cells, and was 2.1 times as active as a guarana extract with 12% caffeine while containing a third as much caffeine. The researchers linked this to strong inhibition (97%) of an enzyme called cAMP-phosphodiesterase.[1]
Other pathways are being studied too:
- Energy use. Caffeine and citrus flavonoids may raise energy expenditure, through the same enzyme and by stimulating beta-2 adrenergic receptors.[2]
- Gut bacteria. In a 16-week study of 20 adults taking 900 mg or 1,800 mg a day, HDL and LDL cholesterol and HbA1c (a marker of average blood sugar) improved at either dose, gut bacteria shifted towards butyrate producers, and visceral fat showed a downward trend.[2]
Where does Sinetrol fit in your day?
Sinetrol® fits best as a daily habit, taken early in the day. Our Grapefruit & Kombucha Slimming Blend and Lemon & Kombucha Slimming Blend each contain 630 mg of Sinetrol® grapefruit, orange and guarana extracts per 12 g scoop. Each blend also has 500 mg of L-arabinose, 400 mg of konjac and 7,000 mg of isomalto-oligosaccharide, a prebiotic fibre. Grapefruit & Kombucha Slimming Blend is halal-certified by JAKIM, the Department of Islamic Development Malaysia.
- Stir 1 scoop into 300 to 350 ml of water.
- Have it before breakfast or lunch. Morning or midday also suits its natural caffeine. If you're sensitive to caffeine, see how caffeine affects your cycle and your sleep.
- Keep it consistent. The trials ran for 12 to 16 weeks, so judge progress over months, not days.
We advise anyone taking statins to check with a practitioner before using either blend, because both contain grapefruit extract, and grapefruit has the potential to interact with more than 85 medicines.[6] If you take regular medication, or you're pregnant or breastfeeding, check with your doctor first.
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Related reading: Do The Purest Co slimming drinks have side effects? · Does blood orange extract help with weight management? · Does L-carnitine help you lose weight?
Frequently asked questions
Does Sinetrol contain caffeine?
Yes. Sinetrol® includes guarana, a natural source of caffeine, and each scoop of Grapefruit & Kombucha Slimming Blend has about 22 mg of natural caffeine. If you're sensitive to caffeine, pregnant or breastfeeding, check with your doctor before using it, and count it towards your daily coffee and tea.
Can I take grapefruit extract with medication?
Check first. More than 85 medicines have the potential to interact with grapefruit, through natural compounds called furanocoumarins. If you take any regular medication, ask your doctor or pharmacist before starting a grapefruit-based supplement.
Is Sinetrol safe?
In the 16-week trial, all safety measures stayed within normal ranges and no adverse effects were noted. In the Korean trial, safety results were similar in the Sinetrol® and placebo groups. As with any supplement, follow the label and check with your doctor if you have a health condition.
Do you need to diet for Sinetrol to work?
In the 16-week trial, people ate a normal-calorie diet and kept their usual activity, and the Sinetrol® group still lost more body fat than the placebo group. You don't need a crash diet. Balanced meals, fewer sugary drinks and regular movement are still the best base to build on.
Is drinking grapefruit juice the same as taking Sinetrol?
No. The trials tested an extract of citrus and guarana at a set daily amount, not fresh fruit or juice. Whole grapefruit is still a refreshing fruit choice, and an extract gives you the same measured amount every day.
Key takeaways
- Sinetrol® is an extract of citrus polyphenols from grapefruit and orange, with guarana as a natural source of caffeine.
- In placebo-controlled trials of 12 to 16 weeks, adults with overweight or obesity who took Sinetrol® lost more body fat than those on placebo.
- In the 16-week trial, people ate a normal-calorie diet and kept their usual activity, and all safety measures stayed within normal ranges.
- Lab research suggests it helps fat cells release stored fat.
- Grapefruit & Kombucha Slimming Blend and Lemon & Kombucha Slimming Blend each have 630 mg of Sinetrol® per scoop. Check with your doctor first if you take regular medication.
About the author: Shereen is a Product Management Associate at The Purest Co. A Master's graduate in Pharmacy from Monash University, she brings four years of research experience to product development, with a focus on evidence-based, thoughtfully formulated supplements that support everyday wellbeing.
References
[1] Dallas C, Gerbi A, Tenca G, Juchaux F, Bernard FX. Lipolytic effect of a polyphenolic citrus dry extract of red orange, grapefruit, orange (SINETROL) in human body fat adipocytes. Mechanism of action by inhibition of cAMP-phosphodiesterase (PDE). Phytomedicine. 2008.
[2] Muralidharan J et al. Effect of Sinetrol® Xpur on metabolic health and adiposity by interactions with gut microbiota: a randomized, open label, dose-response clinical trial. Nutr Metab (Lond). 2024.
[3] Cases J, Romain C, Dallas C, Gerbi A, Rouanet JM. A 12-week randomized double-blind parallel pilot trial of Sinetrol XPur on body weight, abdominal fat, waist circumference, and muscle metabolism in overweight men. Int J Food Sci Nutr. 2015.
[4] Park SJ et al. Efficacy and safety of Sinetrol-XPur on weight and body fat reduction in overweight or obese adults: a 12-week, randomized, double-blind, parallel, placebo-controlled trial. J Med Food. 2020.
[5] Muralidharan J et al. A 16-week supplementation with a polyphenol-rich supplement, Sinetrol® Xpur, aids in fat loss of overweight and obese volunteers: a randomised, double-blind, parallel trial. Int J Food Sci Nutr. 2026 (published online 2025).
[6] Bailey DG, Dresser G, Arnold JM. Grapefruit-medication interactions: forbidden fruit or avoidable consequences? CMAJ. 2013.
These statements have not been evaluated by any regulatory authority. This product is not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary. Consult a healthcare provider before use if you are pregnant, breastfeeding, or on prescribed medication.