Ingredient evidence
Green tea extract blood sugar: what reviews found and what to watch
Green tea extract blood sugar results were null in one review of 6 trials with 382 people who had prediabetes or type 2 diabetes: no difference in HbA1c or fasting glucose. LiverTox also reports rare liver injury cases. Olivaro lists green tea leaf extract with no amount and no caffeine figure.
Written by the Olivaro label deskUpdated · 5 min read
The evidence
Does green tea extract affect blood sugar?
In the best-matched review we read, it made no measurable difference. Six randomized trials with 382 people who had prediabetes or type 2 diabetes found no change in HbA1c or fasting glucose (Yu 2017, green tea glycemic meta).
The same paper mentions an earlier review of 17 trials that found small falls, so results are not uniform. Doses and trial lengths are not in the abstract we read, and no trial tested Olivaro. ADA's 2026 Standards of Care do not recommend herbs for glycemic benefit (ADA 2026, Standards of Care, supplements).
Liver safety
Is green tea extract safe for the liver?
We cannot call any extract safe for everyone. LiverTox collects case reports of liver injury linked to green tea extract, and notes an association with a gene variant, HLA-B*35:01 (LiverTox, green tea).
These are reports, not a rate, and nothing shows Olivaro was involved. The label prints no green tea amount. Stop and get care for dark urine, yellow skin or eyes, or belly pain. People with liver disease should ask a clinician first. Gymnema in the same blend has a similar liver note, so the liver line applies to the whole list.
Caffeine
Does green tea extract add caffeine?
Green tea leaf is a caffeine source, and so is guarana, which is listed beside it in Olivaro's blend. The label prints no caffeine amount, so we cannot say how much caffeine a serving holds.
| Item | Fact |
|---|---|
| Guarana seed extract | Seeds hold up to 6% caffeine (Schimpl 2013, guarana review) |
| Green tea leaf extract | In the blend; no amount printed |
| Reference level | 400 mg a day for most healthy adults (FDA, Spilling the Beans caffeine) |
The 400 mg figure is a reference, not a dose in the bottle. Ask about evening use, sleep trouble, anxiety or heart rhythm.
Olivaro liquid: 30 mL a bottle1 mL serving · 2, 3 or 6 bottles · from $49 a bottle · shipping at checkout
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How well do human studies support the other blend ingredients?
The gauges below are an editor's reading of human studies, not a measurement and not a rating of Olivaro.
Chromium
Little22 of 100
NIH says the effect on glucose in people with diabetes is small and its significance unclear; the label's 0.7 mcg is 2% of the Daily Value. (NIH ODS, Chromium) (Zhao 2022, chromium type 2 diabetes meta)
Gymnema
Little18 of 100
Small, mixed studies at amounts far above anything the 200 mg blend could hold for one ingredient. (Devangan 2021, gymnema type 2 diabetes meta) (LiverTox, Gymnema)
Green tea and guarana
Little15 of 100
Trials of green tea show little glycemic effect; both are caffeine sources, and the label prints no amounts. (Yu 2017, green tea glycemic meta) (Schimpl 2013, guarana review)
Ginseng and herbs
Little15 of 100
Small trials of single herbs at studied amounts; none at the unstated amounts in this blend. (Shishtar 2014, ginseng glycemic meta) (Hong 2024, astragalus type 2 diabetes meta)
Amino acids
Very little5 of 100
No human trial found at the unstated amounts, so there is nothing to set the label beside. (Saldanha 2023, proprietary blends perspectives)
Our reading of the sources, not a measurement. Each needle is an editor's judgment of how well human studies support the label's blood sugar lines for that ingredient group, at studied amounts. It does not rate Olivaro: no study tested the liquid or this 22-ingredient blend.
Keep taking prescribed medicine; ask a clinician or pharmacist first if you take diabetes medicine. Severe low blood sugar (confusion, fainting, seizure), chest pain or trouble breathing: call 911. More is on the green tea and guarana page.
90-serving supply
3 bottles: 90 mL
$207$69 a bottle
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180-serving supply
6 bottles: 180 mL
$294$49 a bottle
Shipping at checkout · 60-day guarantee
See 6 bottlesSeller-listed prices; confirm at checkout (Olivaro sales site). Two bottles are also sold. If you take diabetes medicine or insulin, ask your clinician or pharmacist before you order.
FAQ
Olivaro questions people ask
Can green tea extract lower A1C?
In a review of 6 trials with 382 people who had prediabetes or type 2 diabetes, HbA1c did not differ. Doses are not in the abstract, and no trial tested Olivaro. Ask your clinician about A1C testing and care.
What are signs of a liver problem from a supplement?
Dark urine, yellow skin or eyes and belly pain. Stop the product and get care. LiverTox describes case reports for green tea extract, which are not a rate, and nothing shows Olivaro caused any.
Is there caffeine in Olivaro?
Guarana and green tea leaf are both caffeine sources in the blend, and the label prints no caffeine amount. Seeds of guarana hold up to 6% caffeine. Ask a clinician if you are sensitive to caffeine.
Who wrote this
Written and reviewed by
Pages built from the label, the seller's brief and linked NIH, FDA, CDC, FTC and peer-reviewed sources.
Last updated . Read our editorial standards and how we check reviews. This website is the information site of a USA Authorized Olivaro Retailer. It is not the manufacturer, and the label names Instituto Experience as the distributor. We earn money when you buy through our order links.
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