Grape Juice Concentrate
Also known as: GJC, red grape juice concentrate, G8000, Vitis vinifera juice concentrate
Effective Dosage
No established dose (insufficient research data)
What the Science Says
Grape juice concentrate is a polyphenol-rich extract made from grapes, containing flavonoids and other antioxidant compounds. In animal studies, it has shown the ability to reduce oxidative stress, protect reproductive organs and liver tissue from toxic damage (specifically cadmium poisoning), reduce inflammatory markers like COX-2 and TNF-alpha, and show some anti-tumor activity in chemically induced cancer models. All of these findings come exclusively from rat studies, so it is unknown whether these effects translate to humans.
What It Doesn't Do
Not proven to protect humans from heavy metal poisoning. No human trials show it prevents cancer. No evidence it improves fertility in people. Don't assume rat study results mean anything for your body yet. Not a detox supplement with proven human data.
Evidence-Based Benefits
In rat models, grape juice concentrate (GJC) demonstrated antioxidant, anti-inflammatory, and cytoprotective effects, particularly against cadmium-induced damage to the testes, epididymis, and liver (PMIDs: 23656754, 28581201, 27056637). GJC reduced lipid peroxidation, DNA damage, and pro-inflammatory markers (COX-2, TNF-α) in rodent tissues exposed to chemical toxicants (PMIDs: 24996944, 24401099, 26492449). It also showed anti-inflammatory effects in a rat model of TNBS-induced colitis, reducing macroscopic and histological damage scores at a 1% dose (PMID: 23517616).
Weak EvidenceEffective at: No established dose (insufficient research data)
Source: auto-research
Absorption & Bioavailability
Unknown — no human pharmacokinetic data in the provided studies. Rat studies used oral gavage administration, but absorption and bioavailability in humans has not been assessed in the provided research.
Red Flags to Watch For
- All available research is in rats only — zero human clinical trials in the provided data
- Rat doses (1.18–2.36 g/kg/day) do not translate directly to human dosing and may not be safe or practical
- Widely used in supplements (1000+ registered products) despite no human efficacy data
- Anti-cancer and fertility claims based entirely on chemically induced animal disease models, which often don't replicate human conditions
- One indexed paper is about wine spoilage yeast and is completely irrelevant to human health benefits
Products Containing Grape Juice Concentrate
See how Grape Juice Concentrate is used in these analyzed products:
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-04-06