In our offices here at Phytoquant, Grapefruit Seed Extract (QuantaEPP) is at our desks at all times. Aside from helping us keep our immune system strong all year long, we also started using it to mix our own hand sanitizers. We're even using it to disinfect produce by adding 20 drops to a large bowl of water, stirring well, and letting the fruits and vegetables soak for 5-10 minutes.

This is a supplement you'll want to have as part of your routine. Here's why: 

GSE: Three Letters We Should All Know for Immune Health 

Grapefruit Seed Extract is Just What You Need


One of the more common mistakes in seeking immune health is the notion that a mere boost or supplement-on-the-spot will protect and shield you from harmful bacteria and viruses. Unfortunately, this quick fix mentality has been commercialized and it’s a detriment to actually improving your immunity.

Strengthening your immune system is one of the most important things you can do. It supports you during cold and flu season, lowers your risk of infections, and it cannot be rushed. 

Scientific and medical research continues to study fascinating herbs, elements, foods, and even things we’d traditionally discard that can actually transform our immune systems and increase our ability to live healthier lives. Grapefruit Seed Extract (GSE) is perhaps one of the most unique immune-strengthening elements being studied right now in laboratories and academia around the world. 

With remarkable antibacterial properties, GSE has been used to successfully combat Borrelia bacterium, which causes Lyme Disease, with positive results¹. And yes, grapefruits, the citrus we often cast aside for sweet oranges or bright lemons, are the true champions of the Rutaceae family. 

GSE is an exceptional antimicrobial - it can suppress and even destroy bacteria and fungi before they multiply. It goes to work almost immediately, whether ingested or used in topical applications, disrupting bacterial strains with precision. 

These phenomenal immunity-enhancing attributes are largely due to naringenin, one of the primary antioxidants found in GSE. Naringenin, like many other immunity-forward flavonoids, is a powerful phytonutrient that not only reduces inflammation but also increases metabolism.

A robust immune system that effectively fights a variety of infections is what we should all be striving for, and it is attainable. Ensuring the body is ready to battle bad bacteria, fungal infections and dangerous viruses requires maintenance and cannot be treated with one shot of vitamin C. 

However, vitamin C is important for all of us and GSE has naturally occurring vitamin C. It can even be used as an effective household cleaner. This combination of antibacterial, antifungal, and antiviral properties is why GSE, when tested in Europe, demonstrated the largest zones of effective inhibition for Listeria, one of the most serious bacterial infections from food contamination that primarily affects those with weakened immune systems². 

It’s the citrus fruit we tend to ignore, but its far-reaching properties make Grapefruit, and more importantly the extract from its seeds, a natural wonder.

Pure Grapefruit Seed Extract, found in PhytoQuant’s QuantaEPP, is essential to strengthening and maintaining year-round immune health.

If you have any questions, please reach out to us. We’re here to help, because we care.
Mon-Thurs/ 10 am ET – 4 pm ET

In case you missed it, check out Part II in our series on Gut Health and Immunity here.

Are you a Health Professional interested in learning more about our products and how we can work together? Please contact us at


¹ Brorson PDF
² EPP-GSE-24304 PDF   


These statements have not been evaluated by the Food and Drug Administration.
These products are not intended to diagnose, treat, cure, or prevent any disease.