Boosting Your Immune System with Olive Leaf Extract

Image: Barlean's Olive Leaf Complex soft gels, liquid and throat spray sitting on plate

When you think about how to boost your immune system, what’s the first herb that comes to mind? If you said Echinacea, you’re not alone. But olive leaf extract is quickly surging in popularity, giving Echinacea a run for its money.

The magic of oleuropein

Olive leaves contain a natural arsenal of protective polyphenols, most notably oleuropein. First isolated over 100 years ago, oleuropein improves immune function and offers powerful antioxidant protection.* Some people have even speculated that oleuropein may be the reason olive trees, which can live to be 1,000 years old, are so hardy and disease-resistant.

 While olive leaf has been used medicinally for centuries, research on the herb’s immune-protective effects only began in earnest in the 90s.* That’s why most studies to date have been performed in test tubes.

So it’s quite a big deal that in a double-blind, placebo-controlled human clinical study—the gold standard of scientific research—has confirmed olive leaf’s ability to enhance the immune response.*

The study that changed things

The eight-week study, which enrolled 29 healthy men, found that olive leaf extract can change the response of white blood cells called peripheral blood mononuclear cells (a class of immune cells which includes T cells, B cells, natural killer cells, and monocytes).* In the study, olive leaf “turned off” the response that causes immune havoc, while “turning on” the response that promotes immune balance.*

The researchers speculated that this could explain “the claimed health outcomes” associated with the herb. In other words, it validates why so many people support seasonal wellness by taking olive leaf extract.*

Immune support for seasonal wellness

So, if you add the exciting potential that this study suggests to what we already know about olive leaf’s natural protective antioxidants, you may just have the perfect formula for a healthy super-boost to your immune system. 

* 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. 



  1. Aziz NH, et al. Comparative antibacterial and antifungal effects of some phenolic compounds. Microbios. 1998; 93(374):43-54.
  2. Tranter HS, et al. The effect of the Olive phenolic compound, oleuropein, on the growth and enterotoxin B production by staphylococcus aureus. J Appl Bacteriol. 1993; 74(3):253-59.
  3. Boss A, et al. Human intervention study to assess the effects of supplementation with olive leaf extract on peripheral blood mononuclear cell gene expression. Int J Mol Sci. 2016 Dec 2;17(12). pii E2019.