Benefits of St Johns Wort: Boosts the Immune System & Fights Infections.St Johns Wort, contains compounds that are similar to CBD. These compounds are called N-acylethanolamines (NAEs) and interact with the enzyme which breaks down endocannabinoids in the body. Certain N-alkylamides in St Johns Wort also engage the CB2 receptor. These are cannabimimetic compounds, meaning that these compounds are like cannabinoids and engage the endocannabinoid system. St Johns Wort is often used for the common cold to boost the immune system and we now know that cannabis does the same. Boosting your immune system helps to fend off infection. St Johns Wort is also thought to reduce inflammation and act as an antioxidant. The herb may have pain-relieving effects as well.