Cold sore: Is castor oil effective against the proliferation of the herpes virus?

Cold sores are a recurring skin condition caused by the herpes simplex virus 1, or HSV-1. This virus remains in the body after an initial infection, which often occurs during childhood. Highly contagious, this virus is transmitted through direct contact. Cold sores typically appear on the edge of a lip and take the form of a cluster of blisters filled with pus. These quickly become opaque before bursting. In addition to blisters, herpes can sometimes cause fever and feelings of fatigue. Generally, a cold sore will heal spontaneously after 10 to 15 days and does not leave a scar.

To promote healing, it is advised not to touch the cold sore. If you happen to do so, immediately wash your hands and avoid touching your eyes, to prevent a case of keratitis.

Highly praised for its numerous benefits for the skin, castor oil is sometimes considered a natural solution for cold sores. However, to date, its potential effects on herpes have not been the subject of any study. Furthermore, although it has antibacterial properties, there is no evidence to support its antiviral effectiveness. Therefore, it is currently impossible to assert that castor oil can act on the herpes virus.

We can only hypothesise that castor oil might potentially alleviate the itching and tingling that sometimes accompany cold sores. Indeed, this vegetable oil is known for its soothing properties, which come from its richness in fatty acids. These could indeed inhibit the synthesis of certain pro-inflammatory cytokines, such as TNF-α and interleukins 1β and 6 (IL-1β and IL-6). Moreover, studies suggest that castor oil could inhibit phospholipase A2enzymes, some of which release arachidonic acid. However, the metabolism of the latter by a cyclooxygenase or a lipoxygenase leads to the formation of inflammation mediators such as prostaglandins and leukotrienes.

Apart from this potential soothing action, the castor oil does not seem to be able to act against cold sores nor accelerate their disappearance.

How do we treat a cold sore?

In the event of cold sores, doctors and pharmacists typically recommend oral or topical treatments containing aciclovir, a commonly used antiviral to reduce the intensity of herpes outbreaks. However, it should be noted that this type of treatment does not reduce the frequency of outbreaks: it can merely reduce the duration of contagion and alleviate the current outbreak.