Cold sores are caused by the herpes simplex I or II virus infecting the mouth and surrounding area. After the initial infection, where a cold sore lasting maybe a week or two will emerge, the herpes virus can go dormant for an indefinite amount of time. It is only when the conditions are right for the virus to re-emerge that cold sores will start appearing again. Those conditions could emerge every week or month for one person and never again for another.
Cold sores, sometimes known as oral herpes, are not an infectious disease but a viral infection. They usually feel itchy, hot, painful, and sensitive. This is mostly the immune response, not the virus damage itself.
Most people are infected with the herpes simplex type I virus. It can spread without you even having a cold sore visible, and can infect other parts of the body, like the genitals, fingers, and eyes. Where you develop herpes is largely dependent on the herpes simplex virus type, with herpes simplex I infecting the face most of the time and sometimes the genitals, and genital sores are usually caused by the herpes simplex II virus infecting the genitals.
To understand whether CBD will be useful for treating your cold sores, it can help to understand what causes cold sores. The herpes simplex virus is a retrovirus, a particularly horrifying type of virus. It literally hijacks the cell to produce copies of itself, causing the cell to digest itself and die. The first step in this infection is when the virus attaches to a receptor on the outside of the cell it wants to infect. It then injects the code needed to make the virus enter the cell’s interior, where the machinery of the infected cell picks it up, converts it into DNA and inserts it into the DNA of the cell itself.
The cell then thinks that the viral DNA is its own, so it makes copies when the conditions are right. On the outside of the viral DNA there are little epigenetic switches, which tell the DNA copying proteins when to make copies. When a cell is experiencing stress, or is receiving signals from other cells that it needs to protect itself, or a number of other undiscovered triggers, it starts to make transcribe the viral DNA into viruses. Eventually, there are so many viruses that the cell dies, bursting open and spreading the viruses far and wide.
Before this happens, the virus is invisible to the immune system because the cell looks perfectly healthy. The immune system is surprised to find a huge number of viruses and takes a while to catch up. Very soon, however, the infected area is flooded with immune cells trying to mop up the viruses before they can spread. Blood flow increases to the affected area, healing factors and nutrients are concentrated to help healing. This is called an inflammatory response.
After a few days or weeks the cold sore heals. However, if even one virus has infected a single cell, it is lying dormant and undetectable, impossible for the immune system to detect. When the conditions are right, the whole process begins again. This is why cold sores are temporary, but you will likely have them for the rest of your life.
Spreading Herpes Simplex Virus
People with weakened immune systems are particularly vulnerable to infections like herpes, so preventing its spread is important. Herpes can be contagious even if the infected person does not have any cold sores or lesions on their body. This is one of the reasons for so many people being infected. Without displaying the signs and symptoms, it is so much easier to spread the virus.
If you have a herpes sore on your body, which look like little fluid filled blisters that eventually form a scabby crust, make sure you wash your hands thoroughly with soap after touching it. Picking or itching at a cold sore can make it spread to other parts of the body, so it is worth avoiding touching it. Do not share your towel, lip balm, or underwear with anyone if you are at any point in the cold sore cycle. Try avoid skin contact. Person to person close contact is the most common method of infection, so take reasonable precautions if you are suffering from cold sores.
To be clear: a canker sore is not a cold sore, they are caused by different things. You can learn more about canker sores here.
Treating Cold Sores
Now you know what causes cold sores, you can understand why some drugs work against them. Drugs like acyclovir (Zovirax), famciclovir (Famvir) and valacyclovir (Valtrex) act as antiviral medicines, preventing the virus from being produced in the infected cell. These are effective and powerful drugs can (rarely) have some severe side effects that can be worse than the herpes infection itself. Many people use home remedies instead, like tea tree oil.
CBD for Cold Sores
CBD, or Cannabidiol, is a chemical derived from the cannabis plant. It has a wide range of effects on the endocannabinoid system. This system consists of receptors on neurons that extend from the brain to the skin. The reason why it is believed that CBD could be beneficial in treating cold sores is that it is a powerful anti-inflammatory.
When the body is infected with herpes and the viruses decide that they are going to start replicating and killing cells, the body produces an immune response to deal with it (see above). Using an anti-inflammatory like CBD can help to reduce this response and make the symptoms like itching, pain, swelling and heat much less severe.
The unintended side effect of this reduction in inflammation is that the cold sore virus finds it easier to reproduce and spread, meaning the immune system can take a while longer to contain the cold sore outbreak. There have been more tests with THC, a close relative of CBD, for herpes, and they appear to be quite successful in reducing the symptoms of cold sores. Only time will tell.
Preventing Cold Sores with CBD
At present there is no real evidence that CBD can prevent cold sores from occurring. The useful properties of CBD reduces the symptoms, but don’t impact on what causes cold sores in the first place, as far as we know. Antiviral medications are sometimes successful in reducing the frequency of cold sore outbreaks, but because CBD is not a proven antiviral medication, it is very unlikely this effect can be obtained from its use.
The scientific literature on CBD is sadly limited. Its haphazard legal status across the United States makes it very difficult to study. The trials that have been performed are generally small scale, many without proper double-blind controls, and of limited use. It is therefore advised that anyone considering using CBD as a treatment for their cold sores, or any other condition, proceed with caution before using CBD. Talk to your doctor, they will help you get the best results.