Published on June 3, 2024 at 13:38

Written in collaboration with Clera

Cold sores

A cold sore is an infection caused by the herpes simplex virus type 1 (HSV-1), taking the form of small reddish blisters located close to the lips and mouth. Highly contagious, cold sores can be transmitted by close contact with the virus. Inconvenient and often painful, there are nevertheless solutions to relieve cold sore symptoms, such as CLERA™.

The wildfire cycle

The cold sore cycle is usually divided into 6 distinct phases.

  • Phase 1: Tingling or itching around the mouth
  • Phase 2: The formation of red vesicles
  • Phase 3: The appearance of the cold sore
  • Stage 4: Vesicles split to form red indentations (this stage is the most painful and contagious)
  • Stage 5: The lesions disappear, leaving a yellowish crust (when the yellow crust falls off, the affected area becomes sensitive)
  • Phase 6: The irritated area gradually disappears as the immune system fights the cold sore to render it inactive. 

Not touching the cold sore is important, as this simple gesture can cause scarring and delay healing. It is also recommended, as much as possible, to not come into contact with others to avoid spreading.

Risk factors

In the case of a person who has already experienced a cold sore, the virus remains dormant in the body, liable to reappear at any time. Various factors can trigger a cold sore, for example, stress, exposure to sunlight, a weak immune system, hormonal changes and so on.

Prevention at home

Certain lifestyle habits help curb the spread of cold sores.


Inadequate hydration affects the immune system, resulting in dry mouth and chapped lips, which can lead to cold sores.

On a daily basis, men need to drink around 3.7 L of water, while women need 2.7 L1. However, this may vary depending on the body and level of physical activity. Adequate hydration enables the kidneys to filter waste products and prevent fatigue, all while limiting cold sore attacks.


Diet affects lip health, the immune system, and cold sore outbreaks. Consumption of refined sugars and processed foods should be limited, even avoided. Instead, focus on green vegetables, whole grains, healthy natural ingredients and foods rich in lysine (e.g. beans, shrimp and chicken), an amino acid with antiviral properties.

Skin protection

Summer and winter alike, it's important to protect the body and face from UV rays to avoid sunburn. A moisturizing lip balm with SPF is a good idea for lip health, but the whole body should still be protected with sunscreen to preserve the immune system. Sunburn affects sleep and the skin's general health, giving the herpes virus an opportunity to activate.

CLERA treatment™

CLERA™ - Cold sore gel treatment


CLERA™ is a topical solution based on tin fluoride, applicable to the face and lips only. The product works at the level of cold sore prevention. When used at the first symptoms, it can accelerate healing in as little as two days2. However, if you've missed your chance to accelerate healing, apply CLERA™ to soothe and relieve cold sore symptoms until the blister collapses and the immune system returns the cold sore to its inactive state.

More specifically, CLERA™ can be effective for the following actions:

  • Prevention: Prevents the spread of herpes simplex virus type 1 (HSV-1), before tissue damage occurs
  • Acceleration: Heals cold sores quickly and effectively
  • Relief: Calms itching, redness and discomfort
  • Reduction: Reduces the size of cold sores and the number of repeat offences

CLERA™ is intended for adults and children aged 12 and over. 

Keep CLERA™ handy at all times to prevent cold sores!


1- The National Academies of Sciences, Engineering, and Medicine

2- William J. Embro, DDS "Treatment Of Herpes Simplex Labialis With Stannous Fluoride Gel", Journal of Cosmetic Dermatology", April, 1999. 

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