Cold sores go through five distinct stages in their relatively short lifespan. But, during that time, they can be painful and unsightly.

Whether you choose to treat a cold sore or not act is a matter of personal preference, but early treatment with the Virulite Electronic Device during the prodromal/tingling stage is highly recommended. It can substantially reduce the healing time and prevent the oozing if you take action when you first experience the tingle.[1]

Cold sores will eventually go away on their own. But for most people, the worst thing about a cold sore is the oozing of a clear liquid from an open blister during stage 3. So, knowing how to stop a cold sore from weeping can be a valuable lesson to learn.

The initial symptom of a fever blisters is a tingling sensation on the lip line. Then, a blister will form. A few days later, that blister may start oozing liquid. Then, that blister will crust or scab over, and then start to heal.

Why Do Cold Sores Ooze Yellow Fluid?

As a fever blister develops, it fills with clear liquid. This fluid forms as your immune system’s response to the herpes virus. As the blister stage of the cold sore lifecycle transitions into the ulcer stage, the blisters burst. Once it bursts, the result is an open sore and drainage of fluid. This can be minimal or quite excessive depending on the size of the blisters.

The drainage of clear fluid is normal and healthy. Although the visual can leave something to be desired, the oozing is natural. Fluid drainage is a sign of healing. This means that your blisters have popped (presumably naturally) and you are one step closer to the end of the lifecycle.

To summarize:

  • Cold sore blisters are packed with fluid. This is one of the reasons why they are so large and ugly. When your sores naturally pop, the liquid inside begins to drain instantly. Clear fluid oozing is natural and not a reason for concern.
  • The color of your blister fluid holds little significance. While most fluid is clear, some pus can occur if the cold sore is infected with bacteria.

How Long Do Cold Sores Ooze?

Cold sore liquid oozing will last until the last bit of fluid has been released. Many times, the duration of drainage is determined by the size of the sores. This varies from person-to-person and will also vary within your own blisters. Some will drain faster than others.

As long as your blister drainage is contained in a sanitary way, you should be fine. Cold sore bursting (and oozing) is the hallmark of the ulcer stage. You can take heart in knowing that no stage lasts more than 48-72 hours. Your cold sore will be replaced by a scab very soon.

To recap:

  • Fever blisters drain (ooze) until all of the liquid that was housed inside of the blister is released. While this process does not take place instantly, it should not last for too long.
  • Once a blisters bursts, it becomes susceptible to the open air. This is good as it relates to drainage. Somewhat of a natural drying out process naturally begins that will result in moisture being removed from the skin lesion.
  • Once all of the fluid has been drained from your sore, the newly developed ulcer will soon be covered by a scab.

What Are the Five Stages of a Cold Sore?

Listed below is an overview of the cold sore lifecycle and what you can expect.[2]

  1. Prodromal Stage: The initial stage is the tingle or prodromal stage. This stage is hallmarked by a tingling or burning sensation where HSV-1 transmission has taken place. This location is typically a centralized area of the lip or mouth. Itchiness, redness, and minor swelling are also common symptoms. Of valuable importance, the tingle stage is the best time to treat a developing cold sore with the Virulite Electronic Device.
  2. Blister Stage: Roughly 48 hours after the tingle stage has ended, a cluster of fluid-filled sores will form. This portion of the cycle is where cold sores are born. Typically small and in clusters, the blister stage can be quite painful. The symptoms may occur not only on the primary area of concern but also on surrounding skin. Redness and swelling of surrounding skin are common.
  3. Ulcer Stage: Regarded as the most painful stage, the ulceration stage involves the natural bursting of blisters. The result of this process is an open and painful sore that produces fluid drainage. The appearance of a red circle around the newly formed ulcers is common. The ulcer stage typically begins four days after the prodromal stage.
  4. Scab Stage: Once your blisters have drained and dried out the open sores will be covered by scabs. While this stage can be quite painful as your scabs begin to crack (and potentially bleed), this portion of the lifecycle marks a turning point as a sign that your outbreak is coming to an end. The scab stage usually takes place 5-8 days after the prodromal stage began.
  5. Healing Stage: The final stage is marked by the natural flaking away of your scabs and new skin. While some minor swelling may occur, the healing stage is the official end of the lifecycle. The healing stage occurs 8-10 days after your initial symptoms began.

While the average cold sore lifecycle can roughly last ten or more days via natural means, you can reduce this time. You can potentially cut your outbreak from 10 days down to as little as 72-96 hours with the Virulite Electronic Device. It’s an FDA-approved treatment that works.

Can the Weeping Stage Be Skipped?

If your cold sores can be dried out during the blister stage, it is possible to bypass the weeping stage to some degree. Because weeping primarily depends on the size of your blisters, drying out each sore will diminish the fluid inside. The more each sore dries, the less liquid it will contain.

Bypassing the weeping stage does not mean avoiding the ulcer stage. What is left of your blisters (even after being dried out) will still burst. The only question is how much of the fluid has remained inside.

To summarize:

  • You can skip the weeping stage by drying out your active blisters. Once moisture is taken away from a sore, it will naturally begin to shrink. As it dries up, the fluid will also start to dry.
  • Although the ulcer stage will transpire after your blisters burst, the amount of fluid remaining could be quite low. Depending on the size of your sores, it is possible to have no weeping during the ulcer stage.

How long will my cold sore ooze a clear fluid?

What to Do if Your Cold Sore Keeps Oozing

If you are having trouble getting sore oozing and weeping under control, there are techniques that you can use. These include drying measures and protective sealing methods.

Noted below are a few techniques and products that can keep blister oozing under control:

  • The first measure is a drying method. By applying small amounts of tea tree oil to your sores, you can dry up any remaining fluid. Although applying an essential oil to an ulcer could be painful, the oil will aid in the drying process. Because some blisters fail to burst, fluid is often caught inside, and drainage can be a slow process.
  • The application of petroleum jelly will add a moisturized seal to your ulcers.[3] While this will not dry out your sores, the jelly will seal off any weeping concerns. This can be a technique to use until the ulcer stage has passed and scabbing commences.
  • The use of HERP-B-GONE cream can prevent your blisters from oozing. Complete with a host of natural oils, it is fast-acting and fast-healing. It has quickly became one of the most popular treatments on the cold sore market.
  • Another way to prevent oozing during the ulcer stage is to cover it with a Compeed medicated cold sore patch.[4] It’s an excellent option if you’re feeling self-conscious.

What if My Cold Sore Popped on its Own?

If your cold sore has popped on its own, you have nothing to worry about. This is the blister stage transitioning to the ulcer stage. This is a normal and healthy process.

The only time you should be concerned is if your blister has popped accidentally. You must clean the area and monitor any unusual changes. Sores that pop through unnatural means can prompt viral spreading and infection. Not to mention bacterial superinfection, delayed healing and potential scarring.

To recap:

  • If your blister has popped on its own, then you have nothing to worry about.
  • If your sore has been popped accidentally, you should monitor the area for any changes. While pain is to be expected, changes such as extreme swelling and discoloration could be a sign of bacterial infection.
  • If the newly formed ulcer begins to develop a scab, then the natural healing process is still on course.

Can an Oozing Cold Sore Spread the Virus?

Oozing and weeping can spread the virus to other areas of your lip and mouth. Even your cheeks and fingers can become infected if drainage of the cold sore is not minimalized.

Being proactive during liquid drainage is essential. Through the use of gauze and cotton balls, you can better contain any oozing. Limiting where the liquid goes after escaping the blister is important.

To summarize:

  • HSV-1 can be spread to other areas of your body during the ulcer (oozing) stage. Contaminated fluid can impact areas of the lips, mouth, cheeks, and even fingers. Soaking up any drainage is vital. The use of gauze and cotton balls can be beneficial.

Is Cold Sore Pus a Sign of Infection?

The drainage of pus is a sign of bacterial infection but rather a natural part of the healing cycle.

Although pus draining from a blister is not pleasant, a bursting blister means you are one step closer to the scab stage and complete healing. It is important to treat the infection properly and avoid further complications.

Prolonged blisters that do not pop could be a sign of infection. That would directly imply that something is wrong. Infection could be to blame for a blister that refuses to burst.

To recap:

  • Pus is a sign of bacterial infection. For a cold sore to properly heal, it must burst. If the bursting of a fever blister results in pus drainage, it is important to avoid further complications by treating the infection in a proper manner.

Why is There Blood in the Clear Liquid?

While some blood loss can occur during the scab stage, bleeding can also take place during the ulcer stage. Blood that appears in fluid drainage is not entirely uncommon.

Blood that forms within liquid is often a sign of skin damage that has taken place to the blister itself. Because cold sores invade the healthy skin, that area becomes victimized by the blister cluster. Blood found in fluid drainage is likely due to skin becoming cracked during the blister stage.

The appearance of blood is usually nothing to worry about. It is important to remember that a cold sore is a flesh wound. The area where the sore resides has harmed existing flesh.

Once the ulcer stage develops, that portion of the skin has become somewhat of a crater. It has been torn away from the inside out. This form of damage can result in bleeding. This is similar to that of most any other type of abrasion or deep cut on the body.

To summarize:

  • Blood found in fluid drainage is the result of skin damage caused by the formation of the sore itself. While bleeding is primarily found during the scab stage, it can also occur during the ulcer stage.
  • Cold sores, while born from a virus, are flesh wounds. Any area of fresh and healthy skin that has been overtaken by a blister-promoting virus will result in damaged skin that can bleed.

Why do cold sores weep?

How to Stop a Cold Sore before a Blister Forms

The ideal time to stop a blister before it forms is during the prodromal/tingle stage. If you can identify the symptoms (tingling, burning, itching, etc.), you can be proactive and begin to apply treatment. Selections such as HERP-B-GONE can do a world of good.

While there are no guarantees of stopping a blister, the sooner you act, the sooner the outbreak will be gone. Acting fast can speed up the lifecycle of a cold sore thus relegating the entire outbreak to only 72 hours or so. This is a far cry from the 10-14 day duration that untreated outbreaks require.

To recap:

  • The best time to treat a fever blister outbreak is during the prodromal/tingle stage. If you wait any longer, the blister clusters will have already formed. This makes fast healing a little more difficult as the viral outbreak has already taken hold.

What’s the Best Cold Sore Weeping Stage Treatment?

The best treatment during the cold sore weeping stage is a drying agent. Essential oils can dry out cold sores during the ulcer stage and reduce fluid drainage.

Concealing your sore with a moisture barrier is also wise. There are several ways to lock in moisture while eliminating unpleasant drainage.[5] The goal is to keep the ulcer quarantined until scabbing takes hold. This is a wise choice if viral spreading is one of your primary concerns.

To summarize:

  • Weeping takes place during the ulcer stage. The best way to stop unwanted and messy oozing is to dry up the area. This can be achieved by applying tea tree oil to the ulcers. Once the area is no longer moist, any undrained fluid will begin to dry.
  • Another way to stop weeping is to keep the fluid locked in and blister moisturized. Petroleum jelly and medicated patches can all do the trick. This is an excellent action to take if you are seeking to eliminate the possibility of viral spreading.

When Are Cold Sores Not Contagious Anymore?

Fever blisters are contagious from the start of the prodromal stage until the scab has fallen off.

Contrary to popular belief, the scab stage is still a contagious stage. Just because the ulcer has been crusted over does not mean the virus has returned to a dormant state. It is merely shielded. Only one accidental or deliberate tear of your scab can result in potential viral spreading.

The question of fever blisters being contagious is often asked by those who are in a relationship. For that reason, we advise you to avoid kissing and any oral sexual activity until new skin has replaced your scab. The best solution is to wait until your lip has completely healed.


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  2. Everett R.D. (2014) HSV-1 Biology and Life Cycle. In: Diefenbach R., Fraefel C. (eds) Herpes Simplex Virus. Methods in Molecular Biology (Methods and Protocols), vol 1144. Humana Press, New York, NY
  3. Czarnowicki T, Malajian D, Khattri S, Correa da Rosa J, Dutt R, Finney R, et al. Petrolatum: barrier repair and antimicrobial responses underlying this “inert” moisturizer. J Allergy Clin Immunol. 2016;137:1091–1102.e7.
  4. Karlsmark, T. , Goodman, J. , Drouault, Y. , Lufrano, L. , Pledger, G. Randomized clinical study comparing Compeed® cold sore patch to acyclovir cream 5% in the treatment of herpes simplex labialis. Journal of the European Academy of Dermatology and Venereology. 2018; 22: 1184-1192. doi:10.1111/j.1468-3083.2008.02761.x
  5. Sheikh S, Gupta D, Pallagatti S, Singla I, Gupta R, Goel V. 2013. Role of topical drugs in treatment of oral mucosal diseases: a literature review. N Y State Dent J. 79(6):58–64.