Cold sores / Fever blisters - Treatments and cures.
This page discusses non-prescription products for cold sores (categories list), like those you'll find on the shelves of your neighborhood store.
(For information about other treatment approaches, use the Home-remedy or Prescription links above.)
How do OTC treatments work?
Non-prescription (over-the-counter) cold sore/fever blister products typically provide their treatment benefit via one of the following modes of action.
- They help to create an optimal healing environment, so the sore heals as quickly and as uneventfully as possible.
- They provide palliative treatment, meaning they help to relive the pain, itching, and burning associated with cold sores.
- They create an inhibitory effect on the herpes virus that, in turn, helps to stunt cold sore formation.
Some products take a broad-based approach.
In some instances, a cure's formulation maybe focused on just one of the above treatment approaches. More often than not, however, you'll find that a manufacturer has designed an all-encompassing proprietary formulation (containing a number of different compounds) in an attempt to increase their product's overall effectiveness.
Over-the-counter cold sore treatments, medications, products.
- Herpes virus inhibitors. - Docosanol (Abreva ®)
- Traditional / proprietary OTC products that contain the compounds:
- Numbing agents / Anesthetics.
- Antibacterial products.
- Scab moisturizers.
- Sun screens.
» Herpes virus inhibitors - Docosanol (Abreva ®).
How does it work?
This compound has been shown to have an inhibitory effect on herpes virus replication (presumably by way of inhibiting the fusion between the host cell membrane and the virus envelope).
The clinical significance of this is that, when it's applied to the area where a fever blister is starting to form, it helps to stifle the sore's development (the lesion is less severe, has fewer symptoms, a shorter duration).
As a side note, one key to the effectiveness of treatment with docosanol is that it must be applied at the very earliest signs of cold sore formation. Late initiation of treatment provides much less, if any, benefit in regards to reducing healing time.
How do you use Abreva ®?
Abreva ® is a white cream that dries clear. It has no smell. It comes packaged in either a tube or "pump." Both types of packaging contain the exact same form of the product.
Treatment should be initiated at the very earliest sign of cold sore formation (the "tingle" stage). (It's ok to go ahead and apply the cream before any visual sign of fever blister development is visually apparent.)
Apply the cream on and around that region of your face or lip where you feel your cold sore forming. (This product is for external use only.) The cream can be spread with your finger or an applicator (like a Q-tip). Wash your hands afterward so you don't spread the herpes virus to others, or even other parts of your own body.
The cream should be applied repeatedly (every 3 to 4 hours) throughout the waking hours of your day (5 times daily is recommended). Treatment may be continued for up to 10 days, or until your cold sore's scab has fallen off, whichever is earliest.
FDA approval. / Over-the-counter availability.
Abreva ® is the only over-the-counter (non-prescription) medication that has been approved by the FDA "to shorten both healing time and the duration of symptoms" of cold sores. It received this approval in July 2000. (FDA approval is only given after a manufacturer has submitted research findings that show evidence that their product is safe and effective for its intended use.)
What's different about Abreva ® compared to other OTC products?
There are many OTC fever blister medications that include FDA-approved compounds in their formulations. However, the difference between Abreva ® and these products is that the FDA-approved status of their ingredients is one of providing palliative treatment (relieving symptoms such as pain, itching and burning) and not, as is the case with docosanol, having an affect on the time it takes for cold sores to heal.
Keep in mind, however, that FDA approval does not necessarily equate with the term "guaranteed cure." Approval status does mean that a manufacturer has provided research evidence to the FDA that suggests that their product is safe and effective in regards to its claims and therefore is an appropriate treatment approach for a certain type of condition. But it does not mean that the product will unequivocally be the right cure for you.
How effective is docosanol?
There are two published research papers that are typically cited when discussing the demonstrated effectiveness of docosanol in treating fever blisters.
Habbema (1996) reported that application of 10% docosanol cream (initiated at the very earliest signs of cold sore formation) shorted healing time in test subjects, on average, by approximately 3 days (as compared with placebo treatment or late treatment with docosanol cream).
Sacks (2001) reported a more modest treatment benefit. Test subjects initiating early application of 10% docosanol cream only experienced, on average, an 18 hour reduction in healing time for their cold sores.
As suggested by both of these studies, the effectiveness of docosanol treatment is significantly improved when application of the cream is initiated at the very earliest signs of fever blister development (i.e. the tingle stage). Late application may have little to no benefit.
» Numbing agents. / Anesthetics.
Topical anesthetics (tetracaine, benzocaine or lidocaine) and other numbing agents (benzyl alcohol, camphor or phenol) are frequently included in the ingredient list of non-prescription fever blister products. The most obvious treatment goal of this approach is one of helping to attenuate cold sore symptoms (burning, itching and pain), however, there may be other benefits too.
Cassuto (1989) found that herpes sufferers experienced symptoms over a fewer number of days (2.1 vs. 5.1 days) when an anesthetic cream (lidocaine and prilocaine) was applied. Kaminester (1999) found that the application of an anesthetic (tetracaine) was especially beneficial for reducing itching symptoms. There may be some evidence (Kaminester 1999) that the use of an anesthetic can help to reduce fever blister healing times (5.1 vs. 7.2 days).
» Traditional / proprietary OTC treatments.
A number of OTC products contain compounds (such as zinc, lysine, benzylkonium chloride and tannic acid) that, while not tested and proven so extensively in scientific studies, have some evidence and a history that suggests that they are useful in managing cold sores.
Presumably these products work by way of having an inhibitory effect on the herpes virus, which in turn, helps to limit sore formation. However, for some of these treatment approaches their precise mechanism is still up to debate. In some cases, the concept for the product seems to be derived from known home remedy cures.
» Topical zinc compounds.
Research suggests that topical medications (ointments, creams) that contain zinc compounds (zinc oxide, zinc sulfate) may help to speed up the time it takes for cold sores to heal. Especially in those cases where the treatment was begun promptly upon the first signs of a developing outbreak.
A zinc oxide / glycine cream was found to shorted the average healing time from 6.5 to 5.0 days. 50% of a treatment group applying 1% zinc sulfate gel to their sores were symptom free at 5 days, as compared to 35% of the placebo group were. (cited from Opstelten 2008)
» Products that contain benzylkonium chloride.
Research suggests that the compound benzylkonium chloride (a disinfectant and antiseptic) is effective in inactivating the herpes virus (presumably by way of disrupting the virus's envelope). Some cold sore medications include this compound as their primary active ingredient.
» Topical products that contain lysine.
Research has suggested that taking lysine as an oral supplement can be effecting in helping to prevent fever blister outbreaks. In a similar vein, research may suggest that lysine incorporated in the formulation of topical creams may have some benefit too.
» Antibacterial medications.
The herpes virus is just that, a virus, not a bacterium. This means that those compounds that kill bacteria (antibacterial agents) won't have the same killing effect on virus particles. (Because they're different types of 'life' forms.) However, antibacterial products can be useful fever blister treatments, once they have formed.
They do this by way of helping to prevent a secondary bacterial infection in the sore. As a result, it is more likely to heal promptly and uneventfully.
» Medications that moisturize fever blister scabs.
Moisturizers, protectants and lip balms can be useful in treating cold sore lesions once they have scabbed over. These products help to the soften scabs so they are less likely to crack and bleed. Look for ingredients such as: allantoin, calamine, cocoa butter, and petrolatum (petroleum jelly).
» Medications that provide sun screen protection.
Exposure to the ultraviolet light (a component of daylight and the lighting used in tanning beds) is known to trigger cold sore outbreaks.
For this reason, you'll find that many lip balm medications contain zinc oxide (or other blocking agents) that can provide sun-screen protection. In general, it's best to choose a product that has a SPF value of 15 or greater. (Rooney 1991)
Some brand names associated with products that provide lip sun-screen protection are: Ambesol®, Blistex®, ChapStick®, Herpecin-L®, Neosporin®.
! Use precaution when applying anything to a cold sore, the herpes virus is contagious.
It's important to keep in mind that all stages of cold sore formation should be considered to be contagious. To help from spreading the herpes virus to others, or even other parts of your own body, after applying any medication or treatment you should always wash your hands.