Over-the-counter treatments & medications for cold sores (fever blisters). -

Treatment methods. Compounds used. How they work. | Abreva® (docosanol) - How effective is it? | Other OTC products (brands, active ingredients).

OTC cold sore products.

This page discusses non-prescription treatments and medications for cold sores (fever blisters), like those you'll find on the shelves of your neighborhood store.

OTC product categories:

(Use the buttons to the right for information about prescription or home-remedy treatment approaches.)

Ways OTC products work.

Non-prescription (over-the-counter) cold sore (fever blister) products typically provide their treatment benefit via one of the following modes of action.

  1. They help to create an optimal healing environment, so the sore heals as quickly and as uneventfully as possible.
  2. They provide palliative treatment, meaning they help to relieve the pain, itching, and burning associated with cold sores.
  3. They create an inhibitory effect on the herpes virus that in turn helps to stunt the extent of lesion formation.
Figuring out how a product works.

Rather than just providing one aspect of cold sore management, some OTC products combine multiple compounds so they can be useful in managing cold sores on multiple fronts.

To help you better understand how the product you're considering actually works, instead of just listing brand names we've also listed the actual compounds typically used to provide different cold sore treatment benefits. Simply compare your product's ingredient list to the compounds mentioned on this page.

» Herpesvirus inhibitors - Docosanol (Abreva ®).

Docosanol is an antiviral compound that has been shown to be effective in shortening both the healing time and duration of symptoms of cold sores.

a) How does it work?

Docosanol has an inhibitory effect on herpesvirus replication (reproduction) by way of inhibiting the fusion between the host cell membrane and the virus envelope. (It makes it difficult for the virus to enter into cells where it can replicate.)

Pictures of herpes simplex virions.

Herpesvirus particles (virions).

Because fewer virus particles (virions) are formed, the cold sore's formation is stunted (it's less severe, has fewer symptoms and shorter duration).
Early treatment is key.

Just like with any other type of antiviral medication, the key to effectiveness with docosanol is that it must be applied at the very earliest signs of cold sore formation (a time period when virus replication is still active and can be affected). Late initiation of treatment provides much less benefit.

b) How effective is docosanol (Abreva®)?

There are two studies that have historically been cited when discussing the effectiveness of docosanol in treating cold sores/fever blisters.

  • Habbema (1996) reported that the application of 10% docosanol cream (initiated at the very earliest signs of cold sore formation) shorten 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 the early application of 10% docosanol cream only experienced, on average, an 18-hour reduction in healing time for their cold sores.

Section references - Habbema, Sacks

c) How is Abreva® used?

Product details -

Abreva® is a white cream that dries clear. It has no smell. It can be purchased as a cream in a tube, in a "pump" dispenser or as a patch.

How the cream is used.
  • Treatment should be started once the very earliest sign of cold sore formation is felt (the "tingle" stage).
  • Apply the cream on and around that region of your face or lip where you feel the cold sore forming. (Abreva® is for external use only.)
  • The cream can be spread with your finger or an applicator like a Q-tip. (Wash your hands after application 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 is continued until your cold sore's last scab has fallen off, or else for up to 10 days (whichever is earliest).


d) Abreva® has FDA approval.

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® and its FDA approval vs. other OTC products?

Many OTC fever blister medications contain FDA-approved compounds in their formulation. But these compounds are only recognized as agents for relieving symptoms, such as itching and burning.

In comparison, Abreva® (docosanol) has FDA recognition that it helps to relieve symptoms and reduce the time needed for cold sore healing.

» 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 associated with the use of these compounds is reducing cold sore symptoms (burning, itching and pain), however, there may be other benefits too.

Research studies.
  • Cassuto (1989) found that symptoms were experienced over a fewer number of days (2.1 vs. 5.1 days) when an anesthetic cream (lidocaine and prilocaine) was applied to cold sores.
  • Kaminester (1999) determined that the application of anesthetic helped to reduce fever blister healing times (5.1 vs. 7.2 days).


However, Worrall's (2009) review of published literature concluded that the evidence supporting the curative effects of anesthetics was inconclusive.

Section references - Cassuto, Kaminester, Worrall

Products to look for.

Some brand names of cold sore products that contain numbing agents are: Anbesol®, Blistex®, Campho-phenique®, Carmex®, Orabase®, Orajel®, Tanac®, Viractin®, Zilactin®.

Proprietary OTC treatments.

A number of OTC products contain the compounds zinc, lysine, benzylkonium chloride and tannic acid.

And while these compounds haven't been as extensively studied as others, there is some evidence and history that suggests that they are useful in cold sore management.

How do they work?

Presumably, these compounds work by way of having an inhibitory effect on the herpes virus, which in turn, helps to limit the extent of lesion formation (smaller lesions generally correlate with quicker healing). However for some of them, their precise mechanism is still up to debate.

The concept for the use of some of these items seems to be derived from known home remedy cures.

» Topical zinc compounds.

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 their application is begun promptly upon the first sign of lesion formation.

  • 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.

(Opstelten 2008)

However, Worrall (2009), after performing a review of published literature, felt that the evidence for the use of zinc compounds was inconclusive.

Section references - Opstelten, Worrall

» 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.

Products to look for.

Some brand names associated with these types of products are: Viroxyn®, Releev®.

» Topical products that contain lysine.

Some research suggests that taking lysine as an oral supplement may be effective in helping to prevent fever blister outbreaks (more details). In a similar vein, lysine formulations used as a topical cream may have some benefit too.

Products to look for.

Some brand names associated with these types of products are: SuperLysine®, Herpecin-L®.

» Antibacterial medications.

The herpes virus is just that, a virus, not a type of bacteria. And for that reason, antibacterial compounds won't be effective against it. However, they can be helpful in managing fever blisters once they have formed.

They do this by way of helping to prevent secondary bacterial infection in the sore. As a result, it is more likely to heal promptly and uneventfully.

Products to look for.

Some brand names associated with these types of products are: Neosporin®, Polysporin®.

» Medications that moisturize fever blister scabs.

Emollients, moisturizers, protectants and lip balms can be useful in treating cold sore lesions once they have scabbed over. They help to soften the scabs so they are less likely to crack and bleed. Look for ingredients such as: allantoin, calamine, cocoa butter, and petrolatum (petroleum jelly).

Products to look for.

Some brand names associated with these types of compounds are: Ambesol®, Blistex®, ChapStick®, Herpecin-L®, Neosporin®.

» Medications that provide sunscreen protection.

Exposure to the ultraviolet light (a component of daylight and the lighting used in tanning beds) is generally considered to be a trigger for cold sore outbreaks.

The formulation of many cold sore products includes zinc oxide, or other blocking agents, that provide sun-screen protection. It's best to choose a product that has an SPF value of 15 or greater. (Rooney 1991)

Research studies.

As much sense as using sunscreen would seem to make, not all studies have necessarily confirmed that using one is beneficial.

  • Rooney (1991) exposed test subjects to ultraviolet light. None of the participants using a sunscreen developed cold sores whereas 71% of those given the placebo did.
  • But a study (Mills 1997) evaluating skiers in natural outdoor conditions found no benefit to using sunscreen lotion.

Section references - Rooney, Mills

Products to look for.

Some brand names associated with products that provide lip sun-screen protection are: Ambesol®, Blistex®, ChapStick®, Herpecin-L®, Neosporin®.

Hand washing graphic.

Always wash your hands after treating a cold sore.

! Use precaution. 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.
So 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.

Additionally, you shouldn't share topical cold sore medications (creams, ointments, balms, etc...) with others.


 Page references sources: 

Cassuto J. Topical local anaesthetics and herpes simplex.

Habbema L, et al. n-Docosanol 10% cream in the treatment of recurrent herpes labialis: a randomised, double-blind, placebo-controlled study.

Kaminester LH, et al. A double-blind, placebo-controlled study of topical tetracaine in the treatment of herpes labialis.

Mills J, et al. Recurrent herpes labialis in skiers. Clinical observations and effect of sunscreen.

Opstelten W, et al. Treatment and prevention of herpes labialis.

Rooney JF, et al. Prevention of ultraviolet-light-induced herpes labialis by sunscreen.

Sacks SL, et al. Clinical efficacy of topical docosanol 10% cream for herpes simplex labialis: A multicenter, randomized, placebo-controlled trial.

Worrall G. Herpes Labialis.

All reference sources for topic Cold Sores.