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Cold Sores

Cold Sore Introduction

Cold Sores are the result of infection with Type-1 Herpes simplex virus, although the Type-2 herpes virus can also cause cold sores. The primary means of transmission for the herpes simplex virus is via skin to skin contact with an individual who is shedding the virus. It is possible to transmit herpes simplex even though there are no visible lesions present.

Once an infection of the Herpes virus occurs, the virus is present for the lifetime of the host. Factors such as stress, immune changes, and UV exposure can trigger reactivation of the virus at various times and may result in cold sore outbreaks. The initial incubation period for herpes simplex is 2-20 days (primary infection), with most subsequent outbreaks lasting 7-14 days. It is also known that hormonal fluctuations, like those of menstruation and pregnancy, can also stimulate cold sore outbreaks. [1]

Cold Sore Signs and Symptoms

Herpes labialis (Cold Sores) outbreaks often have a “prodromal” phase which occurs before the actual sore develops. This prodrome takes the form of a tingling or itching sensation at the sight of the future lesion. Cold sores appear as red spots on the skin that soon give rise to clear blisters (vesicles) that are most commonly grouped together and can be quite painful. As the cold sore progresses, the blisters may become filled with pus and later the overlying skin will slough off and leave behind an ulceration in the skin. This ulceration later becomes crusted over and is prone to secondary infection. [2] It is common for general symptoms such as fever, headache, and swollen lymph nodes to be present. Caution: any cold sores that occur on the upper part of the face or near the eyes must immediately be referred to a qualified health practitioner as this can lead to serious complications.

Conventional Cold Sore Treatment

Conventional treatment for cold sores generally consists of a watch and wait strategy. The herpes virus usually lies dormant in the nerve that supplies the eye and skin until its reactivation. In serious cases of Herpes simplex infection, pharmaceutical agents such as acyclovir, Valacyclovir, and famciclovir may be used to prevent outbreaks. Herpes simplex keratitis, is the inflammation of the cornea caused directly by the infection. When the eye is involved, herpes simplex typically affects the cornea, conjunctiva, or eyelids. Ophthalmologic infections fall under the category of secondary infection, and are common in persons suffering from herpes simplex outbreaks. These particular infections are usually treated with trifluridine eye drops or by the application of topical antimicrobials, such as neomycin-bacitracin ointment.[3]

Supplements helpful for Cold Sore Treatment

L-Lysine Lysine is an essential amino acid that cannot be manufactured in the human body. It is thought that Lysine competes with Arginine, another amino acid , which is necessary for the replication of the herpes simplex virus. Similarly, large quantities of Arginine can stimulate herpes simplex outbreaks. The interaction of Lysine and Arginine, and their associated roles in the herpes infection, is a reason that a modification of the diet must take place in persons wanting to prevent and treat a Herpes/Cold Sore outbreak. Foods to be avoided are those with a high level of Arginine, and include; chocolate, nuts, and gelatin. Lysine rich foods should, however, be included. Lysine-rich dietary sources include; dairy, fish, chicken, eggs, mung bean sprouts, and seafoods. [4, 5, 6, 7]

Monolaurin Monolaurin is a compound that is derived from Lauric acid (a product of coconut oil) and glycerine. Monolaurin has been traditionally used in food and cosmetic production for its anti-fungal and anti-microbial properties. Monolaurin posseses certain anti-viral activity and is particularly effective against lipid bound virus types, like herpes. It seems that monolaurin inhibits the release of the viral particles from the infected host cell, which can stem the spread of an infection and breakout of both herpes and cold sores. [8]

Vitamin C (topical and internal) Vitamin C is an important antioxidant nutrient that is essential to human health. In addition to Vitamin C’s well known positive effects on health when it is taken internally, there seem to be additional benefits when it is applied as a topical agent in treatments of herpes outbreaks. The topical use of Vitamin C has shown to be effective in reducing the duration of outbreak with scabbing, as well as the number of days with worsening symptoms. [9] Internally, Vitamin C remains an appropriate supplement to use in most any illness, as it helps white blood cells function.

Zinc (Topical) Zinc has shown great promise as a preventative supplement and topical treatment for cold sores. Symptoms such as pain, burning, and tingling have been eliminated within 24 hours of application of a 4% zinc sulfite solution, with crusting occurring in 1-3 days and resolution soon to follow. Zinc’s topical use appears to be a safe and effective way to address cold sores, both in terms of prevention and treatment. In study, herpes lesions on the skin have been treated with zinc solution for 10 minute durations, while lesions in the mouth have been treated for 103 minutes once per day (hold solution in the mouth). [10, 11, 12]

Eugenol Eugenol, also known as 4-allyl-2-methoxyphenol, is a phenol compound that is derived from the oil of cloves. Eugenol is primarily used as a topical dental anesthetic. In Vitro studies of Eugenol have shown that it can inhibit the growth of the herpes simplex virus, as well as delay the onset of herpes induced keratitis in mice. It is possible that Eugenol could be used as an effective topical treatment for cold sores. Another effect of Eugenol is its anesthetic properties, which can help with the pain that is often associated with cold sores and other types of herpes outbreaks. [13]

Red Seaweed (Bostrychia montagnei and others) There are numerous studies on the effects of different types of red marine algae. Differing studies seem to indicate that these algae can be useful in the treatment and prevention of cold sore outbreaks. In fact, several extracts of the seaweed Bostrychia montagnei demonstrated significant inhibitory effects on herpes virus at concentrations that were nontoxic. There are several red algae products currently available for purchase as a dietary supplement. Depending on their potency, these products may be an effective combatant against herpes outbreaks. [14, 15]

Glycyrrhizic acid Glycyrrhizic acid is a derivative of the root found in the licorice plant (Glycyrrhiza glabra). The topical application of Glycyrrhizic acid for herpes lesions (cold sores) has been shown to inactivate the herpes simplex virus.. It is important to note that there are preparations of licorice root that are used in heartburn that have had the Glycyrrhizic acid removed due to its ability to raise blood pressure. These preparations are not effective against herpes simplex virus. [16, 17]

Lemon Balm (Melissa officinalis) Melissa is an herb with a refreshing lemony aroma. It has traditional uses that include calming the nervous system and treating hyperthyroid conditions. It has been demonstrated that a highly concentrated preparation (70:1) of Melissa, is effective against cold sores and other skin manifestations of Herpes simplex virus. In patients that were treated with a Melissa preparation, there was a shortened healing time, less likelihood of the infection spreading, and a reduction in specific symptoms, such as itching, tingling, burning, stabbing, swelling, and redness. [18]


[1] Beers and Berkow, The Merck Manual (Whitehouse Station, NJ: Merck Research Laboratories, 1999), 750-6.

[2] Fitzpatrick, Johnson, Wolff, Color Atlas and Synopsis of Clinical Dermatology (City: McGraw Hill, 1997), 792-809.

[3] Beers and Berkow, The Merck Manual (Whitehouse Station, NJ: Merck Research Laboratories, 1999), 1293-5

[4] Thein DJ, Hurt WC. Lysine as a prophylactic agent in the treatment of recurrent herpes simplex labialis. Oral Surg Oral Med Oral Pathol. 1984 Dec;58(6):659-66.

[5] Bartolotta S, Garcia CC, Candurra NA, Damonte EB.

Effect of fatty acids on arenavirus replication: inhibition of virus production by lauric acid. Arch Virol. 2001;146(4):777-90.

[6] Conroy, Yarnell, Berg-Nowicki, Naturopathic Approach to Ophthalomology and Otolaryngology (Wenatchee, WA: Healing Mountain , 2002), 248-51.

[7] McCune MA, Perry HO, Muller SA, O’Fallon WM.Treatment of recurrent herpes simplex infections with L-lysine monohydrochloride. Cutis. 1984 Oct;34(4):366-73.

[8] Hornung B, Amtmann E, Sauer G. J Gen Virol. 1994 Feb;75 ( Pt 2):353-61. Lauric acid inhibits the maturation of vesicular stomatitis virus.

[9] Bartolotta S, Garcia CC, Candurra NA, Damonte EB. Arch Virol.Effect of fatty acids on arenavirus replication: inhibition of virus production by lauric acid. 2001;146(4):777-90.

[10] Hovi T. Topical treatment of recurrent mucocutaneous herpes with ascorbic acid-contianing solution. Antiviral Research 1995;27:263-70.

[11] Eby GA, Halcomb WW. Med Hypotheses. 1985 Jun;17(2):157-65. Use of topical zinc to prevent recurrent herpes simplex infection: review of literature and suggested protocols.

[12] Wahba A. Topical application of zinc-solutions: a new treatment for herpes simplex infections of the skin? Acta Derm Venereol. 1980;60(2):175-77.

[13] Brody I. Topical treatment of recurrent herpes simplex and post-herpetic erythema multiforme with low concentrations of zinc sulphate solution. Br J Dermatol. 1981 Feb;104(2):191-4.

[14] Benencia F, Courreges MC. In vitro and in vivo activity of eugenol on human herpesvirus. Phytother Res. 2000 Nov;14(7):495-500.

[15] Bourne KZ, Bourne N, Reising SF, Stanberry LR. Plant products as topical microbicide candidates: assessment of in vitro and in vivo activity against herpes simplex virus type 2. Antiviral Res. 1999 Jul;42(3):219-26.

[16] Duarte ME, Noseda DG, Noseda MD, Tulio S, Pujol CA, Damonte EB. Inhibitory effect of sulfated galactans from the marine alga Bostrychia montagnei on herpes simplex virus replication in vitro. Phytomedicine. 2001 Jan;8(1):53-8.

[17] Serkedjieva J. Antiviral activity of the red marine alga Ceramium rubrum. Phytother Res. 2004 Jun;18(6):480-3.

[18] Hirabayashi K, Iwata S, Matsumoto H, Mori T, Shibata S, Baba M, Ito M, Shigeta S, Nakashima H, Yamamoto N. Antiviral activities of glycyrrhizin and its modified compounds against human immunodeficiency virus type 1 (HIV-1) and herpes simplex virus type 1 (HSV-1) in vitro. Chem Pharm Bull (Tokyo). 1991 Jan;39(1):112-5.

[19] Pompei R, Pani A, Flore O, Marcialis MA, Loddo B.

Antiviral activity of glycyrrhizic acid. Experientia. 1980 Mar 15;36(3):304.

[20] Dimitrova Z, Dimov B, Manolova N, Pancheva S, Ilieva D, Shishkov S. Antiherpes effect of Melissa officinalis L. extracts. Acta Microbiol Bulg. 1993;29:65-72.