Also indexed as: Zovirax Oral
Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem
contradictory. For clarification, read the full article for details about the summarized
| May Be Beneficial: Supportive
interaction—Taking these supplements may support or otherwise help your medication
Citrus root bark*
|Depletion or interference
|Side effect reduction/prevention
An asterisk (*) next to an item in the summary indicates that the
interaction is supported only by weak, fragmentary, and/or contradictory scientific
Interactions with Dietary Supplements
The flavonoids quercetin, quercitrin, and
apigenin enhanced the antiviral activity of acyclovir in test tube studies.1
Controlled research is needed to determine whether taking quercetin or other flavonoid
supplements would increase the effectiveness of acyclovir in humans.
Interactions with Herbs
The alkaloid citrusinine-1 from the root bark of citrus plants has been shown to enhance the
antiviral activity of acyclovir.2 Further research is needed to determine whether
taking citrus root bark would increase the effectiveness of acyclovir in humans.
Test tube studies show that triptofordin C-2 increases the antiviral activity of acyclovir
against the herpes virus.3
Controlled human research is needed to determine whether taking tripterygium would increase
the effectiveness of acyclovir in humans.
Animal studies have shown that other herbs, including Geum japonicum, Rhus javanica,
Syzygium aromaticum, and Terminalia chebula enhance the antiviral activity of
acyclovir.4 Controlled human studies are needed to determine whether taking these
herbs would increase the effectiveness of acyclovir in humans.
1. Mucsi I, Gyulai Z, Beladi I. Combined effects of flavonoids and
acyclovir against herpesviruses in cell cultures. Acta Microbiol Hung
2. Yamamoto N, Furukawa H, Ito Y et al. Anti-herpesvirus activity of
citrusinine-I, a new acridone alkaloid, and related compounds. Antiviral Res
3. Hayashi K, Hayashi T, Ujita K, Takaishi Y. Characterization of
antiviral activity of a sesquiterpene, triptofordin C-2. J Antimicrob Chemother
4. Kurokawa M, Nagasaka K, Hirabayashi T et al. Efficacy of traditional
herbal medicines in combination with acyclovir against herpes simplex virus type 1 infection
in vitro and in vivo. Antiviral Res 1995;27:19–37.