Pencivir is used for cold sores. It contains the active ingredient penciclovir, which is a so-called anti-viral drug, a drug to inhibit virus replication.
Cold sores are caused by the herpes simplex virus type 1. Genital herpes, on the other hand, is caused by type 2 herpes simplex viruses.
Pencivir is applied to the skin and can shorten the healing process. It also relieves the pain and itching of lip sores.

Indications for pencivir

The indications for pencivir are mild forms of cold sores, known as herpes labialis.
Pencivir can be used both in the early phase and in the vesicular phase.
This means that pencivir can be effective and accelerate the healing process even when itching and pain.
In fact, the earlier it is used, the more effective it is.

Use for cold sores

Cold sores usually run in several phases and usually last seven to twelve days.
Using pencivir can shorten this period.
Cold sores are often announced by itching, tingling or burning on the lip.
If possible, you should start using pencivir now, before the vesicle phase, in which fluid-filled vesicles appear.
In the process, the vesicles can burst and ooze, this phase is painful and highly infectious.

Pencivir can accelerate the formation of crusts and healing of the lip sores.
Cold sores are healed as soon as the crust dissolves on its own and healthy skin appears.

Read our article about the best ways to combat cold sores:
Cold Sores - How To Treat It Right

Effect and active ingredient

Pencivir contains the active substance penciclovir.
Penciclovir is an antiviral, a drug used to stop bacteria from multiplying.
Due to its structural similarity to their building blocks, it is embedded in the genetic information of viruses and prevents the virus from multiplying further.

In studies, penciclovir showed good tolerability and effectiveness.
Both the healing time and the pain associated with herpes were reduced by about a third.
The application also reduces the risk of infection, which is generally very high with cold sores.
Close contact and the exchange of saliva should nevertheless be avoided if possible.
The active ingredient has been approved in Germany since 1996.

Side effects

Pencivir is usually well tolerated.
It must not be used if there are allergies to acyclovir or drugs containing penciclovir.
This can lead to hypersensitivity reactions.
This includes the appearance of a rash, hives, itching or water retention, which can show up on the affected area, but also beyond.

When using pencivir, reactions of the treated skin areas such as burning, stinging or numbness occasionally occur.
In the event of severe side effects, the treatment should be discontinued and a doctor should be consulted.


There is no evidence of interactions with other medicinal products for pencivir.
Should a drug be prescribed, the doctor should be informed about the treatment with pencivir.

Contraindications - When should pencivir not be given?

Pencivir should not be used if there is hypersensitivity to penciclovir or aciclovir.
Pencivir should not be used on mucous membranes in the mouth.
Pencivir is not suitable for treating genital herpes.

Use in patients with a weakened or suppressed immune system is also contraindicated.
There is no information on the safety of the drug for use in children under the age of twelve; pencivir should not be used in these patients.


Pencivir should be applied at the first signs of illness such as itching or burning.
Then it shows the best effect in the therapy of cold sores.
Pencivir is usually applied to the affected area every two hours, but at least six times a day.
Pencivir should be applied thinly with a finger or a cotton swab, hands should be washed before and after applying the cream.

Excess amounts of the cream can be dabbed off with a cloth.
To prevent rubbing, it should be applied after eating.
Treatment with pencivir should be continued for four days, even if there is significant improvement.
If there is no improvement after the end of treatment with pencivir, see a doctor.


The price for 2 g Pencivir cold sore cream is between five and ten euros in Germany.
Pencivir can be obtained from pharmacies without a doctor's prescription.

Pencivir and alcohol - are they compatible?

Moderate consumption of alcohol does not affect the way pencivir works.
This is true if pencivir is continued to be applied thoroughly and at regular intervals.

Can it be taken during pregnancy and breastfeeding?

During pregnancy and breastfeeding, the benefits and risks of drugs should generally be carefully weighed.
Sufferers should consult their doctor every time they take medication.
The local use of pencivir in pregnant and breastfeeding mothers appears to be safe.
Infants and children should not have contact with the drug.

Does pencivir affect the way the pill works?

The local use of pencivir for cold sores does not affect the effectiveness of the pill.

What are the alternatives to pencivir?

In addition to penciclovir, the drug acyclovir is used in the treatment of cold sores.
Again, it is a virostat.

If you have shingles, you can use the drug Zostex®, which works specifically against these viruses and can be taken as an alternative.

Read more about this under: Zostex®

Some home remedies are also known as alternatives, including honey.
Tea tree oil is also recommended, but please note that this can be very irritating.
High-percentage alcohol from the pharmacy has a disinfecting effect and relieves itching and tingling.
Toothpaste should not be used, it dries out the skin and has no medicinal effect on cold sores.

Pencivir Or Acyclovir - Which Is Better?

Penciclovir or acyclovir are used for cold sores.
Penciclovir is the newer active ingredient and is more effective and tolerated than aciclovir.
Patients who use penciclovir are pain-free earlier and reach the so-called crust stage earlier.

Penciclovir also works if it is applied after the blisters appear.
Acyclovir does not seem to have any effect at this stage.

You can find more information about the antivirals acyclovir in our related article: Acyclovir

Pencivir in combination with Fenistil

The cream with the active ingredient penciclovir was previously available under the trade name Fenistil Pencivir, but now the product is simply called Pencivir.
Fenistil is a registered trademark of the pharmaceutical company Novartis.

Fenistil usually contains the active ingredient dimentinden, which is used for rashes, sunburns or insect bites.
It has anti-allergic effects.
The name change from Fenistil Pencivir to Pencivir prevents possible confusion for patients, the package and package insert clearly mark the indication for the use of the drug.