Aciclovir Cream for Herpes

Medically reviewed by
Dr Brenda IkejiLast reviewed: 21 Apr 2025
Aciclovir cream is an effective and widely used treatment for herpes outbreaks (aciclovir tablets may also be prescribed for shingles and chicken pox). If you feel a cold sore or a flare-up of genital herpes coming on, applying aciclovir cream can help speed up recovery and reduce discomfort.
If you want to try aciclovir cream for herpes, you can find out more information in this guide on how to use it, how effective it is, potential side effects, and other treatment options.

Key takeaways
Aciclovir cream is a cream for treating infections caused by the herpes virus. It can heal symptoms of a recurrent herpes outbreak in around 4 days, compared to 7 to 10 days without.
Aciclovir cream is easy to use but does have some disadvantages too. There are some risks to using aciclovir cream, including side effects.
Aciclovir tablets require a prescription but can treat more severe infections than creams and can prevent outbreaks.
What is aciclovir cream used for?
Aciclovir cream is an antiviral medication used for treating herpes infections. It’s a topical cream, meaning it is applied to the skin of the infected area.
You’ll need a prescription from a doctor if you need aciclovir cream for genital herpes. If you have herpes affecting the mouth or face (cold sores) you can buy it over the counter.
If you notice an outbreak of herpes starting to happen (early signs are usually tingling, burning, or itching), you should apply aciclovir cream directly to the affected area several times per day. It makes herpes outbreaks shorter compared to not using treatment. It can also make your symptoms less severe.
If you’re unsure whether or not you have herpes, it’s important to do a herpes test. Your doctor will want to diagnose your condition before they’ll prescribe aciclovir.
Is aciclovir the best cream for treating herpes sores?
Creams containing the antiviral aciclovir are the best option for treating herpes. Aciclovir cream can heal symptoms of a recurrent herpes outbreak in 4 days on average, compared to 7 to 10 days without.
If creams containing aciclovir are not suitable for you, your doctor or a pharmacist may suggest other antivirals, such as Fenistil (which contains the active ingredient penciclovir).

“Aciclovir cream can be an effective treatment if you experience cold sores or milder genital herpes outbreaks. Studies show that on average it can make an outbreak go away 3 to 6 days sooner than without treatment, and your symptoms are less likely to be severe. However, aciclovir cream is not a cure and does not stop transmission so you must avoid sexual contact until your treatment course has ended.” – Dr Brenda Ikeji, Medical Editor
What dosage does aciclovir cream come in?
The cream is available in a strength of 5%, which means there is 5g of the active ingredient, aciclovir in 100g of cream.
How does aciclovir cream work?
Aciclovir cream works for herpes because the active ingredient disrupts the DNA of the herpes virus (type 1 and 2). This prevents the virus from replicating itself and spreading, allowing your immune system to suppress the outbreak more easily. However, it will not get rid of the virus completely and there is currently no permanent cure for herpes.
When should you use aciclovir cream?
You should start using aciclovir cream at the first sign of an infection (for instance when you first start feeling your skin tingling). It’s best to start using it at this stage before the cold sore or blisters are visible, as treatment is more effective. You can use it once they have appeared but the cream may not always work.
How to apply aciclovir cream
- Wash your hands thoroughly with soap and warm water before applying.
- Take a small amount of aciclovir cream on your fingertip – you must not mix the cream with anything else, not even water. Apply a thin layer to the affected area by rubbing it on gently, making sure the whole of the affected area is covered.
- Wash your hands after applying the cream, and make sure you place the lid of the cream on tight and put it back safe in its packaging.
After applying aciclovir, we recommend that you do not:
- wash the cream off by bathing, showering, or swimming straight after
- cover the area with plastic or waterproof plasters unless advised by your doctor
How often should you apply aciclovir cream?
When you use aciclovir cream for genital herpes or a cold sore, it should be applied 5 times per day, roughly 4 hours apart.
How long should you use aciclovir cream for?
If you are using aciclovir for a cold sore, you should use it for at least 4 days. If it has not gone away in that time, you can still use it for another 6 days. But if the cold sore still has not gone away after 10 days, speak to your doctor.
If you’re using aciclovir for genital herpes, you should use it for at least 5 days. If the outbreak has not gone away after five days, you can still use it for 5 more days. If it has not gone away after 10 days, speak to your doctor.
You should use the cream within 4 weeks of opening the tube. If you have an older tube that you used in the past (more than 4 weeks ago), it is better to order a new tube.
What if you forget to apply aciclovir cream?
If you forget to use the cream, use it as soon as you remember and continue as before.
However, if it is nearly time for your next application, then skip the missed application. You should never ‘double dose’ by applying more to make up for a missed dose.
Things to avoid when using aciclovir cream
- The cream should never be used in the eyes, or inside the mouth, vagina, or penis.
- Never give the cream to anyone else, even if their symptoms are the same as yours.
- Do not use a double application to make up for a missed application.
- Do not use more than the recommended dose.
- Do not refrigerate the cream.
What are the advantages and disadvantages of using aciclovir cream?
The advantages of using aciclovir cream are that it:
- is easy to use
- is conveniently available over the counter for cold sores, though a prescription is needed for genital herpes
- has a low risk of side effects
The disadvantages of using aciclovir cream are that it:
- cannot be used to prevent or suppress herpes recurrences
- cannot treat a herpes infection which is inside your mouth
- might be inconvenient to apply 5 times per day
What are the side effects of aciclovir cream?
For the majority of people, aciclovir cream is a safe and effective treatment, but like any medication it can cause side effects for some people.
The most common side effects include:
- drying or flaking of the skin
- short term stinging or burning of the skin
- itching
Rare aciclovir side effects include:
- redness of the skin
- contact dermatitis – a type of eczema (this is mostly caused by the other ingredients in the cream rather than from aciclovir itself)
Aciclovir cream should never be used if you are allergic to it or if you’ve ever had an allergic reaction to another antiviral called valaciclovir. You should also never use aciclovir if you are allergic to propylene glycol, cetyl alcohol, or any other ingredients present in aciclovir cream.
When to seek medical help for aciclovir side effects
If you experience an allergic reaction causing swelling of the lips, face, or neck leading to severe difficulty in breathing, or severe skin rash or hives, stop using the cream. This is a very serious and potentially dangerous side effect. Call 999 or go to the nearest A&E department for treatment.
What happens if you apply too much aciclovir cream?
There is a very low risk of overdose with aciclovir cream but you should always stick to the dose recommended by your doctor. There is a greater risk of overdose with aciclovir tablets as they contain higher dosages. Overdose can cause stomach pain, headache, or confusion. Speak to your doctor urgently if you are concerned about overdosing.
How does aciclovir cream compare to tablets?
Aciclovir cream and tablets are used to treat different kinds of herpes outbreak.
Aciclovir tablets can be used for recurrent cold sore outbreaks, herpes infections inside your mouth, genital herpes, and more severe infections. Tablets are also prescribed to prevent the virus from spreading to other parts of the body where it can cause more severe infections in people with weak immune systems. There are also different dosages of the tablets available that are prescribed depending on how severe your infection is.
The main aciclovir cream uses are for cold sores and milder outbreaks of genital herpes.
When comparing aciclovir cream vs tablets to treat your herpes, your doctor will assess different factors to decide which treatment may be right for you.
Aciclovir tablets have certain advantages as they:
- treat more severe infections
- are prescribed for both treating or preventing herpes recurrences
- treat herpes infections inside the mouth and recurrent cold sore outbreaks
- can be adjusted in dose if you are unable to tolerate a dose or if your infection does not respond
- may be more effective at treating genital herpes than creams
There are, however, disadvantages that come with using herpes tablets:
- they are not readily available over-the-counter
- there is a higher risk of side effects, especially in elderly people and those with kidney impairment
- there is a higher risk of interactions with other medicines
- they may cause drowsiness as a side effect that can affect your ability to drive or operate heavy machinery
- you must keep well hydrated by drinking plenty of water while taking them
Can you use aciclovir cream and tablets together?
There is no benefit to using aciclovir cream and tablets at the same time. Clinical research has shown that when combined, the treatment is no more effective than when either tablets or creams are used on their own.
Are aciclovir tablets better than cream?
It’s not possible to say that aciclovir tablets are ‘better’ or ‘worse’ than aciclovir cream. Each treatment has certain strengths and limitations, which might make it more or less suitable, depending on your situation and treatment needs.
In some cases, aciclovir tablets are the more suitable treatment. For example, someone having a severe outbreak of genital herpes will benefit from stronger tablets. Similarly, a herpes outbreak inside the mouth cannot be treated with a cream, so a tablet would be the right option.
In other situations, a cream might be a more suitable option. For example, a mild cold sore on the face or on the genitals can be conveniently treated with a cream. Creams tend to have fewer side effects than tablets too.
Where can you buy aciclovir cream?
You can buy a form of aciclovir cream for cold sores (on your lips and face) over the counter at local pharmacies. You cannot buy aciclovir cream for genital herpes without a prescription.
You should not use the version of aciclovir that’s meant for cold sores on genital herpes. It’s not intended for use on this part of your body, it may be weaker, and will not work as effectively as aciclovir cream that’s designed specifically for use on genitals.
How else can I manage cold sores?
You can manage your cold sore when you have an outbreak by avoiding:
- direct physical contact with people, such as kissing
- sharing items that can pass on the virus such as cups, cutlery, make up or lip balm – you can still use communal facilities such as showers, toilets, or swimming pools
- participating in oral sex
- limiting possible stressors that may trigger outbreaks
How can I manage genital herpes?
Do not have sex during an outbreak of genital herpes or during the initial signs of an outbreak.
Reduce the risk of passing it to partners by:
- using a condom if you have been diagnosed with herpes but have no symptoms (the virus can still be passed on from direct skin contact to your partner despite the use of a condom)
- not allowing anyone to come into direct contact with your sores or blisters
- washing sex toys thoroughly before using them and/or putting a condom on them

Brenda studied medicine at St Georges University of London and has most recently worked in John Radcliffe Oxford University Hospitals, covering acute and general medicine.
Meet our doctorsLast reviewed: 21 Apr 2025
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