Buy aciclovir tablets online
You can buy aciclovir tablets as long as they’ve been approved and prescribed by one of our clinicians.
Aciclovir is an antiviral medicine used to treat infections. We prescribe aciclovir 400mg tablets to treat genital herpes.
What is aciclovir used for?
Aciclovir tablets can be used to treat, and in some cases prevent conditions in people with a weakened immune system for:
- cold sores
- shingles
- chicken pox
- genital herpes
- herpes simplex eye infections
When aciclovir is prescribed as 400mg tablets, it can be used to treat skin infections like genital herpes, chicken pox or shingles.
However, Chemist4U will only prescribe 400mg to treat genital herpes.
If you’re looking for a cold sore treatment, then we also prescribe aciclovir 200mg tablets following a consultation.
How does aciclovir treat genital herpes?
As an antiviral medication, aciclovir works by targeting the herpes virus. To do this, it disrupts the DNA of the herpes virus, stopping it from multiplying and spreading. This means that your immune system is able to contain and fight the outbreak more easily.
Importantly, aciclovir will not get rid of the virus completely. There is currently no permanent cure for herpes.
How long does aciclovir 400mg take to work?
When taking 400mg tablets to treat genital herpes, you should notice the outbreak improve within a few days.
How effective is aciclovir 400mg?
Aciclovir is generally considered to be highly effective at treating genital herpes. However, it is not a cure.
Suppressive therapy has been found to reduce recurrences of genital herpes by 70-80% among patients who have frequent recurrences.
How to take aciclovir 400mg tablets
You should always take aciclovir tablets as soon as possible when you’re prescribed them. You can dissolve the tablet in water and drink it or swallow it whole with a small amount of water.
When taking aciclovir to treat an ongoing genital herpes infection you should:
- Take one 400mg tablets three times a day, for five days. You should wait roughly 6-8 hours between doses. We suggest: 7am, 1pm, 7pm.
If you experience six or more attacks per year, you can take 400mg tablets to suppress the infection. If you do, you should:
- Take 400mg twice daily.
- You should leave at least six hours between your doses.
You should not take the suppressive dose for longer than 12 months without a pause in treatment. This is to assess how likely the infection is to happen again.
How long should you take aciclovir for?
Generally, 400mg tablets are prescribed to be taken for five days. However, if it’s your first outbreak of genital herpes, then you may be advised to take them for longer.
If you’re prescribed aciclovir by a doctor, you should always follow the advice they have given you about how to use it and for how long.
Chemist4U does not prescribe for first time outbreaks. If it is your first outbreak, we recommend contacting your doctor or looking to get a diagnosis from a specialist or sexual health clinic.
What if I miss a dose?
If you miss a dose of aciclovir 400mg tablets, take it as soon as you remember, unless it’s nearly time for your next dose.
If it’s nearly time for your next dose, skip the dose you missed and take the next dose at the usual time. Do not take two doses to make up for one missed dose.
What should I do if I take too much?
Taking an extra aciclovir tablet is unlikely to cause problems, but if you are concerned that you have taken too much then you should speak to a pharmacist or a doctor.
Aciclovir side effects
Like all medication, aciclovir may cause side effects in some people. Common side effects can include:
This is not a complete list of side effects. For a full list of side effects, you should read the patient information leaflet.
Can you drink alcohol on aciclovir?
You can drink alcohol while taking aciclovir as it doesn’t interfere with the medication’s effectiveness. However, alcohol can cause dehydration, which can worsen side effects like dizziness and nausea.
When to avoid aciclovir
Most adults can use aciclovir to treat genital herpes but is not suitable for people who have had an allergic reaction to aciclovir or valaciclovir in the past.
Though you can usually use aciclovir if you are pregnant or breastfeeding, you should speak to a doctor or pharmacist first.
Aciclovir and other medications
Certain medicines may interact with aciclovir tablets, including:
- probenecid (a medicine used to treat gout)
- cimetidine (a medicine used to treat stomach ulcers)
- mycophenolate mofetil (a medicine you may need to take after having an organ transplant).
You should always tell your doctor or pharmacist about any medications that you are taking before starting aciclovir.
How to store aciclovir
Aciclovir tablets should be kept in below 25°C in a cool, dry place.
You should keep aciclovir out of the sight and reach of children, keeping away from direct sunlight and heat.
Alternatives to aciclovir tablets
Aciclovir tablets are not the only option to deal with genital herpes. There are other tablets available like Valtrex and its generic equivalent, valaciclovir.
If you don’t want to take tablets then you can consider aciclovir cream, following a consultation.
Sources
- Aciclovir. (2026). NHS. [Accessed on 5 March 2026]
- Genital Herpes. (2021). CDC. [Accessed on 6 March 2026]
- Aciclovir. NICE. [Accessed on 6 March 2026]
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Can you buy aciclovir over the counter?
You can buy aciclovir cream for cold sores over the counter at pharmacies. However, you need a prescription to get aciclovir tablets to treat genital herpes. You can get tablets via an online consultation with a pharmacy or your GP.
Can you have sex while taking aciclovir?
You should generally abstain from sexual activity while taking aciclovir tablets, especially while there are still active sores or blisters. Even after these have healed there is still a chance you can pass herpes on to your sexual partner.
