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Aciclovir Tablets 400mg

From £9.89 See Prices

⭐Discreet delivery
⭐Well-tolerated with minimal side effects
⭐For the treatment and prevention of genital herpes

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  • Plain & Discreet Packaging Plain & Discreet Packaging
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  • UK registered service UK registered service
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Aciclovir PRICES

Medicine x15 Tablets x30 Tablets x45 Tablets x180 Tablets
Aciclovir 400mg Tablets £9.89 £19.49 £23.89 £43.95

About aciclovir tablets

Key points

  • Aciclovir is an antiviral treatment, available on prescription only
  • To treat a genital herpes outbreak, take aciclovir 400mg three times a day for 5 days
  • To reduce the number of outbreaks, take aciclovir 400mg two times a day long-term
  • It can take 1-2 days for aciclovir to start working


Buy aciclovir online

You can buy aciclovir online by completing a short medical questionnaire. One of our pharmacists will screen the answers, to make sure that treatment is safe for you to take. All purchases are shipped from our UK pharmacy, with next-day delivery options available.

What is aciclovir used for?

Aciclovir is an antiviral medication, used to treat infections which are caused by the herpes virus. These include:

  • Genital herpes
  • Cold sores
  • Shingles
  • Chickenpox
  • Eye infections


Genital herpes

Genital herpes is an infection caused by the herpes simplex virus. It causes sores to develop around the vagina, or the penis. Sores can also develop around the thighs and anus. Not all sores around the genitals are herpes, and you should get testes for herpes, before using treatment.

Aciclovir can be used to reduce the length and severity of an outbreak.

Aciclovir tablets can also be taken long-term, to reduce the number of outbreaks in those that experience herpes outbreaks on a regular basis.

How does aciclovir work?

Aciclovir works by changing the DNA of the herpes simplex virus, so that virus is unable to multiply and infect more cells. This allows the immune system to bring the virus under control, resulting in fewer and milder symptoms that disappear faster than they would without treatment.

Important note: aciclovir is not a cure for infections, but rather can help sores to heal faster and prevent new sores from developing. Treatment can also be effective in reducing pain and itching after sores have healed, reducing the risk of the virus spreading to different parts of the body. 

Aciclovir dose instructions

Genital herpes outbreak dose

Take one aciclovir 400mg tablet, three times a day for 5 days.

Genital herpes suppression dose

Take one aciclovir 400mg tablet, two times a day. You should review your treatment after 6-12 months to see if the number of outbreaks has reduced. 

Important note: Spread the dose evenly throughout the course of the day.


How to take aciclovir tablets

  • You should take one tablet with a glass of water, spacing your doses evenly throughout the day. If you have trouble swallowing tablets, you can disperse tablets in water. 
  • If you take aciclovir three times a day, you should space the doses evenly, taking one tablet in the morning, afternoon, and evening. 
  • If you take aciclovir twice daily, you should take one tablet in the morning, and one in the evening. 
  • If you miss a dose of aciclovir, you should take it as soon as you remember. However, if it is nearly time for the next dose, take the dose at the set time, rather than taking a double dose. 
  • You should continue using the treatment until you have completed the course, even if you are feeling better after a few days of taking the medication. Treatment for an outbreak will usually last five days, whilst treatment for genital herpes suppression is ongoing. 
  • It is important to drink plenty of water, to avoid dehydration. This will ensure that less stress is placed on your kidneys, avoiding any potential side effects and damage to kidneys. 

Aciclovir tablets side effects

Side effects are usually mild and disappear as you adjust to taking the medication.

Side effects of aciclovir tablets include:

Common (affecting up to 10% of users):

  • Dizziness
  • Headache
  • Nausea
  • Diarrhoea
  • Stomach ache
  • Skin sensitivity after light exposure
  • Itchiness
  • Fatigue
  • High temperature
  • Feeling faint


Uncommon (affecting up to 1% of users):

  • Hair loss


For a full list of side effects, refer to the patient information leaflet.

Stop taking aciclovir tablets and seek urgent medical attention if you experience signs of an allergic reaction such as:

  • Rash or very itchy skin
  • Swelling of the face, mouth, lips, tongue, eyes, throat, or any other part of your body
  • Difficulty breathing or shortness of breath
  • Collapse


Always report any side effects to your doctor or pharmacist.

Aciclovir ingredients

Active ingredients: Aciclovir 400mg

Inactive ingredients: Magnesium stearate, colloidal anhydrous silica, sodium starch glycollate, polyvidone, E172 and E460

Important note: Whilst the active ingredient will always remain the same, different manufacturers may use alternative inactive ingredients. This will not impact the effectiveness of treatment.

Aciclovir warnings

You should not take aciclovir if you:

  • Are over 65 years of age
  • You have kidney problems
  • You have a condition that affect the immune system such as HIV
  • You have a condition which affects the nervous system
  • You have any allergies to aciclovir or its ingredients


Can you drink alcohol with aciclovir tablets?

There is no direct interaction between aciclovir and alcohol, so you can drink in moderation whilst using treatment. However, if you are experiencing side effects, limit your consumption, as alcohol may intensify side effects of aciclovir, such as headaches, nausea, dizziness, and sleepiness. 

Excess alcohol can reduce the function of your immune system. To get the most out of your treatment, alcohol consumption should be limited. 

Aciclovir and pregnancy

It is safe to take aciclovir tablets during pregnancy, but this should be done under the supervision of your doctor. It can be advised to take aciclovir four weeks before birth to prevent a genital herpes outbreak. This is to prevent the infection from being spread during birth. 

If you have herpes and are pregnant, the risk of passing it onto your baby is very low, however, you should make your doctor aware so that you can discuss your options. 

Aciclovir and breastfeeding

A small amount of aciclovir is present in breastmilk, and you should avoid taking it unless the benefits outweigh the risks.

You may still be eligible to use treatment, however, this is done under the supervision of your doctor.

Aciclovir interactions

You should avoid the following medication when taking aciclovir:

  • Cimetidine – used to treat stomach ulcers
  • Probenecid – used to treat gout
  • Mycophenolate mofetil – used to stop the body rejecting an organ after a transplant
  • Theophylline and aminophylline – used to treat asthma and breathing conditions


Important note: Always inform your doctor or pharmacist if you are taking medication, so that they can check for interactions.

Aciclovir alternatives

Aciclovir vs valaciclovir

  • According to clinical studies, both aciclovir and valaciclovir have similar results
  • To treat an outbreak, aciclovir is taken three times a day, whereas valaciclovir is taken two times a day
  • For suppression therapy, aciclovir is taken two times a day and valaciclovir is taken once a day
  • Aciclovir is cheaper than valaciclovir


Aciclovir tablets vs aciclovir cream

  • Both aciclovir tablets and aciclovir cream can be used to treat cold sores
  • Aciclovir tablets can be used to treat genital herpes, whereas aciclovir cream is not licensed as a genital herpes treatment
  • Aciclovir tablets are more effective than the cream


  1. British National Formulary. (n.d.). Aciclovir. Retrieved February 26, 2024, from

  2. NHS UK. (n.d.). Aciclovir. Retrieved February 26, 2024, from

No, you cannot buy aciclovir tablets over the counter. You will need a prescription to buy aciclovir in the UK.

You can order aciclovir online from a registered pharmacy, such as Chemist Click. A pharmacist will assess your suitability through an online consultation and generate a prescription in-house if it is safe to do so. Your medication will be dispensed and dispatched to you in plain and discrete packaging. 

Aciclovir cream is only licensed to treat cold sores (oral herpes), but not genital herpes.

Yes, aciclovir can be taken to treat shingles. The dose of aciclovir used to treat shingles is different to the dose used to treat genital herpes.

It can take 1-2 days for aciclovir tablets to work.

Yes, aciclovir is available on the NHS.

Yes, painkillers such as ibuprofen and paracetamol are safe to take alongside aciclovir tablets.

Yes, aciclovir is available in liquid form, however, it is more expensive than the tablets. Many forms of aciclovir tablets are dispersible.

Yes, but it is important to remember that it is still possible to pass the infection on to others. The chances of transmitting herpes to somebody else increases during an outbreak.

If you experience less than six outbreaks a year, your best option would be to use aciclovir each time you have an outbreak. 

If you experience six or more episodes of genital herpes a year, you may wish to think about taking aciclovir as suppression therapy. This can reduce the number of outbreaks.

If you are experiencing less than six outbreaks a year, but you feel as though herpes is negatively affecting your mental health, you should speak to your doctor or pharmacist about using suppression therapy. 

Product Reviews For Aciclovir Tablets 400mg


On the whole, those who buy aciclovir tablets have given the medication positive feedback for its ability to treat outbreaks of herpes, shingles and chickenpox. Users who stick with the course of aciclovir as advised have praised the medication’s effectiveness in lessening the seriousness of viruses, especially when it is taken within 72 hours. There are a large number of reviews that cite the effectiveness of clearing up infection breakouts that involve cold sores. For the duration that aciclovir is taken, many users report their herpes breakouts cleared quickly and did not return. 

Others with sores or blisters reported that although aciclovir didn’t prevent them from forming altogether, it was effective in reducing the size of the blisters or sores and making them less painful. 

While some users reported no side effects, others do notice feeling a little different when they first begin taking aciclovir.  For a more in-depth review of this medication, take a look at our page dedicated to aciclovir tablets review.

If you are interested in finding out more about genital herpes in general, take a look at some of the following articles:

Summary For Aciclovir Tablets 400mg

Medication class Oral antiviral
Mechanism of action Stops the virus from replicating, reducing symptoms
Active ingredient Aciclovir
Strength 400mg
Effective within 24-48 hours
Dosage instructions

One tablet three times a day (outbreak treatment)

One tablet twice a day (suppression treatment)
Manufacturer Actavis, Ranbaxy, Crescent, Wockhardt, Milpharm, Teva
Use with alcohol In moderation

See over 18 product reviews

Product rated 5/5

Aciclovir Tablets 400mg
Affective relief

By Gary Winder, 03rd of April

Aciclovir Tablets 400mg
this product done the trick

By Sam Hannell, 26th of December

Aciclovir Tablets 400mg
product has helped will purchase more in the future

By Sam Hannell, 10th of December

Aciclovir Tablets 400mg
If I don't take this,then I will have to suffer with outbreaks very much so.

By ADRIANA MOLDOVAN, 05th of September

Aciclovir Tablets 400mg
Do the job

By Anna, 23rd of August

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