Valaciclovir is an antiviral medicine in the form of a tablet and a generic version of better known branded Valtrex. It is commonly prescribed as a treatment for herpes simplex virus (HSV) and has proven time and time again to be a very successful and efficient medicine for sending the virus back into remission. When properly used at the earliest sign of reactivation, it can dramatically reduce the severity of the outbreak and in some cases even prevent it altogether, before any symptoms have time to manifest.

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General information about herpes

Herpes is a term that is commonly used to refer to two different strains of the herpes simplex virus – herpes simplex type 1 and herpes simplex virus type 2 (HSV-1 and HSV-2). The former, HSV-1 is the known as the culprit for the appearance of cold sores around the mouth, while the latter is associated with genital herpes, a viral STI.

Herpes is a very contagious and persistent viral infection. When one gets infected, it is impossible to completely cure the condition and eliminate the virus from the body. However, the symptoms of herpes can be effectively managed and limited with the use of proper and timely applied medication. Those affected will commonly experience a cycle of flare-ups of the symptoms and periods of remission. In most cases, the symptoms will tend to decrease in both intensity and scope, but reactivations are not likely to disappear on their own – instead, they will have to be managed by antiviral medications in the early phases of the flare-up. Thus, similarly to many other viral infections, herpes too is a lifelong condition

Herpes simplex virus type 2 is transmitted through sexual contact, vaginal, oral or anal. Sharing of sex toys is also a significant risk factor. It manifests through appearance of sores and blisters at the site of the infection (genitals or anus). When active, that is, when symptoms flare up and are clearly visible, herpes is most contagious, although it can still be transmitted even during the periods of remission. However, if this is the case, the chances of spreading the infection are somewhat smaller.

Valaciclovir and herpes simplex treatment

The branded version of Valaciclovir, Valtrex, produced by the pharmaceutical company GlaxoSmithKline is very familiar in the medical community – this medicine established itself as one of the main go-to treatments for herpes and the same is true for the generic version. Officially, this medicine is classified as a prodrug, meaning it is not active in itself, but it gets converted into an active ingredient once it is processed by body’s natural metabolic processes. Once this happens, Valaciclovir will transform into a compound called acyclovir – a widely-used antiviral substance that is very common in different herpes medicines. It achieves its goal of limiting the spread of the infection and keeping the symptoms under control by supressing multiplication of the infected cells and effectively rendering the virus inert, thus making it an easy target for the immune system.

However, even with this reliable and highly successful mechanism of action, even Valaciclovir can’t cure the condition, but it can send it back into remission.

When should Valaciclovir be used?

If you are using Valaciclovir for management of herpes – that is, in case of recurrent outbreaks, you should start taking the medicine as soon as you notice the early signs and symptoms. Some people might notice weakness and general malaise even before blisters and sores appear – if that is a common pattern for you, that this might be a good sign that you should start using Valaciclovir.

Can I buy Valaciclovir online?

If you just found out you have been infected and it is your first time using Valaciclovir, it will be necessary for you to first confirm your diagnosis if you haven’t already and then obtain the prescription. The conventional way to do this would include visiting your doctor or general practitioner and consulting with him, or arranging an examination at your local GUM or STI clinic. Once you are examined and tested for STI, the practitioner will give you instructions and provide you with a prescription needed to obtain the treatment at your local pharmacy.

Another option that is increasingly popular these days is an online clinic. Not only will you save time that you would otherwise spend waiting at the clinic or in line at the pharmacy, but you will also avoid those uncomfortable conversations and face-to-face meetings. Not only can you obtain your medicine online this way, but you can also buy an at-home STI testing kit. To use the kit, you will be required to collect urine samples and genital swabs using the provided tools and sending these samples to a certified laboratory via post office. Once the results are in, you will be informed via the communication channel of your choice. With confirmation from the laboratory you can then again use the online clinic to consult with the doctor and notify him about your results. If the use of Valaciclovir is not contraindicated for some reason, the doctor will issue the prescription and instantly use it to send the medicine to be delivered to your doorstep.

On the other hand, if you simply need to renew your prescription, the results of the first STI test where you tested positive for herpes and online consultations with a doctor (usually via customized questionnaire) will be enough for a new prescription.

Valaciclovir as a generic medicine

The success of Valaciclovir is based on its active ingredient of the same name. Originally, it was developed and marketed by GlaxoSmithKline as Valtrex in the late 1980s, while it became available as a generic medicine in 2009, when the patent expired. As with all generic medicines, Valaciclovir has a proof of bioequivalence with the original, meaning it contains the same active ingredient in the same concentration and was designed for the use in the treatment of same conditions, with same results and same possible side effects.

How to use Valaciclovir?

  • Always take as prescribed by your doctor or pharmacist
  • Usual dose for genital herpes is one tablet two times per day
  • The duration of the treatment is five consecutive days for recurrent outbreak and ten consecutive days for initial infection
  • Take the tablet whole with water
  • You don’t have to take tablets with food, but you can if you prefer
  • Do not exceed the prescribed amount
  • If you miss a dose, do not take a double one afterwards – just continue the treatment as usual

What are Valaciclovir side effects?

Frequency of occurrence Side effects
Common (1 in 10 users)


Headache, nausea
Uncommon (1 in 100 users)


Rash, over-sensitivity to light, breathlessness
Rare (1 in 1000 users)


Confusion, dizziness, diarrhoea, kidney dysfunction, abdominal pain, vomiting
Very rare (1 in 10.000 users)


Angioedema, kidney failure, tremors, ataxia, convulsions

Is it safe for me to use Valaciclovir?

As is the case with all medicines, there are some situations when the use of Valaciclovir might be contraindicated. This can happen if there is a possibility of an adverse interaction with another treatment you might be taking at the same time or if you have a pre-existing condition that might make Valaciclovir dangerous for you. This is why it is important to disclose all the relevant information to your doctor during consultations.

Valaciclovir interactions

Valaciclovir has been known to interact with the following medicines:

  • Probenecid
  • Cimetidine
  • Tacrolimus
  • Ciclosporin
  • Mycophenolate mofetil

Medical conditions as risk factors

You shouldn’t use Valaciclovir if you have a history of liver or kidney disease. In addition to this, this product is also not recommended for women who are pregnant, are trying to conceive or who might be currently breastfeeding.