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Valtrex
(Valacyclovir)
Banish those blisters and get back to your best with Valtrex.
Strength
✓ IN STOCK
500MG
Quantity of tablets
28
$4.50/tablet
Shipment frequency
Every Month
Regular price
Every 3 Months
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Overview
WHAT IS VALTREX?
Valtrex contains the active ingredient valacyclovir and is a prescription medicine used to treat the herpes infections that cause cold sores (fever blisters) and genital herpes. Valtrex helps to make the symptoms of herpes infections less severe, less long lasting, and it can even prevent outbreaks from happening in the first place.
HOW DOES VALTREX WORK?
Valtrex is an antiviral medication that interferes with the growth of herpes viruses. It slows the spread of the virus through your body, helping your immune system to fight and clear it from infected cells. It can’t cure you of herpes entirely, as once you’ve been infected, herpes is with you forever. But it can prevent outbreaks from recurring and also help to clear up outbreaks of blisters faster, make them less itchy and painful.
HOW TO TAKE VALTREX
Valtrex is taken orally as a pill with water. How often you take it will depend on your infection and circumstances. Our doctors will determine the correct dosage for you, and you should always take the medicine as they direct.
FAQ
Valtrex is an antiviral medication containing the active ingredient valaciclovir. It works by stopping the herpes simplex virus from multiplying and spreading to other cells in your body. This gives your natural immune system the chance to control the infection. Valtrex can be taken at the first sign of an outbreak, but if you experience outbreaks regularly a daily suppressive treatment may be more suitable for you.
Valtrex can be taken by anyone over the age of 12. Check with us before taking Valtrex if you are over 65, have kidney or liver problems, or have a weak immune system. Do not take Valtrex if you’re allergic to valaciclovir or acyclovir, or any of the other ingredients listed in the leaflet enclosed with the medication.
Valtrex is taken orally as a pill with water. How often you take it will depend on your infection and circumstances. Our doctors will determine the correct dosage for you, and you should always take the medicine as they direct.
It can be taken as soon as the first symptoms of genital herpes or cold sores are felt, however you should seek advice from a doctor of healthcare professional in this instance.
FROM MARS provides Valtrex or valaciclovir as a daily preventative treatment for patients who have already been diagnosed with herpes, to help lessen the frequency of outbreaks and reduce the risk of transmitting the virus. The tablets should be taken as prescribed every day. It is important that you complete the course that is prescribed for you, even if it seems that the infection has cleared up.
It can be also taken as soon as the earliest symptoms are noticed during a persons first outbreak, however you will need to speak to a doctor or healthcare professional in this instance.
It depends on how severe your outbreak is, how quickly you take the medication after you notice the first symptoms, and the dose taken, but Valtrex typically works quickly and provides relief from symptoms within two to three days.
Don’t have sex if you have cold sores or blisters on your genitals or buttocks and the surrounding areas, or if you feel any other symptoms of an outbreak, such as the tingling sensation before the blisters form. The herpes viruses are highly contagious, and infections can be passed to others easily, even if you wear a condom. You can get back to sex after your treatment has finished and your outbreak has cleared up.
Valtrex can be taken once daily for long term preventative therapy of recurrent genital herpes.
Valtrex is generally a safe and well-tolerated medication, however, like all medications, there can be side effects. The most common side effects include headaches, nausea, diarrhea, a skin rash or sunburn after exposure to sunlight. Valtrex can also have an impact on your kidneys, so it is important to stay hydrated with water whilst taking this medication. For more information on side effects, please refer to the patient information leaflet.
Research has shown that the active substance in Valtrex, called valaciclovir, is better absorbed by your body when taken orally than medications that contain acyclovir. The research shows that Valtrex helps to clear up outbreaks of cold sores and genital herpes faster than if no medication is taken, that it can prevent blisters from forming, and that it can help provide relief from the pain and discomfort caused by the blisters.
Valacyclovir is the name of the drug itself, and Valtrex is a brand name under which the drug is often sold. If you see medication called Valtrex or valacyclovir, they’re medically the same.
Unfortunately, no. There is currently no cure for herpes simplex infections. Once the virus infects you it takes up residence in the nerve cells of your skin. The virus goes dormant there, effectively hiding from your immune system and avoiding any medication. The virus reactivates every now and then causing a new outbreak of blisters. Medications like Valtrex help to manage and shorten these outbreaks.
Valtrex also won’t completely stop the chances of you passing the virus onto other people. You should not let infected areas come into contact with other people, so you should avoid sex during an outbreak and remember to wash your hands regularly.
To find out more about the HSV 1 or HSV 2, please visit our cold sores or genital herpes pages. You’ll also find lots of advice and information about the conditions and our treatments on our blog.
Compare
VALACYCLOVIR VS VALTREX
Valtrex is a brand name medication discovered and marketed by GlaxoSmithKline, and valacyclovir is the active ingredient in Valtrex that treats cold sores.

Side Effects
Valtrex dosage and strength
The medication comes in 500 mg tablets. Always take the dosage advised and speak to us if you feel your recommended dose isn’t right.
Valtrex contraindications
DO NOT take Valtrex if:
- You are under the age of 12
- You are allergic to valacyclovir or acyclovir, or any of the other ingredients in the medication (see the leaflet in the Valtrex packaging for a full list of ingredients)
Check with our doctors if you:
- Are over 65 years old
- Have kidney problems
- Have liver problems
- Have a weak immune system
- Are pregnant or breastfeeding
Valtrex interactions
The following medications can interact with Valtrex. Tell our doctors if you are taking any of these, or if you plan to:
- Aminoglycosides
- Aprotinin
- Bictegravir
- Ciclosporin
- Cimetidine
- Cobicistat
- Colchicine
- Darunavir
- Doravirine
- Efavirenz
- Elvitegravir
- Emtricitabine
- Entecavir
- Foscarnet
- Fosphenytoin
- Hyaluronidase
- Iodinated contrast media
- Immune Globulin
- Lamivudine
- Measles, Mumps, and Rubella live vaccines
- Methotrexate
- Mycophenolate
- Organoplatinum compounds
- Pentamidine
- Phenytoin
- Probenecid
- Recombinant
- Rilpivirine
- Tacrolimus
- Talimogene Laherparepvec
- Telbivudine
- Tenofovir
- Tenofovir alafenamide
- Tenofovir disoproxil fumarate
- Varicella-Zoster Virus Vaccine
Taking other medications with Valtrex
Tell our doctors if you are taking, or plan to take, any other medications or herbal treatments at the same time as Valtrex. It’s important to let us know if this includes any of the medications listed above and any treatments for shingles, as well as medicines that affect the kidneys, or those that help after an organ transplant.
Who shouldn’t use Valtrex?
Children under the age of 12 shouldn’t take Valtrex. As an adult, you shouldn’t take this medication if you are allergic to valacyclovir or acyclovir, or any of the other ingredients in the medication (see the leaflet in the Valtrex packaging for a full list of ingredients).
How to take Valtrex
Valtrex usually comes in tablet form, which should be swallowed whole with a glass of water. The tablets should be taken at the same time each day, in the amount and for the duration prescribed. If you forget to take your Valtrex, take a dose as soon as you remember, unless it’s nearly time for your next dose. Never take two doses to make up for a missed one.
Driving and using machines
Valtrex has been reported to cause dizziness and headaches, so it’s important not to drive or use machinery if you experience these side effects.
Possible side effects of Valtrex
Like all medicines, Valtrex can have side effects. People respond differently to medications, some people will have no side effects, but some may experience any of the following:
Very common side effects (may affect more than 1 in 10 people)
- Headache
Common side effects (may affect up to 1 in 10 people)
- Sickness
- Sore throat
- Vertigo
- Dizziness
- Vomiting
- Diarrhea
- Constipation
- Rash
- Skin sensitivity to sunlight (photo-sensitivity)
- Itching (pruritus)
Uncommon side effects (may affect up to 1 in 100 people)
- Fatigue
- Shortness of breath (dyspnea)
- Stomach discomfort
- Rash, sometimes an itchy, hive-like rash (urticaria)
- Low back pain (kidney pain)
- Blood in the urine (hematuria)
Uncommon nervous system side effects (may affect up to 1 in 100 people)
- Confusion
- Seeing or hearing things that aren’t there (hallucinations)
- Feeling very drowsy
- Feeling agitated
- Tremors
Uncommon side effects that may show up in blood tests (may affect up to 1 in 100 people)
- A reduction of white blood cells (leukopenia)
- A reduction of blood platelets, the cells that help blood to clot
- An increase in substances produced by the liver
Rare side effects (may affect up to 1 in 1000 people)
- Kidney problems where you pass little or no urine
Rare nervous system side effects (may affect up to 1 in 1000 people)
- Impaired coordination and unsteadiness when walking (ataxia)
- Slow and slurred speech (dysarthria)
- Confusion and disturbed thoughts (delirium)
- Fits (convulsions)
- Changed in brain function (encephalopathy)
- Coma
Any nervous system side effects are more likely to occur in the elderly, and with people with kidney problems or who have recently had an organ transplant. These side effects usually diminish if they stop taking Valtrex or if the dose is reduced.
Side effects to look out for which indicate you’re having a severe allergic reaction (anaphylaxis)
- Flushing, itchy skin, and/or a rash
- Swelling of the lips, face, neck, and throat, making it difficult to breathe (angioedema)
- A rapid fall in blood pressure leading to collapse
The rapid onset of these symptoms indicates you’re having an allergic reaction to Valtrex. Valtrex allergies are rare, but if you do experience these symptoms stop taking the medication and seek urgent medical attention, as quickly as possible.
If you have any other concerns about the side effects of Valtrex, contact us.
How to store Valtrex?
Make sure you store Valtrex in its packaging, and in a cool, dry place with temperatures below 77°F. Always keep it out of reach and sight of children. Never use medication that has passed the expiry date displayed on the packaging. The expiry date refers to the last day of the month. Don’t throw expired tablets out with household waste, and don’t flush them down the sink or toilet, as they can cause harm to the environment. Take expired medications to your local pharmacy so that they can be disposed of safely.
If you have any further questions about Valtrex, contact FROM MARS.
Is valtrex safe?
Valtrex is a safe medication for most people over the age of 12 to use. There have been extensive clinical trials and it’s been used for over twenty years to fight herpes. All medications can have side effects though, and Valtrex isn’t suitable for everyone. If you experience any side affects you should stop taking the medication. We recommend reading the link below to understand all of the potential benefits and risks of the medication.
Info Leaflets
Before taking valtrex or any medication, it is important to read the Patient Information Leaflet.
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