Aciclovir (Zovirax) in Spain: Cream vs Tablets
Medically Reviewed by Dr. Pedro Yelamo Vera, MD
Licensed Physician No. 484814280 · Official Medical College of Bizkaia (Spain)Last reviewed: 21 October 2026
Aciclovir is the antiviral known as Zovirax. In Spain the small cold-sore cream is over the counter; tablets need a prescription. What each form treats.
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Dr. Pedro Yelamo Vera is an independent, bilingual GP licensed in Spain. Book a 15-minute video consultation in English or Spanish for €50, with a private electronic prescription issued under Spanish law when clinically appropriate.
Aciclovir (spelt acyclovir in the US) is the antiviral medicine many people know as Zovirax. In Spain you will mostly see it as aciclovir, often a generic. The small cream for cold sores is sold in pharmacies without a prescription. Tablets, and the larger cream tubes for genital herpes, need a prescription from a doctor.
- Aciclovir treats infections caused by herpes viruses: cold sores, genital herpes and shingles.
- The 2 g cold-sore cream is over the counter in Spain. Tablets are prescription-only, as are the larger cream tubes.
- Cream helps a little with a cold sore if you start at the first tingle. Tablets are the treatment for genital herpes, shingles and severe or frequent outbreaks.
- Herpes near the eye, or any outbreak with fever, a bad headache or confusion, needs urgent care. In an emergency, call 112.
Dr. Pedro Yelamo Vera is a GP licensed in Spain (Colegiado No. 484814280).
For a medical emergency, call 112 or go to the nearest local emergency department. Do not wait for a video consultation or an online reply.
What is aciclovir (Zovirax) used for?
Aciclovir slows down the herpes family of viruses while your immune system clears the outbreak. It does not remove the virus from the body, so outbreaks can come back. It is used for:
- Cold sores (herpes labial) on the lips and around the mouth.
- Genital herpes, both the first episode and repeat outbreaks.
- Shingles (herpes zóster), the painful blistering rash caused by the chickenpox virus.
- Chickenpox in adults and in people at higher risk, and some herpes infections of the eye or in people with a weak immune system, under specialist care.
In Spain the Zovirax brand exists, but pharmacies far more often stock generics labelled aciclovir, and cold-sore creams under their own brand names. The leaflet will always list aciclovir as the active ingredient. If you came from the UK or the US, it is the same molecule as Zovirax.
Cream or tablets: what is the difference?
The cream works only on the skin where you put it. It is for cold sores and for mild genital outbreaks. It shortens a cold sore by about a day at best, and only if you start at the first tingle, before the blister forms. Once the blister is out, it adds little.
Tablets (and the liquid for children) work through the whole body. They are the treatment for genital herpes, for shingles, for chickenpox in adults and for cold sores that are severe, frequent or keep coming back. Shingles tablets work best when they are started within about three days of the rash, so do not wait.
Some people with frequent genital outbreaks take tablets every day to prevent them. That is a decision for your doctor, and it is reviewed over time.
What can a Spanish pharmacy sell you without a prescription?
The aciclovir cream in a 2 g tube for cold sores is a non-prescription medicine in Spain (the leaflet says este medicamento puede adquirirse sin receta). Ask for crema para el herpes labial or aciclovir crema. The pharmacist can also offer patches and other over-the-counter products for cold sores.
The larger cream tubes (15 g, indicated for genital herpes) and all aciclovir tablets are prescription-only (con receta). The same goes for valaciclovir and famciclovir. A pharmacy cannot sell you tablets on the strength of a foreign prescription or an old box. You can check the status of any presentation on the AEMPS CIMA database.
Our cold-sore page explains what a doctor can do when cold sores are frequent or severe.
What are the best evidence-based antiviral treatments for herpes, and how do you choose between them?
Three antivirals have solid evidence for herpes simplex and shingles: aciclovir, valaciclovir and famciclovir. They work the same way and are about equally effective. Valaciclovir is turned into aciclovir in the body and is absorbed better, so it is often chosen for convenience. The choice depends on where the infection is, how often it comes back, your kidney function, pregnancy, your age and what is available. A doctor makes that call; none of the three is "stronger" than the others.
A few points that guide the choice:
- Site: cream for a simple cold sore; tablets for genital herpes, shingles and the eye area.
- Timing: all of them work best when started early. A tablet started late in a mild cold sore may add nothing.
- Frequency: six or more genital outbreaks a year is a usual trigger to discuss daily preventive treatment.
- Kidneys: the dose of all three is adjusted when kidney function is reduced, so tell the doctor about kidney disease.
Frequent cold sores, a possible shingles rash, or not sure which form of aciclovir applies to you?
You can book a video visit with a GP licensed in Spain, in English or Spanish. He reviews the outbreak and tells you whether a prescription is right for you.
Who should check with a doctor first?
- Pregnant or breastfeeding: aciclovir has a long safety record and is often used in pregnancy, but the decision is the doctor's. Genital herpes late in pregnancy needs a plan for the birth.
- Kidney disease or dehydration: tablets need care and dose adjustment.
- A weak immune system (chemotherapy, HIV, transplant medicines): outbreaks can be worse and need prompt treatment.
- Children under two with a cold sore, and babies with any blisters, should be seen by a doctor.
Side effects
The cream can sting or dry the skin a little. Tablets are usually well tolerated; the most common effects are headache, nausea and diarrhoea. Rarely, high doses or dehydration can affect the kidneys, which is why you are told to drink enough. Confusion or shakiness in an older person taking tablets should be reported to a doctor.
When to see a doctor
- Blisters or redness near the eye, or any eye pain with a herpes outbreak. Herpes in the eye can damage sight.
- A rash that may be shingles, especially on the face. Early tablets matter here.
- A first genital outbreak, or outbreaks that keep coming back.
- A cold sore that lasts more than ten days or is spreading.
- Anyone with a weak immune system and a new outbreak.
When to call 112
- A herpes outbreak with a severe headache, stiff neck, drowsiness, confusion or a seizure.
- A widespread blistering rash in a baby, or in anyone with a very weak immune system, who is unwell.
- Swelling of the face, lips or throat, or trouble breathing after taking the medicine.
Talking it through with a doctor by video
Dr. Yelamo is a GP licensed in Spain. He sees adults, children and pregnant patients by video, every day from 07:30 to 20:30 (Spain time). In the visit he will:
- Look at the sores or rash on camera and ask when they started.
- Ask about past outbreaks, pregnancy, kidney problems and other medicines.
- Explain whether cream, tablets or no antiviral is the right step.
- Tell you if you need to be seen in person, for example for an eye problem or shingles on the face.
He does not promise any test or prescription before the visit. Where clinically appropriate, following a genuine evaluation. Treatment and prescriptions are issued solely at the doctor's discretion based on evidence-based clinical guidelines.
A prescription is never guaranteed: it is issued only where clinically appropriate after a genuine evaluation, as a private electronic prescription under Spanish law. This service is for urgent, non-emergency care. In an emergency, call 112.
See how the Urgent Care video visit works. It lasts 15 minutes and costs €50.
This guide is general information. It does not replace the package leaflet or the advice of your doctor or pharmacist.
Frequently asked questions
Is Zovirax the same as aciclovir?
Yes. Zovirax is a brand name; aciclovir (acyclovir in the US) is the active ingredient. In Spain you will mostly see generic aciclovir and cold-sore creams under other brand names.
Can I buy aciclovir cream in Spain without a prescription?
Yes, the 2 g cold-sore cream is a non-prescription medicine in Spanish pharmacies. The larger tubes for genital herpes and all aciclovir tablets need a prescription.
Do I need tablets or cream for a cold sore?
A simple cold sore needs cream at most, started at the first tingle. Tablets are used when cold sores are severe, frequent or in someone with a weak immune system, and a doctor decides.
Does aciclovir cure herpes?
No. It shortens and eases an outbreak and can prevent outbreaks when taken daily, but the virus stays in the body.
Can I use aciclovir in pregnancy?
Aciclovir is often used in pregnancy when there is a good reason, because it has a long safety record. Ask a doctor rather than self-treating, especially for genital herpes.
What if I have shingles?
See a doctor quickly. Tablets work best when started within about three days of the rash, and shingles near the eye needs urgent in-person care.
Sources
- AEMPS CIMA: prescription status and leaflets of every aciclovir presentation in Spain
- MedlinePlus: Acyclovir (oral)
- MedlinePlus: Acyclovir topical
- NHS: Aciclovir
- NHS: Cold sores
- MSD Manual: Herpes simplex virus infections
Related guides
Medical Citations & Sources
This content is written and reviewed by a licensed physician with reference to the following official health authorities.
