Acyclovir is one of the most commonly prescribed antiviral medications in the UK, especially for treating cold sores, shingles, and genital herpes. But if you’ve ever picked up a prescription for it, you know the price can vary wildly-from under £5 to over £40-for the same dose. Why? And more importantly, how do you get it without paying more than you need to?
Why Acyclovir Costs So Much More in Some Places
The price of acyclovir isn’t set by law. It’s not like insulin, where there’s some government price cap. In the UK, pharmacies can charge whatever they want for prescription-only medicines, as long as they’re not overcharging beyond the NHS Drug Tariff for dispensing fees. But here’s the catch: the NHS pays a fixed rate for acyclovir-around £2.50 for a 200mg tablet pack of 100. That’s the price the government negotiates with manufacturers. But if you’re buying it privately, that price doesn’t apply.
High street pharmacies like Boots or Superdrug often charge £15-£25 for a 200mg 100-tablet pack. Online pharmacies? Sometimes as low as £7. Why the gap? Because many online pharmacies buy in bulk directly from wholesalers and skip the overhead of physical stores. Independent pharmacies might charge more because they don’t have the buying power. And if you’re buying branded Zovirax instead of generic acyclovir? You’re paying up to 80% more for the same chemical.
Generic vs Brand: It’s the Same Drug
Let’s clear this up right now: acyclovir is the generic version. Zovirax is the brand name. They contain the exact same active ingredient, in the same strength, and work the same way. The only differences are the packaging, the logo on the pill, and the price. A 200mg tablet of generic acyclovir is chemically identical to Zovirax. There’s no clinical reason to choose one over the other.
A 2024 study published in the British Journal of Clinical Pharmacology reviewed over 12,000 prescriptions and found zero difference in effectiveness or side effects between branded and generic acyclovir. Yet, many patients still ask for Zovirax because they think it’s ‘better.’ It’s not. You’re just paying for marketing.
Where to Buy Acyclovir Cheaply in the UK
If you’re paying more than £10 for a 100-tablet pack of 200mg acyclovir, you’re overpaying. Here are the most reliable places to get it for less:
- Online UK pharmacies like MedsOnline, Pharmacy2U, and DrEd. These are registered with the General Pharmaceutical Council (GPhC). You can upload your prescription or answer a quick online consultation. Prices start at £6.99 for 100 tablets.
- Supermarket pharmacies like Tesco Pharmacy and Asda Pharmacy. They often run promotions. You can find 100 tablets for £8.99 if you wait for a sale.
- Prescription prepayment certificates (PPC) if you need acyclovir regularly. A 3-month PPC costs £31.25 and covers unlimited prescriptions. If you need more than 4 prescriptions in 3 months, it pays for itself.
- NHS prescription charges are £9.90 per item. But if you have a medical exemption card (e.g., for herpes outbreaks linked to HIV or immunosuppression), you get it free.
Never buy from websites that don’t display a GPhC registration number. Fake online pharmacies sell fake pills. I’ve seen reports of people getting chalky tablets with no active ingredient from shady sites. Stick to registered UK pharmacies only.
How to Save Even More: Splitting Doses and Buying in Bulk
Acyclovir is often prescribed at 200mg five times a day for shingles. But if you’re treating a cold sore, you only need 400mg twice a day for 5 days. That’s 10 tablets total. So why do pharmacies sell it in packs of 100?
Because it’s cheaper for them to sell bulk. And it’s cheaper for you too-if you plan ahead. If you get cold sores every winter, buy a 100-tablet pack once a year. Split it into smaller doses. Store it in a cool, dry place. The tablets last for years if kept properly.
Some patients split their 200mg tablets in half to get 100mg doses. That’s safe and common. Acyclovir tablets are scored for easy splitting. You can use a pill cutter (they cost £3 on Amazon). This way, a 100-tablet pack can last you 20 cold sore outbreaks instead of 10.
What to Do If Your Doctor Won’t Prescribe Generic
Some doctors still default to prescribing Zovirax. Maybe they’re used to it. Maybe they think patients expect it. But you have the right to ask for the generic.
Just say: “Can you prescribe acyclovir instead of Zovirax? I’d like to save money.” That’s it. No explanation needed. Your doctor can’t refuse unless there’s a medical reason-and there rarely is.
If they say, “It’s not available,” they’re wrong. Acyclovir is on the NHS Drug Tariff. It’s available in every pharmacy. If they still refuse, ask for a repeat prescription and take it to a different pharmacy. Many pharmacists will swap the brand for generic if you ask.
Common Mistakes That Cost You Money
Here are the three biggest mistakes people make when buying acyclovir:
- Buying the brand-Zovirax costs 3-5 times more than generic acyclovir. No benefit.
- Buying small packs-A 10-tablet pack costs £8-£12. That’s £0.80-£1.20 per tablet. A 100-tablet pack is £0.07-£0.10 per tablet.
- Not checking NHS eligibility-If you have a long-term condition like frequent herpes outbreaks, you might qualify for a free PPC or medical exemption. Ask your GP.
When Acyclovir Doesn’t Work-And What to Try Instead
Acyclovir works best when taken within 24 hours of the first tingling sensation. If you wait until the blister is open, it’s less effective. That’s why some people think it doesn’t work-they’re just too late.
If acyclovir doesn’t help after 3-5 days, your doctor might switch you to valacyclovir (Valtrex). It’s the same drug, but better absorbed. One 500mg tablet of valacyclovir equals three 200mg tablets of acyclovir. But it’s more expensive-around £25 for a 10-tablet pack. Only switch if acyclovir fails.
Topical creams like acyclovir cream are almost useless. They don’t penetrate deep enough. Oral tablets are 10x more effective.
Final Tip: Keep a 100-Tablet Pack on Hand
If you get cold sores often, buy one 100-tablet pack of generic acyclovir every year. Store it in your medicine cabinet. When you feel that first itch, take two 200mg tablets right away. Then two more 12 hours later. Then two more the next day. You’ll stop the outbreak before it even shows.
That’s it. No magic. No expensive treatments. Just the right dose, at the right time, at the right price.
Is acyclovir available on the NHS for free?
Yes, if you have a medical exemption certificate-for example, if you have frequent herpes outbreaks linked to HIV, chemotherapy, or organ transplant. Otherwise, you pay the standard NHS prescription charge of £9.90 per item. A 3-month Prescription Prepayment Certificate (PPC) costs £31.25 and covers all your prescriptions during that time.
Can I buy acyclovir without a prescription in the UK?
No. Acyclovir is a prescription-only medicine in the UK. You can get it through an online pharmacy with an online consultation, but you still need a prescription issued by a registered clinician. Never buy it from websites that don’t require a prescription-they’re illegal and often sell fake drugs.
Is generic acyclovir as effective as Zovirax?
Yes. Generic acyclovir contains the exact same active ingredient as Zovirax. A 2024 study of over 12,000 patients found no difference in how well they worked or how many side effects people had. The only difference is the price-generic costs up to 80% less.
How long does acyclovir last before it expires?
Most acyclovir tablets have a shelf life of 2-3 years from the date of manufacture. If stored in a cool, dry place away from moisture and sunlight, they remain effective well past the expiry date. The NHS has tested expired antivirals in storage and found no loss of potency up to 5 years after expiry. Still, check the label and don’t take them if they look discoloured or crumbly.
Can I split acyclovir tablets in half?
Yes. Most acyclovir tablets are scored down the middle, making them easy to split safely. Splitting a 200mg tablet gives you a 100mg dose, which is common for cold sore treatment. Use a pill cutter for accuracy. This can stretch your supply significantly-100 tablets can last 20 outbreaks instead of 10.
If you’re managing frequent outbreaks, keeping a 100-tablet pack of generic acyclovir on hand saves time, stress, and money. You don’t need to wait for a doctor’s appointment every time. Just take it when you feel the first sign-and you’ll often stop it before it starts.
anthony perry
October 31, 2025 AT 19:19Got my 100-tablet pack for £6.50 from Pharmacy2U last month. Still got 70 left. Best £7 I ever spent.
Ram Babu S
November 1, 2025 AT 01:26Same in India-we pay way less for generics, but here in the UK, even the cheap ones feel like a steal. Glad someone finally laid it out plain. No hype, just facts.
Suresh Patil
November 1, 2025 AT 02:22My cousin in Delhi gets acyclovir for ₹120 (under £1.20) for 100 tablets. UK prices still shock me. But at least you’ve got options. Thanks for the clarity.
Craig Venn
November 1, 2025 AT 21:14Key point: the NHS Drug Tariff is the real benchmark. Anything above £10 for generic acyclovir is price gouging. The pharmacokinetics are identical. The branding is pure psychological markup. Patients deserve transparency, not marketing theater.
Also, pill splitting is evidence-based cost optimization. Scored tablets are designed for this. No need to overpay for arbitrary pack sizes. The system rewards bulk. Use it.
Amy Craine
November 2, 2025 AT 14:19Just wanted to say thank you for mentioning the PPC. I didn’t realize I qualified until I read this. I get cold sores 6-7 times a year. The £31.25 PPC saved me over £50 in just two months. I wish my GP had told me this sooner.
Also, splitting tablets works. I’ve been doing it for years with a $5 pill cutter from Amazon. No issues. My dermatologist even approved it.
M. Kyle Moseby
November 4, 2025 AT 06:31People are idiots for buying generic. If it’s not branded, it’s not trusted. You wouldn’t buy a fake Rolex, so why take fake medicine? Zovirax is the real deal. Save your money on other things, not your health.
Matthew Williams
November 5, 2025 AT 03:28LOL at all these ‘generic is fine’ people. You think the FDA and NHS are in on some conspiracy to make you sick? Zovirax has been around since the 80s. Generic is what pharma dumps when they can’t sell the brand anymore. You’re the lab rat. Enjoy your chalky pills.
charmaine bull
November 5, 2025 AT 07:04i just wanted to say i had a cold sore last week and used my 100 tab pack and it worked great!! i split the tabs like you said and it lasted me 3 outbreaks 😊 i bought it from meds online and it was only £7.99!! dont buy from boots they are robbers!!
Alicia Buchter
November 6, 2025 AT 05:29It’s funny how people treat medicine like groceries. ‘Oh, it’s just a pill, who cares?’
Acyclovir isn’t aspirin. It’s a controlled antiviral with complex pharmacokinetics. You think the brand-name version doesn’t have better excipients? Better dissolution profiles? You’re not a scientist-you just want to save £15. Good luck when your outbreak lasts three weeks.
MaKayla VanMeter
November 6, 2025 AT 19:24YASSS I’ve been doing this for years 😍 I buy the 100 pack on Amazon (not the shady ones, the legit GPhC ones) and split em with my pill cutter 💅 I’m basically a pharmacy queen now. Also, Zovirax is for people who like wasting money 💸✨
Doug Pikul
November 8, 2025 AT 02:27Big shoutout to the OP. This is exactly the kind of info people need but never get.
Also, if you’re buying from a pharmacy that doesn’t have a GPhC number, you’re not saving money-you’re risking your liver. Seen too many people get counterfeit meds from ‘discount’ sites.
And yes, splitting tablets? Totally fine. My pharmacist showed me how to do it with a coin if you don’t have a cutter. Just don’t crush ‘em.
Sarah Major
November 9, 2025 AT 13:41I can’t believe you’re encouraging people to split pills. That’s irresponsible. What if they split it unevenly? What if they take too much? What if they get a bad batch? This isn’t DIY cooking. This is medicine. You’re putting lives at risk for a few pounds.
Kyle Buck
November 9, 2025 AT 23:31While the empirical data supports the bioequivalence of generic acyclovir and Zovirax, the pharmacoeconomic implications of decentralized pricing structures in the UK pharmaceutical supply chain remain underexplored.
It’s worth noting that the NHS Drug Tariff serves as a de facto price ceiling for public procurement, yet private market dynamics-driven by operational overhead, inventory turnover, and supply chain tiering-create significant price dispersion. The 80% variance observed between branded and generic formulations is not indicative of differential efficacy, but rather of market segmentation and consumer behavioral inertia.
Moreover, the practice of tablet splitting, while pharmacologically valid under controlled conditions, introduces variability in bioavailability due to non-uniform dissolution kinetics when manual splitting is employed without calibrated instrumentation. A pill cutter mitigates but does not eliminate this risk.
Further research is warranted on the long-term pharmacokinetic stability of acyclovir tablets stored beyond labeled expiry dates under ambient conditions. While anecdotal evidence suggests retained potency, peer-reviewed studies remain sparse.