Aciclovir vs Alternatives: Which Cold Sore and Herpes Treatment Works Best?

When you get a cold sore or a herpes outbreak, time matters. The sooner you treat it, the less pain you feel and the faster it heals. Aciclovir has been the go-to treatment for decades - cheap, effective, and widely available. But is it still the best choice today? With newer options on the shelf, many people are asking: should I stick with aciclovir, or is there something better?

What Aciclovir Actually Does

Aciclovir is an antiviral drug that stops the herpes simplex virus from multiplying. It was first approved in the 1980s and remains one of the most studied antivirals in the world. It works by mimicking a building block the virus needs to copy its DNA. When the virus tries to use aciclovir instead of the real building block, its replication process breaks down.

Aciclovir is available as a cream, tablet, or intravenous injection. For most people with cold sores or mild genital herpes, the oral tablet (200 mg taken five times a day for five days) is standard. The cream helps if applied at the very first sign - a tingling or itching feeling before the blister appears.

Studies show aciclovir can shorten outbreaks by about one day and reduce pain and blistering. It’s not a cure - the virus stays in your nerves forever - but it keeps flare-ups under control. It’s also safe for most people, including pregnant women and children.

Why People Look for Alternatives

Even though aciclovir works, it’s not perfect. Taking five doses a day is a hassle. Missing a dose can reduce its effectiveness. And for some, it just doesn’t work fast enough.

That’s where newer antivirals come in. They were designed to be easier to use and more potent. The two main alternatives are valacyclovir and famciclovir. Both are prodrugs - meaning they turn into aciclovir (in the case of valacyclovir) or a similar compound (famciclovir becomes penciclovir) after your body absorbs them.

The big advantage? Fewer pills. Once or twice a day instead of five times. That makes a huge difference in real life. People are more likely to finish their full course when the dosing is simpler.

Valacyclovir: The Most Popular Switch

Valacyclovir is the hydrochloride salt of aciclovir, converted into aciclovir after absorption. It’s sold under brand names like Valtrex and is now available as a generic.

For cold sores, you take 2,000 mg twice a day for one day - that’s it. For genital herpes, it’s 1,000 mg once or twice daily for five days. Clinical trials show it works just as well as aciclovir, but with fewer doses and faster symptom relief.

A 2023 review in the Journal of Antimicrobial Chemotherapy found valacyclovir reduced healing time by 1.5 days compared to placebo, and by 0.7 days faster than standard aciclovir. It also lowers the chance of spreading the virus to partners.

The downside? Price. Even as a generic, valacyclovir costs about 30% more than aciclovir in Australia. But if you’re someone who forgets pills or hates taking medication five times a day, the extra cost might be worth it.

Famciclovir: The Fast-Acting Option

Famciclovir is a prodrug that converts into penciclovir, a compound similar to aciclovir but with a longer half-life in cells. It’s sold as Famvir and is also available generically.

For cold sores, you take 1,500 mg as a single dose. For first-time genital herpes, it’s 250 mg three times a day for five days. The single-dose option for cold sores is unique - no other antiviral offers this.

Studies show famciclovir works as well as valacyclovir and aciclovir, but with slightly faster pain relief. One trial found people using famciclovir reported less pain within 24 hours compared to those on aciclovir.

It’s not as widely used as valacyclovir in Australia, partly because it’s not always stocked in local pharmacies. But if you’ve tried aciclovir and still get lingering symptoms, famciclovir is worth asking your doctor about.

Topical Creams: Do They Help?

Many people reach for aciclovir cream or penciclovir cream (Denavir) at the first sign of a tingle. But here’s the truth: topical treatments only help a little.

Aciclovir cream reduces healing time by about half a day if used within the first 24 hours. Penciclovir cream is slightly more effective, cutting healing time by 0.8 days. But neither compares to oral medication.

Topical creams are best for people who can’t take pills - young children, people with swallowing issues, or those who only get occasional outbreaks. For frequent or severe outbreaks, oral antivirals are far superior.

What About Natural Remedies?

You’ll see ads for lysine supplements, tea tree oil, lemon balm, or zinc oxide creams claiming to treat herpes. Some have small studies backing them, but none match the evidence for aciclovir or its alternatives.

Lysine, for example, has been studied since the 1980s. A 2020 meta-analysis in BMJ Supportive & Palliative Care found no significant difference between lysine and placebo in reducing outbreak frequency or severity. Tea tree oil can irritate skin and isn’t regulated. Zinc oxide may help dry out blisters, but it doesn’t stop the virus.

Don’t waste money on supplements that promise miracles. Stick with what science proves works.

Which One Should You Choose?

Here’s how to pick:

• Choose aciclovir if you want the cheapest option, have mild outbreaks, and can remember to take five doses a day.
• Choose valacyclovir if you want the best balance of effectiveness, convenience, and availability. It’s the most common switch from aciclovir.
• Choose famciclovir if you want the fastest pain relief or the single-dose option for cold sores. It’s less common but just as effective.

For people with frequent outbreaks (more than six a year), doctors often recommend daily suppressive therapy. Valacyclovir (500 mg once daily) is the most studied for this. It reduces outbreaks by 70-80% and cuts transmission risk to partners by up to 90%.

Side Effects and Safety

All three drugs are very safe. The most common side effects are mild: headache, nausea, or dizziness. These happen in less than 10% of users.

Severe reactions - like kidney problems or allergic rashes - are rare. People with kidney disease need lower doses. Always tell your doctor if you have kidney issues before starting any of these.

None of these drugs interact badly with alcohol, birth control, or common painkillers. They’re safe during pregnancy and breastfeeding, though you should always check with your doctor first.

Where to Get Them in Australia

All three drugs are on the Pharmaceutical Benefits Scheme (PBS). That means you pay the subsidized price - around $7-$10 for a course of aciclovir, $15-$25 for valacyclovir or famciclovir, depending on your concession status.

You need a prescription for tablets. Creams are available over the counter at pharmacies, but they’re not as effective. If you get outbreaks regularly, talk to your GP about getting a repeat prescription. Many doctors will give you a script for 3-6 months’ supply.

What If It Doesn’t Work?

Most people respond well. But if your outbreak doesn’t improve after 7-10 days, or if you get more than 10 outbreaks a year, you might have a resistant strain. That’s rare - less than 1% of cases - but it happens.

In those cases, doctors may switch to foscarnet or cidofovir, which are stronger but used only in hospitals. For most people, though, switching from aciclovir to valacyclovir or famciclovir is enough.

Also, stress, illness, sun exposure, and hormonal changes can trigger outbreaks. Even with the best medication, managing triggers helps. Use sunscreen on your lips. Get enough sleep. Reduce stress. These won’t cure herpes, but they’ll help you get fewer outbreaks.

If you’ve had more than two outbreaks in the last year, talk to your doctor about daily treatment. It’s not just about comfort - it’s about protecting your partners and reducing long-term nerve damage from repeated flare-ups. The right antiviral, taken the right way, can change your life.