Cold sores and the sun: triggers and what helps

Health advice ·Published 10 October 2026 ·Reviewed 10 October 2026

Written by the Priceline Pharmacy Pacific Fair team. Reviewed by Jason Markey, BPharmSci, MPharm, Owner and Pharmacist.

General health information from a registered pharmacist. It doesn’t replace advice from your own pharmacist or doctor.

Yes, the sun can trigger cold sores. Health authorities list sun exposure, along with sunburn, wind, stress, illness and hormonal changes, among the things that can wake up the virus that causes them. Wearing a lip balm with SPF when you’re outdoors, and acting at the very first tingle, are two of the most useful things you can do.

Here are the questions we hear most often at the counter, answered in plain language. For lip protection, our beauty advisors can show you SPF lip balms in our skincare and sun care range, and our pharmacists can help when a cold sore is on its way.

What causes cold sores?

Cold sores are caused by the herpes simplex virus, most often type 1 (HSV-1). Healthdirect explains that once you’ve caught the virus, it stays in your body. It can lie quiet for long stretches, then reactivate and cause a cold sore, usually in the same spot.

Can the sun really trigger a cold sore?

Yes. The Better Health Channel (Victorian Government) lists exposure to sunlight as a trigger, and healthdirect includes skin damage from intense sun, cold or wind. The Australasian College of Dermatologists also names sunlight among the factors that make a recurrence more likely.

That’s why cold sores often turn up after a big beach weekend, a day at the theme parks or a windy afternoon on the Broadwater. In Queensland, Cancer Council Queensland says the UV Index reaches 3 or above every day, so lips need protection all year, not just in summer.

What are the other common triggers?

• feverish illnesses such as the flu or a chest infection;
• tiredness, and emotional or physical stress;
• hormonal changes, such as your period;
• windy conditions;
• sunburn.

Not every trigger can be avoided, but knowing yours helps you plan ahead.

Does lip balm with SPF help?

The Better Health Channel recommends wearing sunblock on your face and lips when you’re outdoors as a way to reduce cold sore outbreaks. A lip balm with SPF is an easy way to do this.

A few tips from our team:

• Apply it before you head outside, and reapply often, especially after eating, drinking or swimming.
• Keep one in your beach bag, car and handbag so you’re never caught out.
• Don’t share lip balm. The Australasian College of Dermatologists specifically advises against sharing lip balm, razors or towels.

The TGA notes that lip products with SPF are generally regulated as cosmetics, but they still have to meet the Australian sunscreen standard for testing and labelling. Pair your lip balm with a broad-brimmed hat, which shades your face as well.

What does the “first tingle” feel like, and why does it matter?

Most people feel itching, tingling or burning around the lip a day or two before the blister appears, according to the Better Health Channel. Small, painful, fluid-filled blisters usually follow, then they crust over and heal. Healthdirect says cold sores usually clear up completely within about two weeks.

That early tingle is your cue to act. Healthdirect notes that antiviral cold sore creams work best when you start them early, when you first notice tingling or a raised spot. Not everyone gets a warning sign, but if you do, don’t wait to see what happens.

What can I get from the pharmacy?

There are several options for cold sores at the pharmacy. They include antiviral creams, some of which are pharmacist-only, as well as cold sore patches and soothing products that may help ease discomfort and cover the sore. Which one suits you depends on how often you get cold sores, where the sore is, and your health and any other medicines you take.

Ask your pharmacist which suits you, and follow the label or your pharmacist’s advice. If you get cold sores often, it’s worth keeping a product at home so you can start at the first tingle. Healthdirect also suggests dabbing creams on gently rather than rubbing them in, and using ice to soothe pain.

Are cold sores contagious?

Yes. Cold sores spread through direct contact, such as kissing and skin-to-skin contact, and through shared items. Healthdirect notes you can pass on the virus even when there’s no visible blister, and the Better Health Channel says fluid from the blisters is the most infectious.

How can I avoid spreading a cold sore?

• Don’t kiss anyone while you have a cold sore, especially babies.
• Don’t share drink bottles, cutlery, towels, toothbrushes or lip products.
• Try not to touch, pick or lick the sore.
• Wash your hands after touching the area or applying a cream, and take care not to touch your eyes.
• Take extra care around newborns, pregnant people, older people and anyone with a weakened immune system.

Why are cold sores a concern around newborns?

NSW Health’s MotherSafe service warns that herpes can be a serious, life-threatening infection for a newborn baby. If you or a visitor has a cold sore, they recommend covering it, not kissing the baby, not touching the sore, and washing hands carefully before handling the baby. The Australasian College of Dermatologists advises urgent medical attention if you think a newborn has a herpes infection.

If you have a cold sore late in pregnancy or while caring for a new baby, speak with your pharmacist, GP or midwife about the safest way to manage it.

When to see a pharmacist or GP

Healthdirect advises seeing a doctor if:

• your symptoms are severe, such as a large, deep or very painful sore;
• you have a weakened immune system;
• there are signs the sore is infected, such as redness around it, pus or a fever;
• the sore isn’t healing, is spreading, or you have more than one;
• the sore has spread near your eyes;
• you get cold sores often.

Seek medical help urgently for:

• a painful red eye, or sores on or near the eye. The Better Health Channel warns that herpes in the eye can cause an ulcer that can damage sight, so early treatment matters;
• a newborn or young baby who may have been exposed to a cold sore, or who you think may have a herpes infection;
• a young child with painful mouth sores who isn’t drinking. The Better Health Channel notes a first infection can cause dehydration because swallowing hurts.

Call 000 in an emergency. If you’d like a same-day consultation while you’re at the centre, our in-store Help Medical GPs can see you.

This article is general information only and isn’t a substitute for personal advice from your doctor or pharmacist. Always read the label and follow the directions for use. If symptoms persist or you’re worried, talk to your pharmacist or GP. In an emergency, call 000.