When does a cold sore STOP being contagious?

Hi there,

Here’s a good question I came across:

“Am I still contagious? It’s just been a red spot slowly fading after the scab fell off about 4 days ago.”

You know how unpleasant an outbreak can be.

So the last thing you want to do is spread your outbreak to another area on your lips (or face).

Because if you do, you’re looking at another few weeks of pain and suffering.

Even worse, you could pass on the virus to a loved one if you’re not careful.

Kiss your spouse or kids just a little too quickly can mean gifting them the virus that keeps on giving…

So it’s perfectly valid to wonder at what point can you move on and stop worrying about it.

To answer this question, you have to think about your cold sore in terms of viral load.

What’s the viral load you ask?

It’s the amount of viral particles (think total number of copies of the herpes virus) in your body at any given time.

Generally speaking, the higher the viral load, the bigger the cold sore.

Now, the viral load doesn’t stay the same throughout an outbreak. It goes a little something like this:

  • It starts low at first, and increases gradually during the initial tingling/redness stage
  • Then, it keeps increasing until it peaks during the blister stage
  • Finally, it gradually lowers from there as your immune system eliminates the viral particles and the sore scabs over

It’s basically follows a typical bell curve.

So the question is, at what point during this process is the viral load low enough that the risk of transmission becomes nil?

Well obviously, the longer you can wait, the better. If you can hold off smooching other people until you skin fully heals, that’s great. But that can take weeks.

Instead, a good rule of thumb is that if the scab has fallen off, the risk of contagion is low enough to not worry about it.

Smooch away.


You need to understand that all this is risk management only.

The probability of you passing on the virus to someone else is NEVER zero, as long as the virus lives inside you.

The truth is the higher the viral load, the higher the risk of passing on the virus. And the lower the viral load, the lower the risk of burdening someone else with this disease.

Yes, even when you DON’T have a cold sore at all, there is still a possibility that you are contagious. It’s called asymptomatic shedding.

But don’t worry about that. You’re more likely to get struck by lightning while winning the lottery than having that happening. It’s damn near impossible. Heck, you’re infinitely more likely to die in a car accident.

What you really want to worry about are the times when you’re dealing with a high viral load, i.e. during most stages of an outbreak.

ESPECIALLY during the oozing blister stage.

That’s the worst. In every way possible, including in terms of spreading/contagion.

But if you’re past the scabbing stage, the risk of contagion is extremely low, even if the skin is still a little pink where the scab was. That’s just a sign your skin is still repairing itself, not that it’s still infected.

But of course, NOT having a cold sore is the best way to keep your odds of transmitting the virus to someone else to a minimum.

And the best way to do that is to focus on preventing outbreaks from ever happening in the first place by blocking the reactivation of the herpes virus.

If you want to learn how to do that, take the Cold Sore Quiz I put together at the link below:

Take the 60-Second Cold Sore Quiz Right Now

It drills down and finds the root cause of YOUR cold sores, and gives you a personalized strategy to stop the herpes virus from reactivating and cold sores from breaking out in the first place.

Discover how to *block cold sores at the very source, without antivirals or strict diet rules. Sign up to read daily email tips and download the first chapter of the “Cold Sore Control” outbreak prevention system for free right now…
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Chris "the Cold Sore Killer" Mueller