I had been told exactly the same thing by the chemist, but my OB told me I could use Zovirax!!! That was when I was PG with Jacob and I did use it and he's fine. The concern is with the active ingredient, which is acyclovir (sp?) however as I said, my OB told me I could use it and I did LOL.

I got a cold sore early on in this PG and couldn't be bothered going into it with the chemist so I bought a Betadine one (equally as safe as the Nyal one) and I have to say, it worked REALLY well......