Pernicious Anaemia Society
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Acyclovir - Anti-virals? B12 interaction?

Hi all,

I am investigating new routes along with B12.

I have been suggested Acyclovir 400mg 3x per day for 3 months in case it is a viral illness.

Does anyone know anything about this as I am concerened about taking prescription meds and worried it will interact badly with my B12?

This article I found interesting too - His symptoms are similar to mine combined with severe fatigue and brain fog:

many thanks

4 Replies

I don't know about the drug/b12 interactions, but I am interested in this story as I have recently had an unexpected improvement in some aspects of my health after taking L-lysine and vit c which Joe mentions as part of his regime - I've been looking for a reason why it has helped. (I took it for a cold sore on my lip). I've just had a B12 injection which continued the improvement. The improvement has mainly been with 'brain fog' and ear symptoms, tinnitus, screeching, 'fullness' of the ears, slight deafness, shooting ear pains, dizziness, muscle spasms in my neck, migraine and more. I still feel exhausted, but much more clear headed when I wake up for the last two days. I don't know if this is going to last though.


Hi Frodo,

I too am pretty intrigued by this. I am going to purchase some L-Lysine and Vit C and take them alongside the Acyclovir.

I have already been taking probiotics for the last few weeks, although at a much lower dose (about 3-5 million), and if things start to improve I may broach my doctor about the Flucanzole (anti-fungals) although I suspect she will be reluctant as she is with everything. A CFS 'specialist' recommended the Acyclovir which is the only reason she put me on them but we will see.

Let me know if you continue a similar approach and and I would be very interested to hear updates.

i will post on here too to let you know how things go.


I suppose you should perhaps check it is ok to take the Lysine with the Acyclovir as it has an anti viral action as well? I know Joe said he took both, but he is not medically qualified. FYI I get mine online from Victoria Health (just google them) who have a big supplement range, and I use Lamberts. They have a 'gentle' non acidic vitamin c available which is less likely to upset your stomach. The Lysine says 'free form easy absorption' on the front. I also take Bromelain which is a digestive enzyme and I believe has mild analgesic and anti inflammatory effects. is useful for checking what medicines/conditions these things should not be taken with and possible side effects. Just do a search in 'find a vitamin'.


Been taking acyclovir for years, never had a side effect. Still developed PA.


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