I would think this would be fine, i know cold n flu tablets you cant take however i would double check with your doctor first.

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Why breastfeed? Does it have no affect at all on a child? No one knows…
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I would check the package of the Cold and Flu relief. Usually, if it is not good for pregnant or breastfeeding women, then it will have a written warning.

You can also ring up your local chemist. Get their number from the phonebook and just tell them the product name, and they will be able to tell you.
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check with the pharmacy or with your maternal health line, I recently had a cold and I was told its best just to take nothing, maybe just some panadol, better to be safe than sorry
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You should check with the pharmasist.
Kellymom.com has some other suggestions that are compatible with breastfeeding.
http://www.kellymom.com/health/meds/cold-remedy.html
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http://www.kellymom.com/health/meds/cold-remedy.html

You'll have to check the ingredients individually, but this is a very reliable site:

"Cold and Allergy Remedies Compatible with Breastfeeding"

http://www.kellymom.com/health/meds/cold-remedy.html

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