Is colloidal silver safe for pregnancy & breastfeeding?
The short answer:
We don’t know. I wouldn’t take it while pregnant or breastfeeding, and I don’t recommend it to my clients either.
The long answer:
What is colloidal silver?
Colloidal silver is a preparation containing very small particles of silver suspended in a colloidal base. A colloid just means that you have molecules or particles of one substance suspended in another substance in such a way that they disperse evenly & won’t come out of solution or settle to the bottom of the mixture. Some people use a very dilute form of colloidal silver as an antimicrobial; it is used both topically and internally as a supplement.
Does it work as an antimicrobial?
Probably – in some situations, although there are no solid clinical trials that support its use. Silver-based preparations were widely used by medical professionals before the advent of antibiotic drugs. According to the Natural Medicines Database (subscription required), colloidal silver is likely useful as an antimicrobial. Most of the studies around this use are looking at topical preparations, not internal/oral use.
What’s the concern?
Colloidal silver is not a benign, perfectly safe supplement. It’s a metal. With no known role in the human body. It does not normally appear in food and there is no compelling reason to ingest it. To me, that means that the burden of proof for its safety & efficacy is much higher than for a food product or herbal medicine.
When I say that something is probably safe, there are two kinds of “probably.”
The first kind of “probably” has to do with things that are common in the human diet, like celery and chamomile tea. Do we have clinical studies, RCTs proving that they are safe to consume during pregnancy and lactation in reasonable amounts? No. Does good common sense, the information we do have about their safety, constituents, mechanisms of actions, and a long history of human consumption indicate that both are likely safe? Yes. I am comfortable recommending both chamomile tea and celery to pregnant and lactating mothers for this reason.
The second kind of “probably” relates to substances that we do not normally ingest as humans. Things that we are taking specifically for therapeutic benefit and that serve no other purpose in our diets or lives. This includes substances like heavy metals and pharmaceutical drugs.
Is there a time & a place for them? Absolutely, yes. We need medications sometimes. And we also need to make darn sure that they are safe and effective to balance the risks and the benefits. This is why there is a relatively rigorous process to bring a pharmaceutical to the market (and yes, I am fully aware of just how flawed this process is). Many of these substances are probably safe, but should be proven safe and effective before we recommend them for pregnant and lactating women. See the difference?
Colloidal silver is “probably” safe to ingest in very low doses over short periods of time according to my second definition above. As it stands, we don’t have a lot of evidence that it is unsafe in low doses, but we also don’t have very much solid evidence that it works (testimonials on the internet aside).
Almost all of the studies that have been done involve topical use (for example the use of silver in dressings to cover wounds or in catheters to prevent microbial infection).
What are the potential risks?
There are a few troubling animal studies of embryonic changes associated with colloidal silver use (for example, see here, here and here). Are these directly applicable to humans? No, not necessarily. But they are a potential red flag worth considering in the absence of any other available data. People who take very high doses (beyond what you would normally ingest with most supplements) actually turn a bluish-grey color, permanently (!). To me, this is another hint that perhaps it’s not entirely safe.
Is it worth the risk?
Nope. Not in my opinion.
In pregnancy and lactation, we need to have an even higher standard for determining safety. If I’m pregnant or breastfeeding, there’s no way I’m knowingly ingesting a heavy metal that has not been proven safe for me and my baby. Unfortunately, colloidal silver just doesn’t have the data to support its use in these circumstances. It hasn’t been systematically tested in this population (or any population, really). We don’t know how – if at all – it affects the baby in utero or while nursing.
Is there a chance that it’s safe? Yep. Could be. But there’s also a chance that it’s not. We just don’t know. And to me, it’s not worth it to take that risk, especially when a little one is involved.
Herbs in Pregnancy and Lactation: Cheat Sheet
This concise summary lists all herbs to pick from when working with clients who are pregnant or lactating. It's one of my most-useful clinical tools!