NAC and Rotten Eggs – Where to draw the line?

One effective intervention in autism, particularly to reduce stereotypy, is N-acetylcysteine (NAC).  Here NAC is being used as an anti-oxidant in its own right and as a precursor to the body’s own main anti-oxidant, called GSH.  Classic autism is associated with oxidative stress and so NAC should be beneficial.

In much of Europe, NAC is seen primarily as a pharmaceutical, in North America, and much of the rest of the world, NAC is primarily just another supplement.

As a drug, it is mainly used as a so-called mucolytic agent, and as such is used as a cough medicine, because it breaks down mucus and liquefies it, making it easier to cough up.  It is frequently prescribed by doctors for children, but only in some parts of the world.

The problem with NAC, and all supplements, is quality control.  There is pressure to drive down prices and so quality will vary.  NAC is not particularly stable (it is labile) and so it tends to break down and release some foul smelling compounds.

For those who remember chemistry from school, the chemical formula is C₅H₉NO₃S and the following chemical structure:

The smell of rotten eggs is associated with H₂S, hydrogen sulphide/sulfide.  The ‘S’ in NAC is sulphur/sulfur and so when it breaks down or oxidizes you get a nasty smell.

The question is how much of a smell is normal and how much means your cheap NAC capsule has spoiled to the point of being worthless?

There is plenty of online discussion on this subject among regular users of NAC.  As usual, much is nonsense; some people are even saying that NAC has to stink and that it is a sign that it is good.

When it is freshly produced, there should be very little smell.  When you open the pharmaceutical NAC from its blister pack there is no smell whatsoever.

Cheap NAC

Since you need large amounts of NAC for treating autism, I found a brand of the cheap NAC capsules, but I always open the individual capsules and mix them in juice.  I never had any stinky bad egg smell until recently.  Now as soon as I open the jar, let alone the capsule, there is a potent smell.  Try a jar from a different batch, same smell.  More to the point, I have noticed small signs of stereotypy when Monty, aged 10 with ASD, goes for a swim.  He is swimming in the water and then starts wiggling his fingers and looking at them.

So I have decided to switch to the pharmaceutical NAC, which where we live is called Fluimucil and is made in Switzerland.  You buy it in the pharmacy over the counter, but without a prescription.  The cheap NAC does not say where it is made, or even have a use by date.  I suspect that different batches are made by totally different producers, whichever offers the lowest price.

The well-known expensive brand of NAC sold in the US is actually produced in Europe, if it turns out to be Swiss, we can probably guess who is making it for them.

It is clear that when the cheap NAC is very fresh, it works fine, but I want a product that functions as it should, 100% of the time.

I will see if the small re-emerging signs of stereotypy disappear with the Swiss NAC.