1.11.09

Drugs, drugs, everywhere: Mouthwash edition

Holy crap, he's back!

Edit: And he's rusty! I totally messed up and confused menthol with methanol, a blatant error that has me absolutely teeming with embarrassment. Thankfully about a zillion (seven!) people commented on my mistake. I've patched things up for now, and I'll add a bit more later.

Yes, oh wonderful, patient, and most benevolent reader, I've decided to resuscitate this here blog. Life got kind of hectic about a year ago, so I decided to cool it with the hobby stuff (also neglected: Super Mario Galaxy, cooking with fresh produce, and inventing new cocktails based on Kool-Aid), and concentrate on getting my shit together. Things have remained hectic (read: I got lazy), but I miss blogging, so I'm going to aim for a reduced posting schedule with an emphasis on quality as opposed to quantity. I'm also planning on working my way through the archives and making some of my jargon-heavy posts more accessible.

Really, what better way to mark my return to the blogosphere (ugh, terrible word) than a comprehensive discussion of the pharmaceuticals that can be found in mouthwash, oh cleanser of souls (mouths) and provider for very poor alcoholics. Incidentally, for all you very poor alcoholics out there, forget mouthwash. The alcohol solution found in those hand disinfectant dispensers that keep popping up everywhere is basically 140-proof heaven.

Mouthwashes typically consist of water, ethanol, flavouring agents, sweeteners, humectants (to prevent your mouth from drying out), and active ingredients that do all the wonderful things that mouthwashes promise (prevent cavities! prevent tartar! prevent bad breath!).


I've decided to go with Listerine as my representative mouthwash, since they promised me a lifetime supply of Vanilla Mint in return for my plug (I wish!). From a what-drugs-does-it-contain perspective, Listerine offers three models for the consummate mouthwash user: Listerine, Advanced Listerine Plus/Listerine Tartar Control, and Listerine Total Care. I should add at this point that I'm talking about Canadian Listerine, which may differ from Listerine found in other countries. Listerine Listerine Listerine. Whew.

Your basic Listerine (this includes all of those fancy new flavours, which are for wusses who can't handle the original formulation) contains three active ingredients: eucalyptol, menthol, and thymol. All three have antiseptic properties, meaning that they are good at killing bacteria, including the ones that cause cavities and bad breath.

Eucalyptol, even though it has the -ol suffix associated with alcohols, is actually a cyclic ether (gasp!). As you may have already surmised, eucalyptol is found in shrubs and trees of the genus Eucalyptus, and is the predominant component of Eucalyptus oil. Eucalyptol apparently has a pleasant spicy taste (neat!), and for this reason it is added to cigarettes. It probably contributes to the taste of mouthwash as well.

Menthol, not to be confused with methanol (a bad-ass alcohol can get you drunk but also render you blind and possibly dead), was covered in a previous post of mine.

Thymol is found in plants of the genus Thymus, including common thyme, which used as a cooking herb. Thymol has seen use as a means of killing varroa mites in bee colonies, killing moulds growing on books, and killing dermaophytous fungi (the ones that cause ringworm). Thymol apparently can activate GABA receptors, meaning that it can act like Valium at certain doses. Interestingly, the structure of thymol is similar to propofol, a commonly used general anaesthetic that was what killed Michael Jackson.

Advanced Listerine Plus and Listerine Tartar Control (they are essentially the same thing, so buy whatever is cheaper!) both contain zinc chloride in addition to the stuff found in basic Listerine. Zinc chloride is used in lots of fascinating organic synthesis reactions that I'm not going to talk about. It also is apparently good at inhibiting the development of supragingival dental calculus, which is a nice way of saying it prevents that white goopy stuff that the dental hygienist scrapes off of your teeth from forming in the first place. This may have something to do with it being corrosive (it is used in industry to clean metal surfaces by dissolving metal oxide coatings).

Finally, we have Listerine Total Care, which is a nice shade of purple and includes everything mentioned so far plus sodium fluoride, which is a mind control agent that the government has added to our water to keep us placated. WAKE UP SHEEPLE!

- http://en.wikipedia.org/wiki/Eucalyptol
- Apidologie_0044-8435_1991_22_2_ART0006.pdf
- http://jada.ada.org/cgi/content/full/132/1/94

12 chemically inspired comments:

Anonymous said...

I think you confused methanol with menthol. Both alcohols, but otherwise completely different.

Epicanis ( http://www.bigroom.org/wordpress ) said...

For shame - leave us hanging for so long, only to mix up Menthol (a phenolic compound like the others) and Methanol in your return post...

Welcome back nonetheless, though - good to see some interesting activity popping up here again!

Andre said...

Um dude. Dude.

Menthol does NOT equal methanol. Tons of non-chemists make this mistake all the time.

Menthol is an optically active alcohol derived from all sorts of mint oils. It's really cool (pun kind of intended, since it
s what gives that cooling sensation in your mouth) and totally not harmful.

Check out the wiki page on it for more info.

http://en.wikipedia.org/wiki/Menthol

Anonymous said...

Menthol not methanol,

Anonymous said...

Welcome back. Perhaps you're a little rusty? Menthol is a mint oil, not wood alcohol. As Menthol's Wikipedia says "Not to be confused with Methanol"

Anonymous said...

Chris, I'm sorry but you totally messed up this post. Methanol (CH3OH), the poisonous alcohol you described, is completely different than menthol, the terpene responsible for the minty taste of peppermint oil, and which acts by triggering the cold receptor.

Ron said...

Menthol =/= Methanol

Chris said...

ARGH! Total toxicology fail on my part.

Thank you for correcting me, everyone. Apparently I need to sit down with my good friends Casarett and Doull for a little bit to get back on track.

Chiral Jones said...

I'll let you slide on the methanol slip because I liked the fluoride quip.

Welcome back.

Beyonce said...
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The Curious Chemistry Grad said...

Love your site.. just started to stumble upon all other chemists blogs!

Keep it up!