I originally posted this about coumarin in 2020.
Even if a blend has a very heavy usage of 5% of deer tongue you’d have to smoke at least 16 bowls a day to begin tickling the bottom of the NOAEL (No Observed Adverse Effects Limit) in The European FDA’s study. This study also used a factor of 10 to account for the rare individuals who might metabolize coumarin differently.
The ban on deer tongue was a big over reaction to a problem that didn’t exist.
Here’s the full text for your review. As always, do what you think makes sense for you.
Deer Tongue Usage
Over the past year I have become a big fan of adding Deer's Tongue (DT) to a few of my pipe blends. I am getting quite tired of reading about how dangerous it is so I thought I'd set the record straight. For most of this little article I will refer to DT and Tonka Beans (TB) collectively as Coumarin since this is the active ingredient in the two.
Deer Tongue is an herb that grows mainly in the South East of the U.S. It had been used historically to add a Vanilla flavor to things like ice cream and tobacco. The FDA in its infinite wisdom banned its use in the '50's due to rats studies showing that the active ingredient in DT was Coumarin and was toxic to the liver. Adding to the "scare" of how dangerous it was a researcher came along and figured out a way to make an anti coagulant out of it. He called it Coumadin and trademarked it as the prescription drug Warfarin. Even though banned, the tobacco industry supposedly was still using it through the '70's!
The truth is, Coumarin has absolutely no blood thinning effects whatsoever. The studies in rats showing liver toxicity are irrelevant to humans since we metabolize Coumarin via a different pathway than rats. The European version (EFSA) of the FDA has reviewed this issue several times over the years and has concluded that the No Observed Adverse Effects Limit (NOAEL) is 10mg/kg. Since there is a small fraction of humans that metabolize Coumarin differently the EFSA used a safety factor of 10 to state that Coumarin is safe to take at 1mg/kg of body weight. The German version of the FDA has said that 25mg/kg is the lowest dose that would cause liver damage in humans.
So.. Both DT and TB contain about 3% by weight of Coumarin. This is the amount of "free" coumarin available. They also contain bound coumarin but this cannot be absorbed.
What this means: If you were to make a pipe blend containing 5% DT (5% is on the high side for using as a flavor constituent) you would get about 4.5mg of coumarin per bowl, based on a bowl containing about 3g of tobacco. So, if you weighed about 160lbs (73kg) you would have to smoke about 16 bowls everyday to get to the NOAEL! I should note that the NOAEL is standard measurement used to show product safety. It is much more "safe" to use than the LD50 measurement. NOAEL means there is NO EFFECT AT ALL at that limit!
USAGE: I like to use DT at 5% of my blend. That % is a little on the high side but I like it. If you use DT I'd suggest starting out at 2% and work your way up till you find something you like. DT is available in either powder or cut. I would not recommend the powder because it would not mix with shredded leaf. On the other hand, if you are using it for Snus/Dip, the powder would be the preferred form. Penn Herb sells the cut and powdered version of DT and 4Noggins sells the powdered version.
Tonka Beans weigh on average 1.25g per bean. They are usually ground to a powder and then added to alcohol to extract the flavor. The alcohol mixture is then sprayed onto the tobacco. I have used water and alcohol, separately and have not noticed a difference in the taste. Personally, I do not care for tonka beans because I get a much better (more exact) dose of Coumarin when I use DT. I do not have to grind it up and dilute it with alcohol. I just add it to my shredded tobacco. Tonka Beans are readily available on Ebay.
Additionally, Coumarin is supposed to be the most used ingredient in the cosmetics industry for perfumes and lotions. It is absorbed by the skin. This is why the EFSA has periodically reviewed it. Also, Cinnamon contains 4% by weight of Coumarin yet I do not see the FDA banning cinnamon! There are 2 types of Cinnamon, Cassia is the one that contains 4% Coumarin and it is the one consumed by close to 99% of the people worldwide. Ceylon cinnamon is the "true" cinnamon and it contains negligible amounts of coumarin.
Keep in mind too that pre diabetics and diabetics are taking at least 2g per day of Cassia cinnamon to combat diabetes. This dose would yield about 800mg of Coumarin! There is some debate though that the steam distillation process used to encapsulate cinnamon for the "vitamin" market removes the coumarin.
Bottom Line: Deer Tongue and Tonka Beans are perfectly safe to consume in pipe tobacco as well as dip and snus.
