What is it?

Amino acids are commonly known as the "building blocks of proteins". In other words they are the units from which proteins are constructed. Twenty two amino acids are required by the horse to manufacture proteins. The horse gets these from its diet or, if the diet does not supply sufficient amounts, the horse's body is capable of manufacturing about half of them. The amino acids which can't be manufactured by the horse are known as essential amino acids. These have to be supplied in the diet in sufficient quantities or protein synthesis cannot continue. This can cause different problems, depending on the role of the protein in question. Tryptophan is one of these essential amino acids.

What effect does it have?

Apart from being incorporated into proteins, Tryptophan is a precursor to the neurotransmitter, serotonin. When there is a deficiency of Tryptophan in the horse's diet, serotonin becomes deficient as well. This means that serotonin is unable to perform its function as a counterbalance to the hormones noradrenalin and dopamine. This can lead to anxiety, over-arousal, fear, anger, tension, aggression, violence, obsessive-compulsive actions, and sleep disturbances. So, supplementation with Tryptophan has been found to have a positive effect on a broad array of emotional and behavioural problems.

Controversy

In the late 1980's, a huge scandal erupted when Tryptophan was found to result in the illness, disablement and death of several people and animals. This was found to be traceable to one batch of Tryptophan, manufactured by a company called Showa Denko. Showa Denko was using genetically modified bacteria to churn out huge quantities of Tryptophan. It was later shown that these genetically engineered bacteria produced such huge quantities of Tryptophan that the molecules reacted with one another to produce the deadly contaminant called EBT. Since this problem was identified, quality suppliers of Tryptophan test every batch for EBT traces. (Note: the Tryptophan used by The Herbal Horse is certified to be completely free of EBT.)

Less is more

In the case of Tryptophan supplements, more is not always better. This is due to a liver enzyme called "Tryptophan pyrrolase" which breaks down Tryptophan. Tryptophan pyrrolase is known to be activated by increased intake of Tryptophan. So, the more Tryptophan is ingested, the more it is broken down. So, high doses of Tryptophan can actually have the opposite to desired effect of increasing anxiety! Thus, the lowest Tryptophan dose that successfully alleviates serotonin-deficiency symptoms is the most efficacious. (Note: The dose of Tryptophan provided by four scoops - the maximum dose - of The Herbal Horse's Calm mix extremely small and should never result in this feedback mechanism.)

Tryptophan and Prozac

I quote from an article called "The FDA Ban of L-Tryptophan: Politics, Profits and Prozac" by Dean Wolfe Manders, Ph.D:

"The fact that the FDA ban of L-Tryptophan and the Newsweek Prozac cover story occurred within four days of each other went unnoticed by both the media and the public. Yet, to those who understand the effective properties of L-Tryptophan and Prozac, the concurrence seems "unbelievably coincidental." The link here is the brain neurotransmitter serotonin - a biochemical nerve signal conductor. The action of Prozac and L-Tryptophan are both involved with serotonin, but in totally different ways."

The FDA has banned the use of Tryptophan - only in humans and only for the treatment of depression. It is perfectly legal to use in the treatment of animals. And it has been approved for the treatment of other diseases in humans (this would be impossible if it was harmful in any way). Manders believes that this is a blatant manipulation of the rules by the pharmaceutical industry in order to promote the use of the more expensive Prozac.

Is it good?

With all this controversy, it is understandable that some people are reluctant to use products containing Tryptophan. My views are:

• It is natural - supplementation with a small dose is correcting a deficiency in the diet, not "doping"
• It is legal - a naturally occurring substance which will not show up as a "drug of abuse" in urine or blood tests
• It is safe - the previous problem has heightened testing requirements, ensuring that each and every batch is completely free of EBT
• There are no side-effects when a low dose is used
• It is an affordable, safe, natural alternative to the much more potent tranquilising drugs often used in the horse industry