Natural dog calmers ingredients that might be found in effective calmers include tryptophan and certain B vitamins, most often B1 (thiamine), B3 (niacin) and B6 (pyridoxine). Certain forms of clay can also be found as an ingredient, sometimes the only one.
Tryptophan earns its place in calming supplements because it is a precursor of serotonin (5HT). This means it is a building-block from which serotonin can be manufactured in the brain.
Serotonin, which is a neurotransmitter, acts in the brain to reduce anxiety and promotes a mood of happiness, concentration, calm and relaxation. So why not just feed serotonin? Because it cannot pass through the blood-brain barrier.
There is an intermediary compound produced in the manufacture of serotonin from tryptophan called 5HTP, which does pass through the blood-brain barrier so would appear at first glance to have potential as an ingredient in a calming supplement. Unfortunately it can irritate intestinal linings when fed at effective levels, causing unpleasant side effects, whereas feeding tryptophan at effective levels does not.
Tryptophan has been proven to improve mood by boosting serotonin levels in the brain but care must be taken to administer it correctly for two reasons:
Secondly the level of tryptophan given must be correct, too little will not have a significant effect and too much will actually promote tryptophan breakdown in the liver.
Vitamin B6, often referred to as pyridoxine, helps to catalyse (it is a co-enzyme) the conversion of 5HTP to serotonin and therefore has a potential role to play in calming dogs.
Niacin, occasionally referred to as vitamin B3, justifies its inclusion in a calming supplement for three reasons. The first might seem a 'backwards' reason but it is correct thinking nonetheless. It is that tryptophan is used to make niacin, but it is a very inefficient process using a good deal of tryptophan to make not very much niacin. Thus by adding niacin directly in a supplement, the tryptophan present is 'spared' and therefore more is free to form serotonin and help to calm the dog.
Secondly niacin is a co-enzyme for the reaction that converts tryptophan to 5HTP and therefore it promotes the production of serotonin in the brain.
Thirdly niacin inhibits the enzyme that breaks down tryptophan in the liver and therefore it again, albeit indirectly, promotes the production of serotonin in the brain.
Vitamin B1, commonly referred to as thiamine, is a candidate for inclusion in calming supplements mainly because it plays a direct role in transmission of nervous impulses. There is considerable anecdotal evidence for its effectiveness in reducing anxiety in dogs. It has been demonstrated to improve concentration and reduce excitability in humans and the same appears to apply in dogs.
Other B vitamins may have a case for inclusion in calming supplements; in particular a case could be made for folic acid, vitamin B12 and biotin. However all the B group vitamins have a myriad of functions and it is important to put any specific role into an overall context.
Clay can be justified as an ingredient for a purely physical effect. It has a huge surface area and absorbs or 'mops up' toxins in the dog's gut. Bentonite clay was once a popular ingredient but there is a risk of dioxin contamination so sepiolite clay, which does not contain dioxins, is considered preferable by leading nutritionists nowadays.
Clay has been used as a the sole ingredient in some calmers in the past and the odd product remains today, but as with many fashionable products it has, for the most part, been superseded by more sophisticated supplements.
Magnesium is currently a fashionable ingredient in calmers and indeed it is the only ingredient in some calmers. Whether it is advisable to rely on just one ingredient when trying to correct over-anxiety is arguable.
The main role attributed to magnesium when trying to justify its inclusion in a calming supplement is that it has an important function in the transmission of nervous impulses, as does calcium. The requirement for magnesium may increase under stress and therefore it is prudent to include it as an ingredient in calming products. To rely on it as the sole ingredient however, is in my opinion, less likely to succeed than to use a product containing a wider variety of approaches to solving the problem.
MOS, which is an acronym for mannan oligosaccharides, are the dried cell walls of yeast, and because of their large, 'spikey' surface area they bond to pathogenic bacteria in the dog's intestines, taking them out in the faeces. By leaving the beneficial bacteria free to multiply, MOS indirectly helps to maintain a correct gut environment and therefore justifies inclusion in calming products.
FOS, which is an acronym for fructo-oligosaccharides, works as a pre-biotic, stimulating beneficial bacteria such as bifido-bacteria, in the dog's gut.
All the ingredients described are natural. Most of them interact with each other and can affect temperament in a complex and sophisticated way that includes feedback mechanisms, so considerable skill and experience is necessary to formulate a successful calming supplement.