5-HTP May Help You Be More Assertive

5-HTP May Make You A Better Person
Sound too good to be true?
See how a chemical compound can induce desirable personality traits.

We can learn a lot from monkeys. Aside from being so darned cute and funny to watch as they scamper about, doing their monkey business, they can teach us things about ourselves that we may not know, but probably should - things about aggression and quarrelsomeness, for example, and what may cause them, and how to temper them. Monkeys share about 92% of their genes with us, and it has never been a secret that they are very much like us in many ways, some good and some not so good.

Among the aspects of monkey behavior that have long fascinated humans who study them is their social organization - how individual behaviors mold the structure of the group, and how group dynamics affect the roles of the individuals. Key to all this, of course, is interpersonal - or rather, intermonkey - interactions. How do they get along? What makes them depressed and moody, or happy and frisky? How do they deal with anger or jealousy? Why do they fight, and how do they make up? Who's the boss, and how did he or she get to be the boss?

There are many questions, all of them just as relevant to ourselves as to our furry little friends. Two questions that might not have occurred to you are: What happens when they, or we, take tryptophan? What if we took 5-hydroxytryptophan (5-HTP) instead? We'll get to those questions, because they can shed light on some of the most basic aspects of social interactions in both man and beast.

Serotonin Is Key to Our State of Mind

Ultimately, the answers to all questions regarding mood and behavior can be found in brain chemistry. That's easy to say, but it's very hard to actually do, because the brain is so complex. Everything we think and feel and do is the direct result of electrochemical processes in our brains, so neuroscientists spend their lives trying to figure it all out - with some notable successes thus far.

One such success was in deducing the varied functions of serotonin, a brain neurotransmitter that plays vital roles in such monkey and human phenomena as the regulation of aggression, anxiety, appetite, depression, and sleep. Not that the job of deducing serotonin's roles is complete, however (far from it), but progress is being made toward a better understanding of what it does, and how it does it. This article is about one recent step along the way - a step facilitated by the use of an essential amino acid called tryptophan.*

*An essential amino acid is one that we can obtain only through food, because our bodies cannot synthesize it.

5-HTP Leads to Serotonin

Tryptophan is a precursor of serotonin, via an intermediate compound called 5-hydroxytryptophan (5-HTP), which is also an amino acid. In other words, tryptophan (not all of it, but some of it) is converted in our bodies to 5-HTP, and 5-HTP (some of it) is converted to serotonin. So some tryptophan winds up as serotonin, and if we take supplemental tryptophan, therefore, our serotonin levels will rise.

Thankfully, Tryptophan is again available as a supplement. And 5-HTP, being "adjacent" to serotonin in the biochemical pathway, also raises serotonin levels. (It also raises tryptophan levels somewhat, because all chemical reactions go in both directions - with one direction predominant in almost all cases, however.) Thus, in the research described below, it is valid to assume that the effects attributed to tryptophan would also have been brought about by 5-HTP if equivalent amounts of that amino acid had been used instead.

Monkeys Do, Humans Do?

Psychologists at McGill University in Montreal were intrigued by research on the effects of increased serotonin levels in monkeys, as induced by the administration of tryptophan. It had been found, for instance, that serotonin levels are related to dominant and submissive behaviors, and these are vital factors in group dynamics and the social order. In particular, higher serotonin levels are associated with social dominance, and lower (but not necessarily subnormal) levels are associated with submissiveness.

Are these effects the same in people as in monkeys? The researchers decided to test the hypothesis that tryptophan would have positive effects on human social interactions in healthy people, as opposed to those suffering from, say, depression or anxiety (for which it was already known that tryptophan is beneficial).



Can 5-HTP Mitigate Aggressiveness?

We know from other studies that serotonin levels play a major role in aggressive behavior in both animals and humans (the McGill researchers cite the literature on this subject). In monkeys, low levels of serotonin are associated with aggression, including pathological aggression, and this effect has been observed in humans too.

In terms of the two axes of social interaction described in this article, aggressiveness is a complicated behavior, in that it has elements of both dominance (in a highly negative, unhealthy sense) and quarrelsomeness (taken to extreme levels). Thus it does not lend itself neatly to an analysis in those terms.

What is interesting, in any case, is the serotonin connection, especially the finding that deliberately inhibiting serotonin synthesis in humans, by reducing tryptophan (and thus also 5-HTP) levels, increased aggressiveness during laboratory tests. In other studies, administering tryptophan to pathologically aggressive individuals reduced their aggressiveness or reduced the need for drugs to control it.

Low levels of serotonin are also associated with the self-directed aggression of suicide, and in particular with violent suicide.

Low serotonin. Pathological aggressiveness. Violent suicide. . . . September 11.

Could something—anything—have made a difference? One can only wonder . . . and weep.


A Simple Model of Social Interactions

Social interactions, or interpersonal behaviors, can be thought of in terms of a simple conceptual model consisting of a circle with two major axes:

1. Status axis. The principal behaviors here are dominance and submissiveness. They indicate the status, or power, of an individual in relation to others. It should be noted that dominance here is meant in the sense of assertiveness in a positive, healthy way, such as that exercised by a strong person with a capacity for leadership.

2. Affiliation axis. The principal behaviors here are agreeableness and quarrelsomeness. They indicate the level of affiliation, or communication, between individuals as a means of cementing their relationship and getting along with each other.

These are oversimplifications, of course - social interactions are fraught with subtlety and complexity, and each layer of meaning can conceal another layer representing a different shade, with different implications. Aspects of behavior on one of the axes in this scheme can overlap and affect those on the other. Nonetheless, much research has shown that the division of behaviors along these lines is generally valid and can provide useful guidelines for understanding human interactions.

The McGill Experiment

For their experiment, the McGill researchers recruited 98 healthy volunteers (humans, not monkeys) and divided them into two groups.1 One group received 1 gram of tryptophan with each meal daily for 12 days, while the other group received a placebo. Then, after a two-day "washout" period with no supplements, the pills for the two groups were switched, and they took the same doses for another 12 days. This "crossover" method, by which each group winds up receiving both treatments, is designed to balance out differences that may exist between the two groups in the way they respond to the treatment. The protocol was double-blinded, so neither the participants nor the researchers knew who got what, when, until the study was complete.

During the treatment periods, the participants were required to fill out forms recording the nature of their social interactions and behaviors throughout the day, thus providing the raw data for the study. (To see how this was done, see the sidebar "How Do You Measure Behavior?")


How Do You Measure Behavior?

Acquiring data on behaviors in a manner that will allow a quantitative evaluation and comparison is not easy, as one can well imagine. In order to make a meaningful analysis possible, the participants in the McGill experiment were required to keep meticulous records, through preprinted forms provided by the researchers, of the details of their social interactions and their behaviors and feelings throughout the day.

For each social interaction of any significance, for example, the participants had to document whether it occurred at home, at work, or somewhere else, and whether it involved a romantic partner, a family member, a friend, an acquaintance, someone at work (higher level, same level, or lower level), or someone else. Also, they were asked to record whether they had consumed alcohol during the hour before the interaction took place - just imagine what a difference that could make! All such alcohol-tainted data (4.7% of the interactions) were discarded. The participants were not users of any mind-altering drugs - a good thing.

The researchers defined a total of 46 different behaviors that the participants could specify on their forms. Here are some examples of agreeableness: "I smiled and laughed with others." "I compromised about a decision." "I complimented or praised the other person." Quarrelsomeness was recorded by statements such as: "I made a sarcastic comment." "I gave incorrect information." "I showed impatience."

Evidence of dominance was obtained through statements such as: "I asked the other person to do something." "I voiced an opinion." "I set goals for the other person." (Clearly, these behaviors represent healthy assertiveness, not bullying.) Evidence of its opposite, submissiveness, came from statements such as: "I gave in." "I avoided taking the lead or being responsible." "I did not express disagreement when I thought it."

There was a lot more to it than that, in terms of data collection and analysis, but you get the idea: the researchers were trying hard to quantify the essentially unquantifiable in as rational a way as possible.


Tryptophan Increases Healthy Dominance and Decreases Quarrelsomeness

When the smoke cleared from the statistical analyses of the data, the most important result of the study was that tryptophan significantly increased both the average level and peak level of dominant behaviors on the status axis - a healthy outcome for anyone who doesn't want to be a doormat. The effect was evident in both men and women and was independent of the context of the social interactions, i.e., it was prevalent across the board. This result is consistent with the results of marathon observations of monkey behavior (it's almost impossible to get them to fill out forms).

At the same time, tryptophan significantly decreased quarrelsome behavior on the affiliation axis - again in both the average and peak levels measured - so even as the participants were becoming more assertive and self-confident in their social interactions, they were getting along better with others as well.

Another result of this study was a lack of evidence that tryptophan elevates mood by raising the serotonin levels in healthy subjects. This squares with our knowledge that antidepressant drugs do not usually raise the mood of healthy subjects, nor do euphoriants (drugs that tend to produce euphoria) usually have antidepressant effects in depressed patients.

5-HTP Relieves Depression, and More

We know from much previous research, however, that depressed individuals feel better when their serotonin levels are increased by taking 5-HTP. As a natural supplement derived from the African plant Griffonia simplicifolia, 5-HTP is an ideal way to obtain the benefits of increased serotonin. These benefits include relief from mild to moderate depression, the alleviation of anxiety, the prevention of migraines, the inducement of sleep, and the reduction of carbohydrate cravings, among others.2 (For a discussion of the role of serotonin in depression, see "5-HTP Can Lift Your Spirits" in Life Enhancement, March 2002. References to other articles can be found at www.life-enhancement.com.)

5-HTP May Give Your Personality a Boost

Who among us would not like to be a better, more fulfilled, more effective person? There are many ways, of course, but being more dominant (in the healthy, assertive sense) and less quarrelsome are surely two good ones. And taking 5-HTP is a good route to those objectives, judging by the results of the research described above. It won't necessarily turn you into a diplomatic leader of men, but it might just give you a surer footing in life - a new ability to bring out your natural talents and to get along better with those around you. If we all did that, the world would be a better place.


  1. Moskowitz DS, Pinard G, Zuroff DC, Annable L, Young SN. The effect of tryptophan on social interaction in everyday life: a placebo-controlled study. Neuropsychopharmacology 2001;25(2):277-89.
  2. Birdsall TC. 5-Hydroxytryptophan: a clinically effective serotonin precursor. Altern Med Rev 1998;3(4):271-80.