A Natural Way to Unwind

It’s usually easy to raise our hands. We think about it and it happens.

It’s not so easy to raise the temperature of our hands. Willing it doesn’t make it so. The part of the nervous system that does what we tell it to is called voluntary. The part that usually does whatever it wants to is called the autonomic nervous system. It’s automatic. There’s two parts to this automatic nervous system. Part of it makes us hyper-alert and stressed, another part of it slows us down, relaxing us.

The sympathetic nervous system wakes us up. When we perceive a threat, the hypothalamus in the oldest part of our brain gives a hormonal kick to the pituitary. The pituitary delivers its own neuroendocrine kicks to nerve endings throughout our bodies which secrete norepinephrine (aka noradrenaline.) Another hormonal kick tells the adrenal glands to dump adrenaline into our bloodstreams. These hormones create the nervous “jump” we feel when startled or threatened, the hyper-aroused state called fight or flight.

The parasympathetic nervous system (PNS) calms us down. The parasympathetic helps us enjoy ourselves, digest our food, relax. One of the PNS’s principle neurotransmitters is serotonin. The body makes serotonin from tryptophan, an essential amino acid. 5-HTP is an intermediate step in the conversion of tryptophan to serotonin. That means it can activate the PNS and improve our moods.

Think of the sympathetic system as the gas pedal and the parasympathetic as the brake. The body’s designed so that it’s difficult for both to be going at the same time. They inhibit each other. We don't step on the gas and the brakes at the same time. The body thinks that way, too.

This means that when we turn up the PNS, the sympathetic nervous system goes to sleep. This is how SSRI anti-depressants work: they artificially slow down the rate at which serotonin gets reabsorbed by the nerves that release it. Slower reabsorption means more serotonin in the synapses which means a calmer mind.1

5-HTP is used to boost the parasympathetic and calm us down. Most commonly taken to induce or improve sleep, it also brings a gradually increasing sense of relaxed well-being as serotonin levels build up and stress-filled sympathetic neurotransmitters are inhibited.

One big advantage of relying on 5-HTP instead of SSRIs is that SSRIs overpower the body's natural control mechanisms for deciding how much serotonin is needed. This is a powerful way to affect moods quickly but eventually the neurons adjust by altering the way their receptor sites respond to serotonin. This can create side effects and an addiction to the drug. Using 5-HTP, on the other hand, simply supplies more of the raw material the body uses to make serotonin. The brain can still choose how much to make.

This helps with more than sleep. There’s evidence that one reason some of us crave carbohydrates is because we crave the serotonin low-protein high-carb treats like candy create.2,3,4 While it’s true that even small amounts of protein in a high-carbohydrate meal can interfere with tryptophan’s ability to pass through the blood/brain barrier, it’s also true that this competition is reduced by the insulin response to a high carb meal.5 This boost in serotonin can leave us yawning.6

A lack of adequate serotonin has been implicated as a cause of at least some cases of depression. While there’s some debate about the precise mechanisms involved (caused in part by the 2-3 weeks it takes increased serotonin levels to affect many people’s moods7) for most of the time more serotonin means better moods.

There’s more. For the last ten years researchers have been able to take pictures of the brain while it’s at work. One of the foremost researchers in this area is a psychiatrist named Daniel G. Amen, M.D. He’s taken literally thousands of pictures of the activity in the brains of people presenting themselves for treatment at his clinic. He’s convinced that by calming overactivity in the hypothalamus and the cingulate gyrus, two brain structures involved in mood stabilization and flexible thinking, increased serotonin levels make us more adaptable to change and stress. In essence, 5-HTP and its metabolite serotonin help us change our minds. Dr. Amen feels that people who get stuck on a thought and can’t release it, who see the world in black and white, who hold grudges; those who get stuck in obsessive patterns of thinking and behavior—all would benefit from higher serotonin levels.8

(Important note: if you’re pregnant, nursing, or taking prescription anti-depressants check with your physician before taking 5-HTP as it can have adverse interactions with some medications and its effects in pregnancy are still being investigated by researchers.)


 1. For an excellent readable discussion of the way all this works, the modern classic is Why Zebras Don’t Get Ulcers, by Robert Sapolsky. New York: W.H. Freeman and Co. 1998. pp. 22-24.

 2. Fernstrom, J.D. 1988. Tryptophan, serotonin and carbohydrate appetite: Will the real carbohydrate craver please stand up? Journal of Nutrition. 118:1417-1419.

 3. Pollack, J. D. and N. Rowland. Peripherally administered serotonin decreases food intake in rats. 1981. Pharmacology, Biochemistry and Behavior. 15:179-183.

 4. Jonnakuty, C., Gragnoli, C. 2008. What do we know about serotonin? J Cell Physiol.. 217(2):301-6.

 5. Spring, B. 1984. Recent research on the behavioral effects of tryptophan and carbohydrate. Nutrition and Health. 3(1-2):55-67.

 6. Spring, B.J. et al. Effects of carbohydrates on mood and behavior. 1986. Nutrition Reviews. 44 (Suppl):51-60.

 8. Sapolsky, Robert. Ibid. 1998. New York: Freeman and Company. 239.

 9. Amen, Daniel. Change Your Brain, Change Your Life. 2000. New York: Times Books. 150-185.