Is it possible to display the effect of taking for example Prozac on level of Serotonin and other neurotransmitters/hormones in the body?

More generally speaking s is it possible to say: taking 1mg of medication A increases hormones B and C within 3 months by 2 units for the majority of people? or perhaps not this accurate but by some accuracy?

or taking food A, increases hormones C and D?

In other words is it possible to quantify the effect of any drug/food to the body?


3 Answers 3


Yes it is possible, but it is difficult. The way it would be done currently is to insert a needle into the base of your spinal cord to measure the concentration of a metabolite of serotonin, 5-HIAA, in the fluid surrounding your brain.

It is also possible to measure levels of this metabolite in saliva, urine, or in the bloodstream, but these measures would not necessarily represent the levels of serotonin in your central nervous system (brain). This is because serotonin plays a role in other (non-brain) bodily functions, and serotonin can not cross the blood-brain barrier. In other words, only serotonin that has been produced in the brain can be used by the brain.


Yes but antidepressants are in a class of their own! We do measure the serotonin, etc in R&D and food consumption and various other lists of increasing the drug and decreases in the body and gathered during clinical trials in the FDA and then continually monitoring is part of the process of legalization and why you see some drugs suddenly pulled from the market. But the brain is still the least understood part of the body in the medical community. The most commonly prescribed antidepressants are currently SSRIs, preventing serotonin,5-HT, from being reabsorbed, as their name, selective “serotonin reuptake inhibitors”, indicates. That resulted in all black box suicide warnings via the FDA bc we just don't know nor understand enough about them and our brain to predict their unpredictable behavior.For example Brintellix,the newest version of the SSRI and It is different enough from the welter of SSRIs currently available that it’s not simply a ‘me too’ drug. By its developer’s own admission, no one knows what effects are produced by 5 of the 6 functions Brintellix was designed to cause. But we do know that the 6th function, serotonin/5-HT reuptake inhibition, ( may cause suicidal behavior in a unique class of individuals:All of the other 5 functions interfere with normal brain activity—and the manufacturer admits that no one knows what those effects will be!Studies show Inexplicable violence, turned both inward and outward,( is the result of SSRIs causing a single change to brain function. )Brintellix causes several changes. These changes involve the handling of glutamate, which is a critical amino acid that’s required for brain function and cellular metabolism. Glutamate is necessary—at proper levels, in the right places, and at the right times—for learning, remembering, thinking, and emotions. It’s also involved in energy production throughout the body. Glutamate excites neural function. Too much glutamate can burn nerves out and too little keeps them from functioning properly. Not only does Brintellix manipulate 5-HT (serotonin), like all other SSRIs, it also manipulates 5-HT1A: Agonist,5-HT1B: Partial Agonist5-HT3: Antagonist 5-HT1D: Antagonist 5-HT7: Antagonist. An agonist triggers a response from a cell. An antagonist does the opposite. It blocks a cell’s response.No one knows what relationship exists between any of these neural receptors and Brintellix’s effect. No one knows what these manipulations of the brain will do to the body, intelligence, emotional state, sexuality, criminality, empathy, or anything in the future.So while it is available, it is not much help past the R&D process.

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    $\begingroup$ Although this answer seems correct, it's lacking in references, which is frowned upon on CogSci.SE. Adding references to studies for support would greatly improve the quality of your answer. $\endgroup$
    – Seanny123
    Apr 13, 2016 at 20:30
  • 1
    $\begingroup$ ... and some paragraphs. :) $\endgroup$
    – Steven Jeuris
    May 9, 2016 at 11:08

It sounds like you are interested in the "Quantified self" movement, which deals with self knowledge about one's body function. While this is not a comprehensive answer, there are a few things to consider:

1) Many hormone levels follow diurnal (24hr) cyclical patterns, and vary throughout the day. Sleep schedule (wake/bedtime) affects these cycles. This taking single measurements at different times of the day would give you very different results.

An example of sleep pattern (black bar is sleep relative to 24 hr time), wake up times would affect hormone levels at different times. enter image description here

2) There are seasonal variations in hormone levels (for example these control white/brown fur color in animals living around arctic circle). As such, your 3 month study needs to account for the change in seasons, and may be heavily influenced by natural changes.

3)There were a number of startups trying to sell hormone testing kits like this one to general public, however these are expensive and "not intended to treat, diagnose, etc". In short, without your own lab, it's really hard for an average person to get this kind of info. A doctor can prescribe a single time test, but those can easily cost hundreds of dollars and are not very descriptive, as the "normal" ranges they give are ridiculously broad (for example testosterone is at range 270 to 1070ng/dl)

4) While it's common to hear popular science refer to "serotonin or dopamine flooding the brain" - ask yourself, where is this flooding occurs? As such, where do you actually measure these changes? I still can't find a clear answer to these questions.

My personal research into sleep makes me hypothesize that one can get an impression that something is changing in the serotonin/dopamine/testosterone system by looking at the duration, clarity and content of one's dreams.


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