Beginner's Pharmacology

Written by Kamal Patel
Last Updated:

'Pharmacology' and the related terms Pharmacokinetics and Pharmacodynamics are popping up a lot on Examine, and the Editors have been informed that these terms are 'intellectually intimidating' to many. Basically, we've done a bad job on actually explaining what pharmacology is.

Pharmacology (Pharma- is in reference to drugs, which supplements are a less potent subset of) is just the study of drugs. Quite important, the other two terms are subsets of pharmacology.

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I have been informed of a much shorter, simpler, and more beautiful definition(s) and distinction between pharmacokinetics and pharmacodynamics.

Pharmacokinetics is what your body does to the drug; involving metabolism and excretion after absorption.

Pharmacodynamics is what the drug does to your body; involving enzyme interactions and metabolic changes.

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We're trying our best to make short summaries in the blue quoted blocks in each section, for example, please check out the Resveratrol page as it has an incredibly in depth Pharmcology section with several quoted blocks for summarization.

As for some select terms commonly seen:

  • Bioavailability: This is a measure of how much is absorbed in the intestines and floats around in the blood; it is a percentage. If you ingest 1g of a compound and all that gram is found in the blood, bioavailability is 100%. If only 200mg is found in the blood and the rest is stuck in your colon, then it has a bioavailability of 20%. More often than not, a higher bioavailability is better. You get more of the compound.

  • Cmax: The C stands for concentration, and the max is the max value. Cmax is simply the highest concentration that is found. If looking in the blood, you have a serum Cmax of (eg. 45nmol/L). This tends to be related to the dose of the compound in some manner.

  • Tmax: The T stands for Time, this is simply when the Cmax occurs. If the highest concentration occurs 30 minutes after ingestion, the Tmax is 30 minutes. This is usually when the compound 'hits' you, like when you notice the peak of caffeine

  • Half-life: The half-life is how long it takes for half of the compound to be either degraded (basic half-life) or pissed/pooped out (elimination half-life). This is important when we look at compounds like ecdysteroids where studies in cell cultures say that, over a 24 hour period, it is just as potent as Methandrostenelone (D-bol, an anabolic steroid); however, its half-life is 8 minutes. It is just as potent as D-bol for about 8 minutes, then it degrades.

  • AUC: Is area-under-curve. If you drew a graph with the Cmax on the vertical axis, and the Tmax on the horizontal axis, you can plot the half-life by how far along the horizontal axis it takes until the vertical drops by 50%. However, if you just calculate the Area under the Curve you just drew, you get the AUC. This is a measure of how long you are exposed to the supplement, and generally more AUC is better (some exceptions).

It can get more complex than this, and we'll try to include the greater complexities but with simple summaries. However, it would be prudent to understand the above.

Many supplements fail because they have bad pharmacological profiles. A good supplement is one that actually gets to the cells and stays there long enough to do things.