Blood test results for active THC delta 9 and for THC COOH and what that means

©Leonard Frieling 2018 Lafayette, Colorado

THC COOH (pronounced carboxy THC) is a metabolite of THC delta 9, the psychoactive cannabinoid in pot. THC delta 9 is commonly referred to as just THC, and the carboxy commonly referred to as THC COOH.
The COOH metabolite (made by the body FROM the active THC) takes a few hours to become present and detectable, and is thus arguably exculpatory. It is not psychoactive.
It is the chemical that for years, and in employment and other contexts has been the subject of the urine tests, and can be found for days, weeks, or even 105 days (longest I’ve read of).
Being lipid (fat) soluble it is the THC COOH that is stored in the fat cells and hangs around for a long time. Since urine sampling and testing is cheap and simple, an employer can use it to fire someone,
even though the smoking may have been only on Friday nights with no employment until Monday, and never within any possible impairing time of work.

Impairment generally is gone after 3-5 hours in most people. Some regular smokers (vaporizing being a better alternative) show levels of ACTIVE THC and no impairment days after not smoking.
While some experiments have shown 0.5 ng/ml active whole blood after a day or two, and up to 1.5 ng/ml active THC in blood after 5 days, and some claim much higher numbers after even more time,
I believe no respected researcher claims impairment after 6-8 hours. Also remember that degree of impairment, while it increases with greater intake, does NOT correlate to level of impairment.
A person with 5 ng/ml active THC whole blood (which is what our current (Colorado) law looks at, with NO mention of COOH) might not be impaired at all, while another might be impaired at 3 ng/ml.
It seems to vary with many things including the experience of the smoker. In other words, if a person smokes one joint, and is impaired, they will be more impaired after two joints.
But the blood-THC measure does not tell us whether or not they are impaired, or how impaired they might or might not be.

For alcohol, drink twice as much and you are more impaired. AND we can say some things about impairment based upon the blood level generally, with the information having meaning for people in
general; not just for a specific individual.

With pot, I think there are several factors. First, the max impairment occurs after (30 minutes to 1 1/2 hours) smoking/vaping. Active THC in blood peaks VERY VERY fast, reaching peak levels
within minutes of smoking a joint. It also DROPS very very fast in blood. Thus, the blood peaks long before the impairment peaks. This is referred to as counterclockwise hysteresis.
Second, as I said, the same number (active THC in blood) does not correlate to the same impairment in two different people.

There are some (not generally accepted stuff) who will testify that the ratio of COOH to psychoative THC delta 9, tells something about recency of smoking. That is utter crap.
WAY too many unknowns are missing, and would be necessary to draw such a conclusion.

In court, I have filed and will continue to file, when appropriate, a motion in limine to keep the COOH result excluded entirely since it has zero probative value. It is the same as a prosecutor
saying this defendant had wine within the last weeks or months, we don’t know when, we don’t know how much, and you should consider that in determining whether they were impaired by wine on the date/time of the charged offense.
That would never be permitted and this is no different.

If your active THC # is low enough, that supports the argument that it might have been higher earlier, and the COOH indicates that it had to be hours earlier for the COOH to be made from the
THC delta 9 THC, so the smoking had to be at least hours earlier, OR maybe days or weeks earlier, but you can’t get COOH until at least hours after the active THC is introduced into the body.

In addition, a side issue I’m dealing with.

When we have a second sample of our clients’s blood picked up from a state lab for testing by our private lab, that testing and the request for the sample should never be available to a jury.
If the request is in writing, as it normally would be, without protective steps, the litigation packet from the state lab may well include the defense request for the second sample.
That cannot be permitted, since the second test may be higher than the state’s test, or may confirm the State’s test. There are a number of strategies to avoid this problem.

Debunking Scientific Studies on Marijuana

How to Evaluate Studies on Marijuana Medically and Otherwise

©Leonard Frieling 2018 Lafayette, Colorado


We are bombarded by press touting studies which purport to show wonderful benefits provided by marijuana. We are similarly bombarded by studies which present alleged dangers associated with marijuana use. How do we evaluate studies? Do we want rely upon in debates and discussions; studies to parade at rallies which say what we want, regardless of the scientific validity of the work? Personally I am a fan of intellectual honesty first and politics second. Let the facts drive the politics. Let the science guide the law.

On politically charged subjects like marijuana and firearms for example, the disparity in study conclusions is radical.

How does someone tell how much weight should be given to a study and its conclusions? How do we evaluate studies? Scientists have specific mathematical tools for evaluating study reliability. For most of us, these technical validity instruments are beyond our skill sets. But there are many ways to help us evaluate studies without the experience and education needed to utilize the sophisticated tools available to scientist. This topic will be covered in a series of blogs, since it is complex and worthy of study.

First, is the study a “meta-study” or a “study?” A study deals with obtaining new data and analyzing the new data. A Meta-study is one in which no new data is obtained and no new experiments are done. Instead, previous studies are re-analyzed. The raw data is re-examined in light of the other studies being examined, and “new” conclusions are drawn.

Meta-studies, while not without value, should be viewed differently. First, while at first glance they may appear to be, and may be presented as new studies, they are not. They are in many ways, old news re-runs.

That leads directly to a major problem in trying to track marijuana science by reading the newspapers. It is common to see an old and frequently weak study be trotted out as “new.” In fact, GIGO, “garbage in garbage out” is the fact. A weak study does not become a strong study because it has aged.

Second, who did the study? Who financed the study? It is no surprise that the studies glommed onto by law enforcement organizations, some police chiefs, and others, were financed or conducted by, written by, or interrupted by law enforcement or by other groups who potentially have agendas. Science and politics should not be the same thing. While science may guide legislation, study outcomes should not be results-driven. A study should not be undertaken if the goal from the outset is to prove that marijuana is harmful, or that it is not harmful.

Finally, in the “Big Three,” studies will generally end with statements suggesting what future research is needed or suggested. While many like to say “we need to study this more,” the reality is that while additional study is almost always good, the implied lack of historical studies is frequently the opposite of the truth. Studies should lead to more questions. That does not mean that the study provides no answers or guidance.

For example, the oft-repeated chant “we need more studies” regarding marijuana medically and otherwise is true. What it implies, that we don’t have many studies already, is the opposite of the truth. For example, is an index of studies in the medical fields. Some are available free, while others provide a free summary and the ability to purchase the full study. Search pubmed for “aspirin” and 63,000+ studies are listed. Search for “marijuana” and 29,000+ results are available on this site. This makes two points. First, those that argue “we haven’t studied marijuana enough” are ignoring the fact that there may be almost half as many studies as for aspirin. Additionally the sheer number of the published studies on pubmed for marijuana is huge. Of course we need more study. And we simply cannot ignore the vast body of what has already been studied. More studies are needed in astrophysics. Does that suggest we know nothing currently?

What is the population studied? Is it ten subjects or 10,000? Is it over a period of a month or a longitudinal study over decades or even over generations? What is the source of the population? Are they properly screened for drug history or does the study rely upon the subjects accurately reporting their drug use, past and present? At least two studies which keep surfacing in the press persist in claiming damaging mental health from marijuana use. Both studies focus on a population suffering from severe mental illness.

Final suggestion for this Part I: READ THE STUDIES. While some are quite challenging and involve complex use of statistical analysis and extremely challenging vocabulary, many are sufficiently accessible so that even without understanding every word, reading the study is well worth the effort.