Cannabis consists of many different compounds that influence our bodies in multifaceted ways, but perhaps the most misunderstood aspect is how and where they accumulate following consumption.
Cannabinoids are Lipophilic Compounds
THC (tetrahydrocannabinol), CBD, (cannabidiol), and all the other well-known cannabinoids are all fat-soluble molecules, or what researchers refer to as lipophilic compounds. Water-soluble molecules can be readily eliminated from the body, but lipophilic compounds ionically bond to lipophilic molecules in the fat tissues of our body’s various extraction systems.
Patterns of Distribution Throughout Body Systems
When cannabis enters your bloodstream—through inhalation, oral consumption, or topical application—the cannabinoids immediately start to distribute throughout the body. Cannabinoids prefer to accumulate in specific locations throughout the body’s extraction systems.
Adipose tissue (body fat) accounts for the main reservoir of storage, where cannabinoids can be stored for sustained periods of time due to the vast body fat characteristics; the brain represents yet another storage system that largely stores cannabinoids due to the fat mass represented. The cannabinoids affect the brain in a psychoactive way; and when the cannabinoids are removed from the body during the elimination phase of the cannabinoid pharmacokinetics, they have the potential to still affect the brain. The liver, lungs, and kidneys are significant organs of metabolic activity with high blood flow and will also process and eliminate cannabinoids but may retain a trace of cannabinoids from prolonged use.
Interestingly, hair follicles will incorporate cannabinoids into their compounds during the growing phase; therefore it is possible that habitual cannabis use creates a lasting time stamp in your hair. Even though they cannot produce physiological effects, bones with marrow rich in fat may also show chronic cannabis usage through the incorporation of cannabinoids.
Temporal Dynamics of Metabolic Clearance and Excretion
Cannabinoids are mainly metabolically processed via the liver. Each of these metabolites may enter enterohepatic circulation, where they progress to the liver and enter bile, flow into intestines, and possibly be reabsorbed back to the bloodstream to prolong meet bodily retention.
The duration of metabolites may vary considerably based on a variety of factors, such as:
- Pattern of use: Occasional users may expect to flush THC or metabolites in days, frequent or chronic users maybe months of traces persist.
- Metabolism: Individuals with faster metabolic rates would eliminate cannabinoids faster than slow metabolic rate individuals.
- Body fat: Individuals with greater body fat may have more sites for cannabinoids to be stored.
- Hydration: Appropriate hydration would support better metabolic efficiency.
- Exercise: During physical activity fat is mobilized reducing fat storage while releasing stored metabolites supports further elimination.
- Age and health: Age and general health considerably affect metabolism and therefore availability or duration of cannabinoids.
Clinical and Practical Considerations
The effects of drug testing related to cannabis use and likelihood of reporting a positive test is perhaps the most relevant of practical considerations. Blood tests may detect active THC for hours to days after use, whereas urine samples may report metabolites in days to weeks, and hair samples may suggest evidence of use accounting for months, because of the bio-accumulation properties of these compounds.
A similar analysis to accumulation is seen in tolerance, where the presence of cannabinoids in body tissues may down regulate cannabinoid receptors, thereby decreasing responsiveness to the same dose over a period of time. Many regular cannabis consumers will utilize cannabis tolerance breaks to re-balance a cannabinoid equity.
Longitudinal Health Considerations
Human studies analyzing adipose tissue in chronic consumers have detected THC metabolites released during fasting or “big time” weight loss that have been mild psychoactive effects, or reported positive tests for THC, without recent use.
Cannabinoids do not bioaccumulate forever. Whether the heavy consumer or infrequent consumer, a very complete excretion will ultimately take place, typically occurring within 30-90 days of cessation.
Research is evolving and better understanding of bio accumulation is forming a knowledge base for patients and consumers to make informed decisions about consumption patterns and the potential physiological effects before, during and after use.