What is THC?
Tetrahydrocannabinol (THC) is a psychoactive substance that activates the feel-good neurons in the brain to produce a ‘high.’ It is classified as a cannabinoid as it’s the primary component of cannabis that interacts with the body’s endocannabinoid system to influence the user’s memory, thinking, pleasure, coordination, and time perception.
While THC is detectable in different bodily fluids, knowing how it works and its influences on the body is imperative.
How does THC work?
THC is contained in industrial hemp (also Indian hemp or Cannabis sativa), marijuana, and hashish, although in relatively different amounts. All these are a variety of cannabis grown for various purposes.
Cannabis grown for hemp has smaller amounts of THC than that grown for the production of hashish or marijuana. Once ingested, THC binds to the cannabinoid receptor type 1 (CB!) receptors in the brain to produce a feeling of euphoria.
Effects of THC include:
- Relaxation.
- Paranoia
- Altered perceptions of space and time.
- Dry mouth
- Red eyes.
- Increased appetite.
- Sometimes, anxiety and hallucinations.
THC is consumed in cannabis-infused edibles, such as baked goods, candies, and drinks. It is also contained in products such as essential oils, tinctures, topicals, and flowers.
Another well-known cousin to THC is the cannabidiol (CBD) compound found in cannabis, and the difference between the two is that CBD is not psychoactive. It, therefore, does not give a ‘high.’
Uses of CBD
CBD is the compound exploited in cannabis for its therapeutic effects, including:
- Controlling seizures.
- Reducing pain and inflammation.
- Reducing anxiety and depression.
- Improving sleep quality.
- Preventing neurodegenerative diseases.
Unlike THC, CBD does not bind to the CB1 receptors once ingested. The effects of both compounds may vary widely depending on the mode of consumption, dose taken, and individual tolerance.
When consumed together, they produce a synergistic effect.
How long does THC stay in the body?
Several factors affect how long THC lingers in the body. They are:
- Frequency – individuals who abuse cannabis more frequently will have higher levels of THC in their bloodstream, meaning it would take longer to eliminate it.
- Dosage – how much you take influences the time it takes to eliminate THC and its metabolites from the bloodstream entirely.
- Mode of consumption – smoked or vaporised THC in cannabis is quickly absorbed through the lungs and into the bloodstream. There will be rapid absorption of THC, distributing rapidly throughout the body.
When ingested, THC is first taken to the digestive system, where it’s broken down into metabolites, which then enter the bloodstream and are distributed into various organs.
This means there will be higher concentrations of THC in the blood when smoked than when ingested.
- Metabolism rate – the faster THC is broken down into metabolites in the body, the faster it is eliminated from your system.
- Body fat percentage – cannabis users with higher body fat percentages have higher levels of THC. This is because THC is stored in body fat, which takes longer to eliminate.
- Hydration – keeping your body well hydrated will help flush THC metabolites from your system.
THC detection window
Various cannabis drug tests have varying detection windows. While the above-mentioned factors affect the detection window, the type of drug test conduction plays a key role.
Urine test
This is the most common testing method. THC is detectable in urine for more than 30 days after last use for a chronic user. For a light user consuming daily, traces of THC in urine can be seen between 10-15 days after last use.
One-time users risk detection up to 3 days since last use.
Blood test
Blood tests detect cannabis use within the last 2-12 hours of consumption. But, for heavy users, THC metabolites remain in the bloodstream for about 30 days after last consumption.
Saliva test
This test has a shorter detection window, usually within 72 hours from the last use. Like the alcohol blow roadside testing, cannabis saliva tests can also be conducted by the roadside using an oral fluid.
Hair test
Hair follicle tests detect drug use patterns for up to 90 days.
Now that we understand the working mechanisms of THC and detection methods in the body let’s learn about the risks of THC transmission during sex, breastfeeding and how to reduce exposure.
Can THC be transferred through bodily fluids?
Although there may be substantial traceable amounts of THC metabolites in blood, urine, and saliva, it can only be transmitted through semen, vaginal secretions, and breast milk.
Studies have revealed that THC is detectable in vaginal fluids, semen, and breast milk and can potentially be transferred from one person to another through these bodily fluids.
While there’s scientific evidence supporting the transmission of THC through bodily fluids, proof of the extent of transmission remains insufficient.
THC binds to fat cells in the body, increasing its chances of being stored for weeks, even months, after ingestion. This THC is released from the fat cells into the bloodstream and transported into bodily secretions during metabolism.
THC transmission through semen
During unprotected sexual activity, semen containing traces of THC comes into contact with the mucous membranes in the genitals, anus, or mouth. The membranes then absorb THC molecules and transport them to the bloodstream of the recipient.
However, due to the low concentration of THC in semen, it is unlikely that the traces transmitted are enough to cause psychoactive effects in the recipient.
A 2022 study shows that quantifiable traces of THC metabolites are detected in the semen of chronic users of inhaled cannabis.
THC transmission through vaginal fluids
Limited research is available on the presence of THC in vaginal fluids. However, studies show higher chances of detecting the compound in the vaginal fluids of women who had used cannabis in the past 24 hours of the test.
Similarly, it is somewhat unclear whether the amount transmitted is high enough to cause psychoactive effects in the sexual partner.
Risk factors for transmission of THC during sexual intercourse
- Unprotected sexual intercourse.
- The frequency and dosage of cannabis ingested by the sexual partners.
- Consistency of bodily fluids exchanged during sex since last use of cannabis.
- Some studies suggest using lubricants increases the absorption of THC through the mucus membranes of the vaginal lining.
- Presence of cuts, sores, or abrasions on the mucous membranes that increase the risk of THC absorption.
How to minimise the risk of THC transmission during sex
- Using condoms or other barrier methods that hinder fluid exchange during sex and, ultimately, prevent THC transmission.
- Open communication between sexual partners on cannabis use.
- Avoid sexual activity when open wounds, sores, or abrasions of the mucous membranes are present.
- Staying well hydrated before and after using cannabis.
THC transmission through breast milk
THC can be passed from a nursing mother to an infant through breastfeeding. As a fat-soluble chemical compound, THC has a high affinity to breast milk, which consists of 3-5% fat content. This fact is attributable to the longevity of THC in breast milk.
Chronic consumption of THC products can accumulate in breast milk in higher concentrations. Although it’s hard to determine how much of the intake is transferrable to a mother’s breast milk, studies suggest that lactating mothers who highly use cannabis transfer it to their infants in the ratio of 8:1
For regular or one-time cannabis-using lactating moms, their infants only consume 0.8% of the mother’s dosage.
How long does THC persist in breast milk?
How long THC metabolites stay in breast milk depends on multiple factors, similar to how long it stays in the body.
However, it is crucial to note that women’s bodies have more extensive reservoir storage for THC compared to men due to their high body fat percentage; about 25-30% of a woman’s body is made of fat.
This means that it would take longer for THC to thoroughly wash out of the system, thereby increasing its absorption into breast milk. Studies conducted in the test for THC metabolites reveal that the compound has a detection window of between 6 days to 6 weeks in breast milk.
Additionally, the mean half-life of THC in breast milk has been estimated to be 17 days. Nevertheless, for chronic lactating users, it is possible to detect THC metabolites in breast milk longer than 6 weeks after last use.
Effects of THC in breast milk
Although THC concentration in breast milk may not be high enough to cause observable ‘highs’ in the infant, the following can be a result:
- Irregular sleep patterns.
- Developmental delays.
- Feeding difficulties.
- Impaired cognitive function.
- Hyperactivity.
- Tremors
- Irritability.
Lactating mothers should shun cannabis use to avoid predisposing their babies to the side effects above. In addition, the mother should avoid breastfeeding when high and substitute breast milk with available formulas.
According to the American Academy of Pediatrics (AAP), lactating mothers should avoid breastfeeding for at least 2 hours after using. This should be followed by a pump and dump for the first stream of milk after cannabis ingestion.
Since cannabis has both therapeutic and psychoactive effects, its consumption by lactating mothers should be done under a doctor’s advisory and implement the following to reduce THC metabolites in breast milk:
- Use cannabis in minimal doses.
- Stay well hydrated.
- Exercise regularly.
- Never smoke or vaporize cannabis.
THC transmission through the placenta
Although little is known about the maternal-fetal transfer of THC, it is possible to pass THC metabolites to the fetus through the placenta.
As a lipophilic molecule, THC passes from the fat cells of the placenta into the fetal bloodstream. This is the only possible means through which THC is transmitted through the bloodstream.
THC exposure to a developing fetus has the following effects:
- It increases the risk of premature birth.
- Impairs fetal growth, hence reduced birth weight.
- Increases the risk of stillbirth.
- Impairs fetal brain and nervous system development, which may lead to cognitive impairment, attention deficit hyperactivity disorder (ADHD), and autism in the newborn.
Besides these neurodevelopment disorders in the fetus, an infant born of a cannabis-using mother may exhibit neonatal abstinence syndrome (NAS).
These are a group of symptoms that occur in newborns exposed to certain drugs while in the womb. They include tremors, irritability, seizures, and feeding difficulties.
Pregnant women concerned about the risk of THC transmission to their unborn should see a doctor to help them understand the risks and benefits of cannabis and get support and guidance from qualified personnel.
