“All the medical benefits with none of the side effects.”
That’s the promise made by advocates for low-dose and ultra-low-dose consumption of marijuana — a.k.a. microdosing. This trend, made possible by a new generation of metered cannabis products that allow for precise dosage control of THC and other cannabinoids, was labeled “Marijuana 2.0” by Rolling Stone Magazine.
While critics of microdosing have dismissed the practices as “just an excuse to get high all the time,” there is a significant body of evidence to suggest that low-dose and ultra-low-dose administration THC can provide a number of therapeutic benefits. Additionally, both anecdotal evidence and clinical studies show that consumption of THC at these dosages does not produce the same short-term cognitive effects associated with high-dose THC consumption.
Defining Dosages
Prior to current legalization efforts, marijuana consumers had only vague notions of the actual of dosage of THC being consumed. Today’s standardized labeling takes much of the guesswork out of determining a preferred dosage, but variables remain. THC content in marijuana flower can vary from less than 1 percent to around 30 percent, but only a portion of that content becomes bioavailable to the user.
Research suggests that smoked marijuana provides an average bioavailability of around 30 percent. Based on that figure, an average-sized marijuana cigarette containing .5 grams of marijuana with a 10 percent THC content would deliver about 15 milligrams (mg) of THC to a user who consumed the entire cigarette. For research purposes, the National Institute on Drub Abuse and other research organizations have established 5mg as the standard unit of THC considered as a single dose.
Other research groups have settled on a 7mg standard. States have adopted similar standards, setting either 5mg or 10mg of THC as the standard dose for edible cannabis products. There is no current standard for what would be considered a “microdose” of THC at the consumer level, but a survey of websites and forums devoted to the subject reveals that dosages with THC thresholds below 5mg would fit this definition, and 2.5 milligrams also represents a common dosage.
Low-Dose THC May Promote Relaxation & Stress Relief
A study published in Drug and Alcohol Dependence noted that relaxation and stress relief are frequently mentioned as reasons for marijuana use. To test the potential stress-relieving properties of cannabis, healthy subjects were put through a series of tests designed to induce stress. Test subjects were given either a placebo, a 7.5 mg dose of THC, or a 12.5 mg dose.
Among the findings of this study were that:
- 5mg THC dampened negative emotional responses without influencing performance.
- 5mg THC slightly but significantly increased negative affect overall.
- 5mg THC impaired TSST performance and attenuated blood pressure responses.
This led the authors to conclude:
Our findings suggest that a low dose of THC produces subjective stress-relieving effects in line with those commonly reported among cannabis users, but that higher doses may non-specifically increase negative mood.
Low-Dose THC For PTSD
We have previously reported that CBD may block PTSD memories and there are indications that low-dose THC may also mitigate some symptoms of PTSD. A review of literature published in the journal BMC Psychiatry concluded:
At low doses, THC can enhance the extinction rate and reduce anxiety responses.
And that:
Current evidence from healthy humans and PTSD patients supports the THC value to suppress anxiety and aversive memory expression without producing significant adverse effects if used in low doses or when associated with CBD.
In a small-scale study of ten patients suffering from chronic PTSD and already on a stable medication plan, participants were given a twice-daily supplement of 5mg of orally-administered THC. The authors reported that supplementary treatment with THC created “statistically significant improvement in global symptom severity, sleep quality, frequency of nightmares and PTSD hyper-arousal symptoms,” and added that “orally absorbable delta-(9)-THC was safe and well-tolerated by patients with chronic PTSD.”
Microdosing Marijuana For Pain Relief
As we have previously reported, there is conclusive evidence that cannabinoids are effective for the treatment of chronic pain in adults. There is also evidence that low-dose THC formulations can provide pain relief without the intoxicating effects associated with higher-dose THC products. A double-blind study provided 27 patients suffering from chronic pain with a single inhaled dose of 0.5mg THC, 1mg THC, or a placebo. Pain intensity was assessed at measured intervals after administration, and each patient’s cognitive performance was evaluated using the Cambridge Neuropsychological Test Automated Battery.
The authors reported that:
- Both doses, but not the placebo, demonstrated a significant reduction in pain intensity compared with baseline and remained stable for 150 minutes.
- Adverse events were mostly mild and resolved spontaneously.
- There was no evidence of consistent impairments in cognitive performance.
In concluding remarks, researchers stated:
This feasibility trial demonstrated that a metered-dose cannabis inhaler delivered precise and low THC doses.
Low-Dose THC for Cognition & Brain Health
One of the more noteworthy developments in research into the medicinal benefits of low-dose THC is the potential to slow cognitive decline and enhance brain health in older adults. A number of animal studies have provided indications of these phenomena. A study published in the May 2017 edition of Nature Medicine stated that a “low dose of delta-9-tetrahydrocannabinol (THC) reversed the age-related decline in cognitive performance of mice aged 12 and 18 months.” The researchers also noted an increase in synaptic activist in test subjects, along with increased brain tissue density, and reported:
THC treatment restored hippocampal gene transcription patterns such that the expression profiles of THC-treated mice aged 12 months closely resembled those of THC-free animals aged 2 months.
A similar study involved old female mice (aged 24 months) that were provided a single 0.002 mg/kg dose of THC. This amount is about 1000th the dose typically used to study cannabinoid effects in mice. Treated mice were compared to untreated old mice and young mice for various aspects of memory and learning. The results showed that the treated mice performed significantly better than the untreated old mice, and on par with young mice, and that this enhancement lasted for at least 7 months. In addition, MRI scans revealed that treated mice exhibited a larger volume and higher tissue density in various regions of the brain as compared to untreated mice of the same age.
This led the authors to conclude:
Extremely low doses of THC that are devoid of any psychotropic effect and do not induce desensitization may provide a safe and effective treatment for cognitive decline in aging humans.
More specific suggestions for low-dose THC use were put forward in the concluding remarks of a paper published in the journal Aging. After describing the beneficial effects of administering a dose of 0.002 mg/kg THC to mice, the authors asked:
Can these surprising neuroprotective effects of ultra-low THC in mice be translated to clinical treatment in aging humans?
They went on to extrapolate an appropriate conversion of drug doses from experimental animals to humans. This conversion yielded a dose of 0.014 mg (or 14 micrograms) for an average patient of 70 kg body weight. This was noted as “an extremely low dose 100 times less than than the threshold for the conventional mental and somatic effects of THC.”
An explanation for the beneficial effects of THC on aging brains was included in a report from The American Journal Of Drug And Alcohol Abuse. The authors noted that at least a portion of the cognitive decline associated with aging was the result of “the accumulation of minor insults such as short episodes of hypoxia, transient seizures, micro emboli, exposure to neurotoxins, or local inflammatory events that occur during the lifetime.” They postulated that the neuroprotective effects of ultra-low THC might lessen these deleterious effects and trigger compensating protective and healing reactions.
Researchers concluded:
Ultra-low THC might be able to rescue the old brain and prevent, or even reverse, age-related cognitive impairments.