Cannabis edibles are ingested products, such as gummies, brownies, or beverages, that contain cannabis extracts. Consuming edibles can cause an increase in heart rate, a condition medically described as tachycardia. This physiological response is a common effect of the primary psychoactive compound in cannabis, Delta-9-tetrahydrocannabinol (Delta-9-THC). While this cardiac response is usually temporary, it can be surprising or alarming, particularly due to the unique way edibles are processed by the body.
Why THC Increases Heart Rate
The physiological increase in heart rate is directly linked to how Delta-9-THC interacts with the body’s internal signaling system, known as the Endocannabinoid System (ECS). Delta-9-THC works by binding to specific proteins called Cannabinoid 1 (CB1) receptors, which are abundant not only in the brain but also in the peripheral tissues, including the cardiovascular system. When THC activates these receptors, it triggers a cascade of effects that impact heart function.
This activation initiates a response from the sympathetic nervous system, often called the “fight or flight” response. The sympathetic nervous system is responsible for accelerating heart rate and increasing the body’s overall state of alertness. This can result in an acute, dose-dependent rise in heart rate, which may be up to 30% higher than the resting rate.
Low doses of THC may cause a temporary drop in blood pressure due to vasodilation. This is followed by a reflex increase in heart rate to compensate. This increase in heart rate and sympathetic tone is the body’s mechanism for ensuring adequate blood flow and is the primary reason why consumers experience palpitations or a racing pulse.
The Unique Pharmacokinetics of Edibles
The experience of heart rate elevation with edibles can feel more intense or prolonged compared to inhaled cannabis because of the unique way they are metabolized. When cannabis is eaten, the Delta-9-THC is absorbed through the digestive tract, a process that is significantly slower and less direct than inhalation. This results in a delayed onset of effects, which can take anywhere from 30 minutes to two hours before any psychoactive or physiological changes are felt.
Once absorbed, the THC travels to the liver, where it undergoes extensive first-pass metabolism. During this process, the liver enzyme system converts a significant portion of the Delta-9-THC into a different compound called 11-hydroxy-THC (11-OH-THC). This metabolite is highly psychoactive.
The presence of 11-OH-THC is why edible effects are often described as more intense and sustained. Research indicates that 11-OH-THC is significantly more potent than Delta-9-THC, with some estimates suggesting it is two to three times stronger. Furthermore, this metabolite is more effective at crossing the blood-brain barrier, contributing to the profound and long-lasting effects on the central nervous system and the cardiovascular system.
Peak concentrations of 11-OH-THC typically occur around 1.5 to 2 hours after consumption, coinciding with the peak intensity of the edible experience. This metabolic pathway creates a delayed, potent, and sustained exposure to a highly active compound, leading to a more pronounced and durable period of heart rate elevation.
What to Do If Your Heart Rate is High
Experiencing a rapid heart rate, or racing pulse, after consuming an edible can cause significant anxiety. The most immediate and important step in managing this sensation is to remain calm and recognize that the condition is generally temporary and self-limiting. Moving to a quiet, safe environment and engaging in slow, deep breathing exercises can help to reduce anxiety and temper the sympathetic nervous system response.
Maintaining adequate hydration is also beneficial, as is distracting the mind from the physical sensations. The effects will gradually subside as the body processes the THC and 11-OH-THC metabolite. For most people, supportive self-care is sufficient until the acute effects lessen.
When to Seek Medical Attention
However, there are specific warning signs that necessitate seeking emergency medical attention. If the rapid heartbeat is accompanied by severe chest pain, difficulty breathing, or significant changes in mental status such as extreme confusion, immediate medical evaluation is warranted. Individuals with pre-existing heart conditions should also seek professional care if they experience a persistent and unusually rapid heart rate. Medical professionals can provide supportive care and monitoring to safely manage the cardiovascular effects.