What topics does this cannabis study cover?

This study covers research on: THC, CBD.

Where was this research published?

Published in British journal of clinical pharmacology on August 27, 2026.

THC raises heart rate, while CBD+THC shows milder effects

Q: What did this research study find?

Both oral oils significantly increased *heart rate* in healthy adults.

Acute effects of THC and a CBD+THC combination on cardiovascular haemodynamics and respiratory muscle activity during loaded breathing in healthy adults: A randomized placebo-controlled crossover study.

British journal of clinical pharmacology • August 27, 2026 • Highly Relevant

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AI Summary

In a randomized, double-blind, placebo-controlled crossover study of 18 healthy adults, researchers compared oral THC oil, a CBD+THC oil, and placebo. Both cannabinoid oils increased heart rate. The THC-only treatment also increased cardiac index at 60 and 150 minutes after dosing and lowered the vascular resistance index during demanding breathing and recovery.

The treatments also changed breathing-related muscle activity. THC produced stronger activation of several respiratory muscles during inspiratory loading, while the CBD+THC combination caused increases in activity in a different, more limited pattern. Changes in peripheral tissue oxygenation were more apparent with THC, although one measure did not reach statistical significance. Overall, the abstract concludes that acute THC effects were more pronounced, while CBD+THC produced a more attenuated cardiorespiratory response. These findings describe short-term responses in healthy adults and do not establish longer-term effects or effects in people with cardiovascular or respiratory conditions.

💡 Key Findings

Both oral oils significantly increased heart rate in healthy adults.

Good

75%

THC produced stronger cardiovascular changes, including increased cardiac index at 60 and 150 minutes and lower vascular resistance during breathing overload and recovery.

Good

72%

THC increased activation of several respiratory muscles during inspiratory loading, while the CBD+THC combination showed a more limited activation pattern.

Good

70%

Overall, THC produced more pronounced cardiorespiratory responses, whereas CBD+THC was associated with a more attenuated pattern.

Good

70%

📄 Original Abstract

This study aimed to evaluate the acute effects of cannabidiol plus tetrahydrocannabinol (CBD+THC) and tetrahydrocannabinol (THC) oils on cardiovascular haemodynamics, respiratory muscle activity and peripheral tissue perfusion in healthy adults. In this randomized, double-blind, crossover trial, participants received orally administered CBD+THC oil (12.5 mg + 12.5 mg), THC oil (12.5 mg) or placebo. Cardiovascular haemodynamics, respiratory muscle electromyography and peripheral tissue perfusion were evaluated during breathing tasks. Eighteen individuals were evaluated (26 ± 5 years). Both oils significantly increased heart rate (HR) (p < 0.05). Cardiac index significantly increased in I-THC at 60 and 150 min postdose (p < 0.05). The vascular resistance index was lower in the I-THC, with significant differences during respiratory overload and recovery (p < 0.05). A significant increase in activity of the sternocleidomastoid (SCM) and parasternal (PARA) muscles was observed in the I-THC during inspiratory loading at 60 and 150 min after dose (p < 0.05). In the I-CBD+THC, increased activation was observed in the scalene (ESC) and PARA muscles (p ≤ 0.021). HHb levels showed a descriptive decrease, particularly during inspiratory loading and recovery in the I-THC group, without reaching statistical significance, whereas O2Hb showed a significant increase during inspiratory loading in the I-THC group (p < 0.05). Acute administration of THC and CBD+THC oils induced distinct cardiorespiratory responses in healthy individuals, affecting cardiovascular haemodynamics, respiratory muscle activation and peripheral tissue oxygenation. THC produced more pronounced physiological responses, while CBD+THC was associated with a more attenuated pattern.

Paper Type

📄 Research

Publication

Journal: British journal of clinical pharmacology
Published: August 27, 2026
PMID: 42660566
DOI: 10.1002/bcp.70793

Authors (10)

Edna Karla Ferreira Laurentino PneumoCardioVascular LAB/HUOL, Hospital Universitário Onofre Lopes, Departamento de Fisioterapia, Universidade Federal do Rio Grande do Norte, Natal, Brazil.
Marina Lyra L C Fagundes PneumoCardioVascular LAB/HUOL, Hospital Universitário Onofre Lopes, Departamento de Fisioterapia, Universidade Federal do Rio Grande do Norte, Natal, Brazil.
Bruno Lobão Soares Departamento de Biofísica e Farmacologia, Universidade Federal do Rio Grande do Norte (DBF/UFRN), Natal, Brazil.
Rodrigo Torres-Castro Departamento de Kinesiología, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
Matias Otto-Yañez Grupo de Investigación en Salud, Funcionalidad y Actividad Física (GISFAF), Kinesiología, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile.
+5 more authors