Table of Contents
CBD Dosage Medical Studies
These study summaries provide fact-based answers about CBD dosage and absorption.
- how CBD absorption can be easily boosted 380%
- safe CBD dosage tested across several studies
- how long CBD remains in the blood
- possible adverse effects
All the answers to your CBD questions are here so let’s get started.
If you don’t find an answer in this guide to a question you have, leave us a comment below and we’ll search the published studies to see if an answer exists and get back to you.
Increase CBD Absorption 380%
Learn the exact CBD absorption effects when taking CBD:
- with a high-fat meal
- with a low-fat meal
- with milk
- with alcohol
Published February 3, 2020
Study Results
CBD taken with a high-fat meal
520% increase in peak CBD blood concentration – 380% more effective than when taken orally without food. (1) 
CBD taken with a low-fat meal
270% increase in peak CBD blood concentration – 380% total increased exposure to CBD taken orally (2)
CBD taken with whole milk
240% increase in peak CBD blood concentration – 310% total increased exposure to CBD taken orally (3) 
CBD taken with alcohol
160% increase in peak CBD blood concentration – 190% total increased exposure to CBD taken orally (4) 
Our Summary
CBD absorption rates were tested for a pure oral CBD product containing 750mg of CBD.
Procedure
- 15 healthy adults consumed 750mg pure CBD with a high calorie/high-fat meal
- 14 healthy adults consumed 750mg pure CBD with a low calorie/low-fat meal
- 15 healthy adults consumed 750mg pure CBD with whole milk
- 14 healthy adults consumed 750mg pure CBD with alcohol
- 14 healthy adults consumed 750mg pure CBD after fasting/empty stomach
- Blood samples were collected over a 96 hour period after ingesting the CBD product orally
- Blood samples were evaluated by liquid chromatography and tandem mass spectrometry (5)
Outcomes
CBD taken with food substantially increased the maximum amount of CBD in the blood as well as the total overall exposure of the body to CBD within 96 hours of taking an oral cannabidiol product.
Adverse effects
Cannabidiol side effects were minimal with no severe adverse effects. (6)
Further reading: 2020 medical study shows significant cardiovascular benefits from oral CBD. See the study here.
CBD Dosage and Side Effects
CBD is generally well tolerated with mild side effects:
- know exact side effects possible taking CBD
- know how long it takes for CBD to reach peak concentration in the blood
Published November 3, 2018
Study Findings
- CBD is generally well tolerated.
- no serious or severe adverse effects from taking oral CBD in this study
- CBD side effects were few and mild. (1)
Possible Adverse effects
- diarrhea
- nausea
- headache
- drowsiness (2)
Study Results
- Taking oral CBD twice daily may be recommended given its minimal adverse effects and its diminishing concentration in the blood after a 10-17 hour period.
- Peak CBD concentration in the blood occurred 4-5 hours after taking CBD dose.
- The effective half-life of CBD in the blood was 10-17 hours.
- Taking CBD orally with a high-fat meal significantly increased maximum blood concentrations. (3)
Our Summary
This was a phase 1, randomized, double-blind, placebo-controlled study.
By The Numbers
There were three groups of participants and multiple dosages:
- single increasing dose group: CBD dosage of 1500mg, 3000mg, 4500mg or 6000mg (6 participants and 2 placebo participants per dosage group)
- multiple-dose group (taking CBD dose twice daily): CBD dosage 750mg or 1500mg (9 participants and 3 placebo participants per dosage group)
- oral CBD dose taken with high-fat meal group: CBD dosage 1500mg (12 participants and 0 placebo participants in this dosage group)
- All participants completed the study. (4)
Adverse Effects
- there were no serious adverse effects recorded.
- CBD group had increased instances of diarrhea and headaches compared to the placebo group.
- all adverse effects were mild to moderate.
- there were no “severe or serious” adverse effects. (5)
Video: CBD oil side effects
Keywords: cannabidiol dosage; adverse effects
Turbo CBD vs. Generic CBD
Published November 2019
Study Results
90mg TurboCBD vs. Generic CBD capsule
- TurboCBD had 86% more CBD circulating in the body at 90 minutes
- Turbo CBD had 65% more CBD circulating int the body at 120 minutes (1)
Our Summary
This was a human trial to find out the absorption characteristics for a product called TurboCBD made by Lexaria Bioscience Corp. vs. generic CBD capsules. (2)
Evaluation
- cannabidiol absorption
- distribution
- metabolism
- excretion characteristics
The study was funded by Lexaria Bioscience Corp. (3)
By The Numbers
- 12 participants
- double-blinded
- placebo-controlled
- cross-over design medical study.
Each participant received 45mg or 90mg of generic CBD or TurboCBD capsules on five separate occasions.
45mg CBD capsule
TurboCBD capsules vs 45mg generic CBD capsules
- no difference in circulating CBD at 90 minutes after ingestion
- no difference in circulating CBD at 120 minutes after ingestion (4)
90mg CBD capsule
90mg TurboCBD capsules vs. a generic 90mg CBD capsule
- 86% more CBD circulating at 90 minutes after ingestion
- 65% more CBD circulating 120 minutes after ingestion (5)
After 4 hours
The TurboCBD product also caused an elevated CBD load in the bloodstream 4 hours after taking the capsules vs. a 90mg generic CBD capsule.
Conclusion
The higher cannabidiol bio-availability of the TurboCBD product causes greater absorption of CBD into the bloodstream and higher peak CBD loads. (6)
Keywords: Cannabidiol; Cerebrovascular conductance; Gas chromatography-mass spectrometry; CBD Pharmacokinetics
CBD Dosage Study For Children
Published July 3, 2019
Study Results
7 children with childhood epilepsy had minimal to no adverse effects while taking an oral CBD for epilepsy product at dosages up to 10-12 mg CBD/kg/day. (1)
By The Numbers
- starting dose tested was 5-6 mg CBD/kg/day.
- 1:20 THC to CBD ratio.
Benefit
The children had improvements in seizure frequency and quality of life scores. (2)
Intoxication
Levels of THC remained lower than what would be expected to cause intoxication. (3)
Entourage Effect
The study said the best results occurred when a whole hemp plant product is used. (4)
Our Summary
This is preliminary data from the “Cannabidiol in Children with Refractory Epileptic Encephalopathy (CARE-E)” study.
It is known that CBD helps with childhood epilepsy but cannabinoid dosage needs further investigation for adverse effects and long term use. (5)
The study started the children on a Cannabis plant extract at a dosage of 5-6 mg CBD/kg/day.
The dose was eventually increased to 10-12 mg CBD/kg/day.
The CBD product has a THC:CBD ratio of 1:20. (6)
Analysis
Data were collected for:
- Seizure frequency
- regular electroencephalograms
- Quality of Life in Childhood Epilepsy (QOLCE)
- Side Effects
Unexpected
The study suggests that concentrations of CBD in the blood may increase or decrease unexpectedly and further study is needed. (7)
Intoxication
The study also found that in doses of up to 10-12 mg CBD/kg/day at a THC:CBD ratio of 1:20 the level of THC in the blood remained low enough so that none of the children became intoxicated. (8)
Keywords: cannabidiol; cannabinoid plasma levels; cannabis; epileptic encephalopathy; Δ9-tetrahydrocannabinol
References
Crockett J, Critchley D, Tayo B, Berwaerts J, Morrison G. A phase 1, randomized, pharmacokinetic trial of the effect of different meal compositions, whole milk, and alcohol on cannabidiol exposure and safety in healthy subjects. Epilepsia. 2020;61(2):267–277. doi:10.1111/epi.16419
Study Authors
GW Research Ltd, Cambridge, UK
GW Research Ltd, Cambridge, UK
GW Research Ltd, Cambridge, UK
GW Research Ltd, Cambridge, UK
GW Research Ltd, Cambridge, UK
References
Taylor L, Gidal B, Blakey G, Tayo B, Morrison G. A Phase I, Randomized, Double-Blind, Placebo-Controlled, Single Ascending Dose, Multiple Dose, and Food Effect Trial of the Safety, Tolerability and Pharmacokinetics of Highly Purified Cannabidiol in Healthy Subjects [published correction appears in CNS Drugs. 2019 Apr;33(4):397]. CNS Drugs. 2018;32(11):1053–1067. doi:10.1007/s40263-018-0578-5
Study Authors
GW Research Ltd, Cambridge, UK
University of Wisconsin School of Pharmacy
Consult2deliver Ltd, Nottingham, UK
GW Research Ltd, Cambridge, UK
GW Research Ltd, Cambridge, UK
References
Patrician A, Versic-Bratincevic M, Mijacika T, et al. Examination of a New Delivery Approach for Oral Cannabidiol in Healthy Subjects: A Randomized, Double-Blinded, Placebo-Controlled Pharmacokinetics Study. Adv Ther. 2019;36(11):3196–3210. doi:10.1007/s12325-019-01074-6
Study Authors
Centre for Heart, Lung and Vascular Health, University of British Columbia
Department of Toxicology and Pharmacogenetics, University of Split School of Medicine
Department of Integrative Physiology, University of Split School of Medicine
Department of Integrative Physiology, University of Split School of Medicine
Department of Health Studies, University of Split
Department of Toxicology and Pharmacogenetics, University of Split School of Medicine
Department of Pathology, Forensic Medicine and Citology, University Hospital Centre Split
Department of Integrative Physiology, University of Split School of Medicine
Centre for Heart, Lung and Vascular Health, University of British Columbia
References
Huntsman RJ, Tang-Wai R, Alcorn J, et al. Dosage Related Efficacy and Tolerability of Cannabidiol in Children With Treatment-Resistant Epileptic Encephalopathy: Preliminary Results of the CARE-E Study. Front Neurol. 2019;10:716. Published 2019 Jul 3. doi:10.3389/fneur.2019.00716
Study Authors
Cannabinoid Research Initiative of Saskatchewan, University of Saskatchewan
Department of Pediatrics, Royal University Hospital, University of Saskatchewan
Cannabinoid Research Initiative of Saskatchewan, University of Saskatchewan
Division of Child Neurology, Department of Pediatrics, Loma Linda University
Cannabinoid Research Initiative of Saskatchewan, University of Saskatchewan
College of Pharmacy and Nutrition, University of Saskatchewan
College of Pharmacy and Nutrition, University of Saskatchewan
Cannabinoid Research Initiative of Saskatchewan, University of Saskatchewan
Cannabinoid Research Initiative of Saskatchewan, University of Saskatchewan
Clinical Trial Support Unit, Royal University Hospital, University of Saskatchewan
Cannabinoid Research Initiative of Saskatchewan, University of Saskatchewan
College of Pharmacy and Nutrition, University of Saskatchewan
Cannabinoid Research Initiative of Saskatchewan, University of Saskatchewan
Clinical Trial Support Unit, Royal University Hospital, University of Saskatchewan
Cannabinoid Research Initiative of Saskatchewan, University of Saskatchewan
Cell Signalling Laboratory, Departments of Psychiatry and Physiology, University of Saskatchewan
Department of Pediatrics, Royal University Hospital, University of Saskatchewan
Department of Pediatrics, Royal University Hospital, University of Saskatchewan
Cannabinoid Research Initiative of Saskatchewan, University of Saskatchewan
Department of Pharmaceutical Services, Royal University Hospital, Saskatchewan Health Authority
Cannabinoid Research Initiative of Saskatchewan, University of Saskatchewan
Division of Neurology, Department of Medicine, Royal University Hospital, University of Saskatchewan
Really interesting to see how much taking CBD with a fatty meal changes the effective amount of CBD you get in your system. I would never have guessed taking CBD with a fatty meal would have made like a 500% increase in how much cbd you get. Crazy. Even just taking it with milk makes a big difference. Really cool info.
Thank you for the comment. It’s impressive CBD research. Really changes how you think about taking CBD and cannabinoids.