Summary of Cinnamon
Primary Information, Benefits, Effects, and Important Facts
Cinnamon is popular spice worldwide. It exerts numerous biological effects on the body.
Cinnamon is frequently treated as an anti-diabetic compound, since it reduces the rate at which glucose enters the body. Not only does it help diabetics avoid blood sugar spikes, but it also improves glucose use in the cell itself.
Over time, cinnamon can reduce fasting blood glucose, and potentially cholesterol levels as well.
Cinnamon does not need to be purchased specifically as a supplement, and can be found in grocery stores. It does contain a liver toxin called coumarin, which can be harmful in high doses. Making cinnamon tea can reduce the risk of coumarin poisoning, since the toxin is left behind in the leftover sediment. Ceylon cinnamon, which is dervied from a different plant species, has lower levels of coumarin, which makes it a better supplement option.
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Things To Know & Note
Cinnamon is non-stimulatory
How to Take Cinnamon
Recommended dosage, active amounts, other details
The standard dose for anti-diabetic purposes is 1-6g of cinnamon daily, taken with carbohydrate containing meals.
Ceylon cinnamon is always a better supplemental option than cassia cinnamon, due to the lower coumarin content.
Frequently Asked Questions about Cinnamon
Scientific Research on Cinnamon
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Cinnamon is a spice that contains several bioactive agents. Cinnamaldehydes give cinnamon its aroma, Coumarins (a toxin) contribute to taste  , and several compounds including MethylHydroxyChalcone polymers (MHCPs) contribute to its systemic insulin sensitizing benefits. Beyond the three unique compounds listed, cinnamon also contains tannins, flavonoids, glycosides, terpenoids and anthraquinones. 
Cinnamon exerts beneficial control effects against pro-diabetic diets in a number of ways.
Cinnamon can inhibit numerous digestive enzymes, such as alpha-glucosidase  , sucrase  and potentially pancreatic amylase (although the only results were confounded with acarbose).  Via inhibition of these enzymes, cinnamon can decrease the influx of glucose into systemic circulation and avoid overly significant insulin spikes.
In systemic circulation (beyond the liver) cinnamon also possesses anti-diabetic effects. A compound in cinnamon, methylhydroxychalcone polymer (MHCP), acts as an insulin mimetic on adipocytes.  MHCP's effects as an insulin mimetic are dose dependent, and act by transphosphorlyating the insulin receptor on the cytoplasmic membrance (the same mechanism as the insulin molecule itself). Its effects on glucose uptake and glycogen, however dose-dependent, seem to be time-delayed (When insulin acts within 10 minutes of reaching the cell, MHCPs take 30-60, suggesting an intra-cellular time delay).
Cinnamon has also been implicating in aiding insulin function, potentiating its effects more than 20-fold in vitro. 
When ingested in human trials, cinnamon shows much promise in reducing blood glucose levels    and sometimes markers of lipid metabolism (LDL, Triglycerides, Total cholesterol).  There are also intervention studies noting improved insulin sensitivity with cinnamon extract, possibly vicariously through the reduced blood glucose levels.  
Coumarin is a hepatotoxic and carcinogenic phytochemical found in some plants that is present at high levels in certain variants of cinnamon. Coumarin is not the active compound that reduces blood sugar, but one that exists alongside the active ingredient(s). It initially had a TDI (Tolerable Daily Intake) of 2mg/kg bodyweight max, but was lowered to 0.5 and currently stands at 0.1mg/kg bodyweight.  Although a safety buffer is included in this last recommendation, some subsets of the human population are more sensitive to coumarin toxicity due to a reduced capacity to metabolize it. 
This is relevant since most of the anti-diabetic benefits with cinnamon come in a dose dependent manner, in the range of 300mg/kg bodyweight  . At these doses, coumarin above the TDI can easily be ingested.
The best method of coumarin avoidance is to choose the right source of cinnamon. Ceylon cinnamon has the lowest levels of coumarin with below 190 mg/kg (some samples being below detection levels) whereas Cassia contains between 700 mg/kg on the low-end to as much as 12,230 mg/kg on the high-end.. Ceylon can be detected in stick form via its numerous thin folds, whereas Cassia has less folds and a thicker appearance. They cannot be distinguished in powder form, and Cassia is more frequently used in production and manufacturing due to its general high availability and low cost.  
Via the above numbers, a 200lb human can ingest 47.8g of Ceylon Cinnamon and arrive at the 0.1mg/kg bodyweight TDI for coumarin at worst (using the highest recorded dose of coumarin in cinnamon). on the other hand, using Cassia cinnamon can easily place somebody above the TDI for coumarin with a far lesser intake.
Coumarin absorption does not seem to be dependent on the form of cinnamon ingested. Similar serum levels and excreted levels were achieved with isolated coumarin, pill form cinnamon, tea and rice pudding (solid food).  These results were standardized to X dose of coumarin, so the source of cinnamon is irrelevant.
The above study, however, did note a 38.5% extraction rate of coumarin from powder to liquid when steeped (just boiling for 30 minutes); suggesting that one can tip the scales more in favor of water-soluble polyphenols and MHCPs relative to coumarins if steeped and served in tea or using said cinnamon water to mix protein shakes with, as the water-soluble components have a much higher extraction rate.
- Characterization of antioxidant and antimicrobial compounds of cinnamon and ginger essential oils.
- Abraham K, et al. Toxicology and risk assessment of coumarin: focus on human data. Mol Nutr Food Res. (2010)
- A Hydroxychalcone Derived from Cinnamon Functions as a Mimetic for Insulin in 3T3-L1 Adipocytes.
- Mohamed Sham Shihabudeen H, Hansi Priscilla D, Thirumurugan K. Cinnamon extract inhibits α-glucosidase activity and dampens postprandial glucose excursion in diabetic rats. Nutr Metab (Lond). (2011)
- Adisakwattana S, et al. Inhibitory activity of cinnamon bark species and their combination effect with acarbose against intestinal α-glucosidase and pancreatic α-amylase. Plant Foods Hum Nutr. (2011)
- Isolation and Characterization of Chalcone Polymers from Cinnamon with Insulin-Like Biological Activity.
- Imparl-Radosevich J, et al. Regulation of PTP-1 and insulin receptor kinase by fractions from cinnamon: implications for cinnamon regulation of insulin signalling. Horm Res. (1998)
- Broadhurst CL, Polansky MM, Anderson RA. Insulin-like biological activity of culinary and medicinal plant aqueous extracts in vitro. J Agric Food Chem. (2000)
- Kirkham S, et al. The potential of cinnamon to reduce blood glucose levels in patients with type 2 diabetes and insulin resistance. Diabetes Obes Metab. (2009)
- Pham AQ, Kourlas H, Pham DQ. Cinnamon supplementation in patients with type 2 diabetes mellitus. Pharmacotherapy. (2007)
- Mang B, et al. Effects of a cinnamon extract on plasma glucose, HbA, and serum lipids in diabetes mellitus type 2. Eur J Clin Invest. (2006)
- Khan A, et al. Cinnamon improves glucose and lipids of people with type 2 diabetes. Diabetes Care. (2003)
- Anderson RA. Chromium and polyphenols from cinnamon improve insulin sensitivity. Proc Nutr Soc. (2008)
- Qin B, Panickar KS, Anderson RA. Cinnamon: potential role in the prevention of insulin resistance, metabolic syndrome, and type 2 diabetes. J Diabetes Sci Technol. (2010)
- Solvent-assisted supercritical fluid extraction for the isolation of semivolatile flavor compounds from the cinnamons of commerce and their separation by series-coupled column gas chromatography.
- Woehrlin F, et al. Quantification of flavoring constituents in cinnamon: high variation of coumarin in cassia bark from the German retail market and in authentic samples from indonesia. J Agric Food Chem. (2010)
- Abraham K, et al. Relative bioavailability of coumarin from cinnamon and cinnamon-containing foods compared to isolated coumarin: a four-way crossover study in human volunteers. Mol Nutr Food Res. (2011)
- Yisahak SF, et al. Diabetes in North America and the Caribbean: an update. Diabetes Res Clin Pract. (2014)
- Baker I, Chohan M, Opara EI. Impact of cooking and digestion, in vitro, on the antioxidant capacity and anti-inflammatory activity of cinnamon, clove and nutmeg. Plant Foods Hum Nutr. (2013)
- Nabavi SF, et al. Antibacterial Effects of Cinnamon: From Farm to Food, Cosmetic and Pharmaceutical Industries. Nutrients. (2015)
- Crawford P. Effectiveness of cinnamon for lowering hemoglobin A1C in patients with type 2 diabetes: a randomized, controlled trial. J Am Board Fam Med. (2009)
- Blevins SM, et al. Effect of cinnamon on glucose and lipid levels in non insulin-dependent type 2 diabetes. Diabetes Care. (2007)
- Esterbauer H, Schaur RJ, Zollner H. Chemistry and biochemistry of 4-hydroxynonenal, malonaldehyde and related aldehydes. Free Radic Biol Med. (1991)
- McGowan MP, Proulx S. Nutritional supplements and serum lipids: does anything work?. Curr Atheroscler Rep. (2009)
- Magistrelli A, Chezem JC. Effect of ground cinnamon on postprandial blood glucose concentration in normal-weight and obese adults. J Acad Nutr Diet. (2012)
- Frijhoff J, et al. Clinical Relevance of Biomarkers of Oxidative Stress. Antioxid Redox Signal. (2015)
- Luft VC, et al. Carboxymethyl lysine, an advanced glycation end product, and incident diabetes: a case-cohort analysis of the ARIC Study. Diabet Med. (2016)