Cinnamon Bark Extract
Updated September 17, 2026 · By Theo Marchetti
The Short Answer
Cinnamon bark extract is a widely available botanical with dose-response evidence for modest fasting blood glucose and HbA1c reduction. Meta-analyses of randomized trials show the clearest benefit at doses above 1,500 mg per day, though concentrated extracts have shown effects as low as 120 mg/day. Both Cassia and Ceylon species contain the active polyphenols, but Cassia carries coumarin-related safety considerations at high chronic doses. Look for supplements disclosing the cinnamon species and standardization method.
What is Cinnamon Bark Extract?
Cinnamon bark extract is a concentrated form of the spice derived from the inner bark of Cinnamomum trees — primarily Cassia cinnamon (C. cassia, also called Chinese cinnamon) and Ceylon cinnamon (C. verum, sometimes labeled 'true cinnamon'). Both species contain bioactive compounds including cinnamaldehyde, cinnamic acid, and Type-A procyanidins. The extract form concentrates these compounds beyond what culinary cinnamon powder delivers per gram, making it a common ingredient in blood sugar and metabolism support supplements.
How it works
Cinnamon's metabolic effects are attributed primarily to its polyphenol content, which may improve insulin sensitivity through several pathways. In vitro studies suggest cinnamon polyphenols enhance insulin receptor phosphorylation and glucose transporter translocation, increasing cellular glucose uptake. Cinnamaldehyde may also activate AMPK and peroxisome proliferator-activated receptors (PPARs), enzymes involved in lipid and glucose metabolism. Additionally, cinnamon may slow gastric emptying, which can blunt postprandial blood sugar spikes.
What the evidence says
Cinnamon bark has been evaluated in multiple randomized controlled trials and several systematic reviews for its effects on fasting blood glucose, HbA1c, and insulin resistance. The evidence is generally positive but heterogeneous — study quality, cinnamon species, extract standardization, and dose all vary widely across trials.
- Dose-response meta-analysis confirmed cinnamon supplementation significantly reduces fasting blood glucose and HbA1c, with stronger effects at doses above 1,500 mg/day. — A 2023 updated systematic review and dose-response meta-analysis of randomized controlled trials in patients with type 2 diabetes. The analysis included 24 RCTs and found statistically significant reductions in fasting blood glucose, HOMA-IR, and HbA1c, with subgroup analyses favoring higher doses and shorter intervention periods. (Jamali et al. (2023), Complementary Therapies in Medicine)
- Meta-analysis of 10 RCTs found cinnamon intake modestly but significantly reduced fasting blood glucose concentrations. — A systematic review and meta-analysis evaluating cinnamon's glycemic effects from 10 randomized controlled trials. Pooled analysis showed a statistically significant reduction in fasting blood glucose. The authors noted high heterogeneity across included studies. (Davis & Yokoyama (2011), Journal of Medicinal Food)
- Cinnamon extract (120 and 360 mg/day) improved fasting blood glucose and glycosylated hemoglobin in Chinese T2DM patients. — A randomized, double-blind, placebo-controlled trial in 66 Chinese patients with type 2 diabetes. Participants received cinnamon extract at 120 mg/day (low dose) or 360 mg/day (high dose) for 3 months. Both cinnamon groups showed significant improvements in fasting blood glucose and HbA1c compared to placebo. (Lu et al. (2012), Nutrition Research)
Effective dosage
Clinical trials have used a wide range of doses, from 120 mg/day (as a concentrated extract) to 6,000 mg/day (as whole cinnamon powder). A 2023 dose-response meta-analysis of randomized controlled trials found that subgroup analyses favored doses above 1,500 mg/day for statistically significant fasting blood glucose and HbA1c reduction. Even the lowest-dose studies that showed benefit used at least 120 mg/day of standardized extract.
Supplements delivering 28 mg or less per serving fall below the minimum dose range with published clinical support. As with all extracts, the standardization method matters — an extract concentrated for cinnamaldehyde or procyanidins may be more potent per milligram than raw powder.
Safety and interactions
Cinnamon bark extract is generally recognized as safe at supplemental doses. The primary safety concern is coumarin content, particularly in Cassia cinnamon — coumarin is a hepatotoxin at high chronic intake. The European Food Safety Authority has set a tolerable daily intake of 0.1 mg coumarin per kg of body weight. Ceylon cinnamon contains negligible coumarin and is preferred for long-term supplementation at higher doses.
Cinnamon may lower blood sugar, so individuals taking diabetes medications should monitor for additive hypoglycemic effects. Consult a healthcare provider before combining cinnamon supplements with glucose-lowering drugs.
Frequently Asked Questions
What is the difference between Cassia and Ceylon cinnamon in supplements?
Cassia cinnamon (Cinnamomum cassia) is the most common and least expensive variety, with higher coumarin content that may stress the liver at chronically high doses. Ceylon cinnamon (Cinnamomum verum) contains negligible coumarin and is considered safer for long-term supplementation, though it is more expensive. Both species contain the bioactive compounds studied for glycemic support. If a supplement label says 'cinnamon bark extract' without specifying the species, it is most likely Cassia.
How much cinnamon bark extract do I need per day for blood sugar support?
Published clinical trials have used 120 to 6,000 mg per day, with meta-analyses suggesting stronger effects above 1,500 mg/day. A concentrated standardized extract may deliver more bioactives per milligram than raw cinnamon powder, but most positive trial results come from doses of at least 120 mg/day of extract or 1,000 mg/day of powder.
Can I get the same benefits from culinary cinnamon?
Possibly, but the dose matters. One teaspoon of ground cinnamon is approximately 2,600 mg. Clinical trials using whole cinnamon powder at 1,000–6,000 mg/day did show glycemic benefits, so a half teaspoon to a teaspoon daily falls within the studied range. However, chronic high intake of Cassia cinnamon raises coumarin exposure concerns. Standardized extracts provide a more controlled dose of the bioactive compounds.