Is Ceylon or cassia cinnamon better?

Ceylon has far less coumarin, and cassia is cheaper and stronger in flavour. For regular or medicinal use, I would choose Ceylon, or a product that names its species. Cassia in normal cooking amounts is a different matter from a daily spoonful.

How much cassia is too much?

The BfR sets a tolerable daily intake for coumarin of 0.1 mg per kg of body weight. For a 60 kg adult, it estimates that about 2 g of cassia with an average coumarin content a day would reach that limit. Coumarin can affect the liver in a small group of sensitive people, and the effect is usually reversible. The BfR reports it mainly from coumarin used as a medicine.

Does cinnamon lower blood sugar?

The trials disagree. The 2013 meta-analysis found a modest fall in fasting glucose and no clear change in HbA1c, and the Cochrane review found the evidence insufficient. I would not promise a result.

Is cinnamon essential oil safe to swallow?

I would not, unless it is a product designed and tested for that purpose. The EU monograph does not recommend the undiluted oil, and the assessment report regards cinnamon bark oil as a potential skin sensitiser. The oil is a different thing from the bark.

Cinnamon: What It Is, How It Works, and When to Use It

Sarah Burt

16 hours ago

8 min read

Cinnamon is the dried inner bark of tropical trees in the genus Cinnamomum, and it sits in nearly every British kitchen. It also has a long record as a warming digestive herb, and in recent decades it has attracted a great deal of research interest for blood sugar. The trial evidence is mixed. The type of cinnamon on the label matters more than most people realise, because the two main types differ sharply in a compound called coumarin. It is one of the four herbs in the EarthWise Adrenal Guard tonic.

Close-up of piled cinnamon sticks with curled ends, in warm golden-brown light, creating a cozy, aromatic feel.

What it is

Cinnamon belongs to the laurel family (Lauraceae). The trees are evergreens that grow in warm, humid places, and the spice comes from the bark. Harvesters strip the bark from young shoots, peel away the outer layer and dry the inner bark, which curls into the familiar quills.

Two types dominate the market. Ceylon cinnamon (Cinnamomum verum, also called true cinnamon) comes mainly from Sri Lanka. It forms thin, papery, many-layered quills with a mild, sweet flavour. Cassia (Cinnamomum cassia, also sold as C. aromaticum) comes from China and south-east Asia. Its bark is thicker and darker, with a harder, more pungent taste. NCCIH notes that cassia is the most common type sold in North America, and inexpensive ground cinnamon is often cassia or a blend.

A buyer's note worth reading. A label that says only "cinnamon" can mean either type, and it can also mean a product made from other plant parts. The US National Center for Complementary and Integrative Health (NCCIH) makes the same point: many products do not state the species or the part used. Look for the Latin name. For the herb itself, I would want a supplier that names the species, the part (bark) and, ideally, the country of origin.

The active compounds

Cinnamon bark contains up to about 4% essential oil. Most of that oil is cinnamaldehyde, which makes up roughly 60 to 75% and gives cinnamon its smell and taste. The oil also contains eugenol, cinnamyl acetate, linalool and other aromatic compounds. The bark itself holds procyanidins (a group of polyphenols), cinnamic acid, other phenolic acids and mucilage.

Coumarin is the compound that separates the two types. The German Federal Institute for Risk Assessment (BfR) reports that cassia contains about 3 g of coumarin per kilogram on average, and as much as 10 g per kilogram in some samples. Ceylon cinnamon contains only low levels.

The main proposed mechanism. Laboratory work suggests that compounds in cinnamon, including the procyanidins, may affect how cells respond to insulin and how quickly sugars are absorbed. These are cell and animal findings. The EU assessment report found no clinical pharmacology data on Ceylon cinnamon, so how any of this applies to a person drinking a tincture is uncertain.

How it is traditionally used

Cinnamon has a long history in Chinese, Ayurvedic and European herbal practice as a warming herb. In Western herbal practice it is used for the digestion, with a reputation for easing wind, bloating and cold, sluggish digestion. It is also traditionally linked to circulation and warmth in the extremities.

The EU herbal committee (HMPC) adopted a monograph in May 2011 on the essential oil of Ceylon cinnamon bark. It recognises the oil as a traditional herbal medicine for the relief of mild, spasmodic gastrointestinal complaints, including bloating and flatulence, at 50 to 200 mg a day in two to three doses. The monograph does not recommend the undiluted oil, because it irritates. It does not recommend use under 18 years, and it says safety in pregnancy and breastfeeding has not been established. It lists hypersensitivity to the herb or to Peru balsam as a contraindication, and it advises seeing a doctor or qualified practitioner if symptoms last more than two weeks.

That monograph covers the oil and not the bark. The committee's wider assessment report considered both. It concluded that bark and oil could be regarded as traditional herbal medicines, and that there was no major safety concern for the bark under the conditions of the monograph. It also said the toxicity and genotoxicity data were not sufficient to support a list entry. I have read the monograph and the draft assessment report, and I have not confirmed whether the committee has published anything newer.

The idea of cinnamon as a blood sugar herb is more recent. It comes from the research of the past twenty years and not from traditional use, and it is the reason cinnamon appears in Adrenal Guard alongside Holy Basil, Siberian Ginseng and Gymnema.

What the research shows

Here is how the evidence reads.

Traditional evidence: digestive comfort. This is the basis of the EU monograph. It is a legitimate foundation for a warming kitchen herb, and it is a weaker one than a well-run trial.

Evidence: blood sugar. A 2013 meta-analysis in the Annals of Family Medicine (Allen and colleagues) pooled 10 randomised trials with 543 people who had type 2 diabetes. Cinnamon lowered fasting blood glucose by about 25 mg/dL on average (a range of roughly 9 to 41 mg/dL). It did not produce a significant change in HbA1c, the longer-term marker (about 0.16 percentage points lower, with a range that crossed zero). The trials disagreed strongly with each other (I² of 66% to 95%), the authors suspected publication bias for the glucose result.

A mismatch worth knowing. Most trials used cassia, in capsules or powder, at doses of grams a day. The EU assessment report points out that those studies were not on Ceylon cinnamon. A 1:3 tincture in a multi-herb tonic is a different thing, and I cannot compare it with those doses.

Safety evidence. Cinnamon in food amounts is regarded as safe. The questions are coumarin in cassia, the skin and mouth irritation from cinnamon oil, and a lack of data in pregnancy.

Sarah's clinical perspective

I use cinnamon in Adrenal Guard as a tincture, alongside Holy Basil, Siberian Ginseng and Gymnema. In traditional use it is a warming herb for the digestion and circulation, and I include it as one of the two herbs in the formula that people turn to when blood sugar swings are part of the picture.

I ask anyone taking medication for diabetes, blood sugar or blood pressure to check with their GP or practitioner before using Adrenal Guard, because cinnamon and Gymnema may influence glucose levels. I do not recommend the formula in pregnancy or breastfeeding, and I ask anyone on stimulant medication or immunosuppressant medication to take advice first.

Practical guidance

Dose. The EU monograph gives 50 to 200 mg of the essential oil a day in two to three doses, and it does not recommend the undiluted oil. There is no EU figure for the bark itself. Trial doses ranged from 120 mg to 6 g a day of powder or capsules, and I would not use them as a guide for any tincture. These are not dosing instructions for any particular product, including Adrenal Guard.

Format. Ground or quill bark in food, a tea or decoction of the bark, a tincture, or a capsule. Cinnamon essential oil is a separate product with different risks, and I explain why in the questions below.

Time to effect. There is no clinical timeline. The EU monograph advises seeing a doctor or practitioner if digestive symptoms last more than two weeks.

Timing. There is no established timing. For digestion it is traditionally taken with or after meals.

What it does not replace. Cinnamon does not replace medical assessment or diabetes care. Persistent thirst, passing a lot of urine, unexplained weight loss, ongoing digestive symptoms or very low or very high glucose readings need a GP.

For how to take the EarthWise tonic specifically, the dose and full safety information are on the product page.

Common questions

Is Ceylon or cassia cinnamon better? Ceylon has far less coumarin, and cassia is cheaper and stronger in flavour. For regular or medicinal use, I would choose Ceylon, or a product that names its species. Cassia in normal cooking amounts is a different matter from a daily spoonful.
How much cassia is too much? The BfR sets a tolerable daily intake for coumarin of 0.1 mg per kg of body weight. For a 60 kg adult, it estimates that about 2 g of cassia with an average coumarin content a day would reach that limit. Coumarin can affect the liver in a small group of sensitive people, and the effect is usually reversible. The BfR reports it mainly from coumarin used as a medicine.
Does cinnamon lower blood sugar? The trials disagree. The 2013 meta-analysis found a modest fall in fasting glucose and no clear change in HbA1c, and the Cochrane review found the evidence insufficient. I would not promise a result.
Can I take cinnamon with diabetes medication? Please speak to your GP or pharmacist first. The EarthWise guidance asks anyone taking medication for diabetes, blood sugar or blood pressure to check before using Adrenal Guard, since cinnamon may influence glucose levels.
Is cinnamon essential oil safe to swallow? I would not, unless it is a product designed and tested for that purpose. The EU monograph does not recommend the undiluted oil, and the assessment report regards cinnamon bark oil as a potential skin sensitiser. The oil is a different thing from the bark.
Is cinnamon safe in pregnancy? NCCIH notes that some studies suggest food amounts are safe. The EU monograph says safety in pregnancy and breastfeeding has not been established, and the EarthWise guidance advises against Adrenal Guard in pregnancy and breastfeeding.

Where cinnamon appears in the EarthWise range

Cinnamon is one of the four herbs in Adrenal Guard, Sarah's formula for energy and steady blood sugar, where it sits with Holy Basil, Siberian Ginseng and Gymnema.

If you are not sure which formula fits, the EarthWise health quiz is the best place to start. Full safety information is on each product page.

When to seek professional support

Cinnamon in food amounts is well tolerated, and the main reasons for care are blood sugar medication, coumarin and the oil. Check with a practitioner first in these situations:

Diabetes, or medication for blood sugar or blood pressure. Cinnamon may influence glucose levels, so check with your GP or pharmacist.
Liver disease, or regular use of large amounts of cassia. NCCIH notes that prolonged use of cassia could be an issue for sensitive people, including those with liver disease.
Allergy to cinnamon or Peru balsam. The EU monograph lists this as a contraindication.
Cinnamon oil. It irritates the mouth and skin, and the undiluted oil is not recommended.
Pregnancy and breastfeeding. The EU monograph says safety has not been established.
Digestive symptoms that last more than two weeks. The monograph advises seeing a doctor or qualified practitioner.
Under 18. The monograph does not recommend use in children and adolescents.
Avoiding alcohol. Adrenal Guard contains about 25% ethanol.

Sarah Burt is a registered naturopath, medical herbalist and iridologist with 25+ years of clinical experience. All EarthWise tonics are formulated by Sarah based on her clinical protocols.

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This article is for informational purposes only and is not intended to diagnose, treat or cure any health condition. Always consult a qualified health practitioner before making changes to your health regimen.