What are the three types of curcumin?

January 12, 2026 •

2 min read

Curcuminoids make up 2-9% of the dry weight of turmeric root, with curcumin being the most abundant. These compounds are responsible for the vibrant yellow color and many of the health benefits associated with the spice, including its powerful antioxidant properties.

Quick Summary

The three types of curcuminoids found in turmeric are curcumin, demethoxycurcumin, and bisdemethoxycurcumin. They differ structurally by the number of methoxy groups, which impacts their potency, stability, and bioavailability. The primary curcuminoid is curcumin, but the minor components contribute to the spice's overall health benefits.

Key Points

Three primary types: The three main curcuminoids are curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC).
Structural differences: Each type is distinguished by the number of methoxy groups: two in curcumin, one in DMC, and none in BDMC.
Varying potency: Curcumin is the most potent antioxidant, followed by demethoxycurcumin, with bisdemethoxycurcumin being the least potent.
Different stability: Curcumin is less stable in alkaline conditions compared to DMC and BDMC.
Improved bioavailability: Due to their structural differences, DMC and BDMC may have higher bioavailability than pure curcumin.
Synergistic effect: The health benefits of turmeric come from the combined, synergistic action of all three curcuminoids.
Supplement standardization: Commercial curcumin supplements are typically a mixture of all three, standardized to at least 95% total curcuminoids.
Low absorption challenge: All curcuminoids have low inherent bioavailability, which is why supplements often include absorption enhancers like piperine.

The Three Principal Curcuminoids

The structure of each curcuminoid is differentiated by the presence of methoxy groups. Curcumin has two, demethoxycurcumin has one, and bisdemethoxycurcumin has none. This structural variation affects their properties and biological activity.

Curcumin (Curcumin I)

Curcumin is the most common curcuminoid, making up about 77% of the total. With two methoxy groups, it has the highest antioxidant capacity and is stable in neutral and acidic conditions. Curcumin is known for its anti-inflammatory and antioxidant effects, but its absorption is generally poor. Most supplements are a mix of all three curcuminoids, typically standardized to 95% total.

Demethoxycurcumin (Curcumin II)

Demethoxycurcumin makes up around 17% of the curcuminoids. Having one methoxy group, its potency is slightly less than curcumin's. However, it may be more stable in alkaline conditions than pure curcumin and contributes to the overall effects of turmeric extract.

Bisdemethoxycurcumin (Curcumin III)

Bisdemethoxycurcumin is the least abundant (3-6%) and lacks methoxy groups. It has the lowest antioxidant potency but the highest stability in alkaline conditions. All three curcuminoids have shown anti-inflammatory and anti-proliferative effects, suggesting turmeric's benefits come from their combined action.

Comparing the Three Curcuminoids

Here’s a comparison of the three curcuminoids based on their properties:


Feature	Curcumin (Curcumin I)	Demethoxycurcumin (Curcumin II)	Bisdemethoxycurcumin (Curcumin III)
Methoxy Groups	Two (-OCH3)	One (-OCH3)	None
Proportion in Turmeric	~77%	~17%	3-6%
Relative Antioxidant Potency	Highest	Moderate	Lowest
Stability (in alkaline pH)	Low (Degrades faster)	Moderate (More stable)	Highest (Most stable)
Pharmacological Activity	Strong anti-inflammatory and antioxidant	Significant anti-inflammatory and antioxidant	Lower potency, but contributes synergistically
Bioavailability	Low (limiting factor)	Higher (relative to curcumin)	Highest (relative to curcumin and DMC)

Beyond the Three: Curcuminoid Bioavailability

A major hurdle for curcuminoid use is their low bioavailability, meaning poor absorption by the body. Supplements often add ingredients like piperine from black pepper to boost absorption. Bisdemethoxycurcumin may have better bioavailability than curcumin. Researchers are developing new delivery methods to improve absorption.

Conclusion

Curcumin is a term for three active molecules: curcumin, demethoxycurcumin, and bisdemethoxycurcumin. While curcumin is the most potent antioxidant, its stability and absorption are limited. DMC and BDMC have different properties, including potentially better stability and bioavailability, adding to turmeric's benefits. Using whole turmeric or a full-spectrum extract may provide the most comprehensive health advantages due to the synergistic effects of all three curcuminoids.

This article is for informational purposes only and should not be considered medical advice. Always consult a healthcare professional before taking supplements.

Frequently Asked Questions

Curcumin is the primary and most abundant active compound in turmeric. 'Curcuminoids' is the collective term for the three main related compounds found in turmeric: curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC).

Curcumin (Curcumin I) is generally considered the most potent of the three curcuminoids in terms of antioxidant activity. However, some research suggests that the combined effects of all three curcuminoids, as found in a full-spectrum extract, may be more beneficial due to their synergistic action.

Yes, research indicates that curcumin, demethoxycurcumin, and bisdemethoxycurcumin all exhibit anti-inflammatory properties, though with varying degrees of potency. Their collective effect contributes significantly to turmeric's anti-inflammatory reputation.

Curcumin has poor bioavailability, meaning it is not easily absorbed by the body, rapidly metabolized, and quickly eliminated. Its poor water solubility is a major contributing factor. This is why many supplements use bioavailability-enhancing formulations.

Many curcumin supplements add an absorption enhancer, such as piperine from black pepper, to increase bioavailability. Other modern formulations use advanced delivery systems like liposomes, nanoparticles, or micelles to improve absorption.

Yes, by consuming turmeric root or powder, you are getting all three natural curcuminoids. However, the total concentration of these compounds in raw turmeric is relatively low, and their bioavailability is poor without a proper absorption method.

A full-spectrum curcuminoid extract contains curcumin, demethoxycurcumin, and bisdemethoxycurcumin, offering the synergistic benefits of all three compounds. Some research suggests that the minor curcuminoids offer distinct advantages, including potentially higher stability and bioavailability, making a full extract a potentially more comprehensive option.