The difference between sodium cocoyl glutamate and disodium cocoyl glutamate
| Sodium Cocoyl Glutamate | Disodium Cocoyl Glutamate | |
| Chemical constitution | Sodium monosalt | Disodium salt |
| pH value | Slightly acidic (about 5.0-6.5) | Weakly alkaline (about 7.0-8.5) |
| Mild | Very mild and gentle on the skin | Mild, but slightly weaker than sodium cocoyl glutamate |
| Cleanliness | Mild, relatively weak foaming power | Stronger cleaning and foaming power |
| Texture | Smooth and non-dry after washing | You may feel a slight dryness or "rubbing" after washing |
| Main applications | Personal care products that focus on gentle cleansing | Face Cleansing Mousse, shower gels, shampoos |
Detailed Explanation:
1. Chemical Structure Differences: Both components derive from glutamic acid and coconut oil acid.
Sodium Cocoyl Glutamate: In this compound, one carboxyl group (-COOH) of glutamic acid is neutralized into sodium salt (-COONa), while the other carboxyl group remains in its free acid form. This results in a monosodium salt.
Disodium Cocoyl Glutamate: Both carboxyl groups of glutamic acid are completely neutralized into sodium salts. Therefore, it is a disodium salt.
This slight structural difference directly leads to their different acidity and alkalinity.
2. Relationship between pH value and mildness
This is the most important difference between the two, also the most important factor to consider when selecting a formula
Sodium Cocoyl Glutamate (Weakly Acidic)
Its pH level (approximately 5.5) closely matches the natural pH range of healthy skin (4.5-6.5).
This "weakly acidic" nature means it is very skin-friendly and does not damage the skin's natural acidic protective film (sebum film) when cleaning.
Therefore, it is considered to be an extremely mild surfactant, which is very suitable for sensitive, dry, damaged skin and babies.
Disodium Cocoyl Glutamate (Weakly Alkaline)
It has a pH value slightly above 7, making it weakly alkaline.
Although it is still a much milder amino acid surfactant than soap-based (strongly alkaline), its weak alkalinity has a certain impact on the natural acid-base environment of the skin, and long-term use or for sensitive skin may be more likely to cause dryness or discomfort than monosodium salt.
3. Cleanliness and Texture
Cleanliness: Disodium Cocoyl Glutamate is more neutralized, more soluble and more ionized in water, so it is usually more effective at cleaning and foaming than sodium cocoyl glutamate.
Texture:
Sodium Cocoyl Glutamate: After washing, the feeling is usually moist and smooth, without a tight feeling.
Disodium Cocoyl Glutamate: Some people may feel a slight dryness similar to that of a soap-based cleanser, but much less severe.
4. Applications in formulations
Sodium Cocoyl Glutamate: With its excellent mildness, it is often used as the main active ingredient. It is often found in high-end facial cleansers that are clearly labeled as "mild", "suitable for sensitive skin", and "weakly acidic".
Disodium Cocoyl Glutamate: Usually used as a primary surfactant, it is more frequently combined with other surfactants (e.g., betaines) to enhance foaming and cleaning power while maintaining the formula's gentleness. It is commonly found in shower gels, shampoos, and some facial cleansers.
How to select and summarize?
If you have extremely sensitive or dry skin, or are seeking a cleanser that closely matches your skin's natural pH:
Please prioritize products with sodium cocoyl glutamate as the primary surfactant. It is a purer and more refined "gentle" option.
If you have oily or combination skin, or like to feel cleaner after cleansing but don't want to use irritating soap:
Products containing 'Disodium Cocoyl Glutamate' are perfectly safe and a common choice. It delivers stronger cleansing power while maintaining the gentle properties of amino acid surfactant.
In summary, sodium cocoyl glutamate is slightly superior in gentleness and skin affinity, making it a superior choice for gentle cleansing. Disodium cocoyl glutamate, however, has the advantage of cleaning power and practicality, and is a very mainstream and excellent amino acid surfactant on the market.