Ingredient review
Ethanolamine Dithiodiglycolate
INCI: ETHANOLAMINE DITHIODIGLYCOLATE
A potent reducing agent for hair restructuring, but requires careful formulation and professional handling to minimize scalp irritation.
In plain English
This ingredient is a chemical that breaks disulfide bonds in hair, allowing it to be reshaped into a straighter or curlier form. It works similarly to ammonium thioglycolate but is often used in 'no-lye' relaxers. Because it can be irritating, it's typically used in salon treatments rather than everyday home products.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Main practical flags: irritation is moderate; clogging risk is low.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- moderate
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Ethanolamine Dithiodiglycolate can be useful, but watch for some irritation potential.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Ethanolamine Dithiodiglycolate.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
moderateCan bother some users, especially with frequent use, damaged skin, or strong companion ingredients.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
Ethanolamine Dithiodiglycolate is a synthetic salt formed from ethanolamine and dithiodiglycolic acid. It acts as a reducing agent in hair care, specifically targeting the disulfide bonds in keratin to permanently alter hair shape.
How it works
When applied to hair, it reduces (breaks) the disulfide bonds between cysteine amino acids in the hair protein. This softens the hair, allowing it to be mechanically straightened or curled. After reshaping, an oxidizing agent (neutralizer) reforms new disulfide bonds to lock the new shape in place.
Pros
Effective hair restructuring
Permanently alters hair shape for straightening or curling, lasting until new hair grows in.
Lower alkalinity than lye
Often formulated at a lower pH than sodium hydroxide relaxers, which may reduce scalp irritation for some users.
Cons and cautions
Irritation risk
Can cause scalp burns, redness, and discomfort if not applied correctly or left on too long.
Requires professional application
Not recommended for home use due to the need for precise timing and neutralization to avoid hair damage.
Best for
- Individuals seeking professional salon hair straightening or perms
- People with healthy, strong hair who want a long-lasting shape change
Use caution if
- Those with sensitive scalp, eczema, or psoriasis
- Anyone with severely damaged, over-processed, or brittle hair
Usage tips
Safety summary
Ethanolamine Dithiodiglycolate is considered safe for professional use when formulated correctly and applied by trained stylists. The main risks are scalp irritation and hair damage from overprocessing. Avoid contact with eyes and broken skin.
Research notes
Studies confirm its efficacy as a reducing agent for hair restructuring. Safety data focus on irritation potential, with moderate evidence supporting its use as an alternative to thioglycolates in relaxers. More long-term scalp health studies are needed.
Common label clues
- Typical concentration
- 1–10% in professional-use products
- Regulatory status
- Approved for use in cosmetics in the EU and US, but concentration limits and labeling requirements apply. Professional use only in many jurisdictions.
- Common uses
- Hair relaxers, Permanent wave solutions
- Environmental note
- Synthetic ingredient; disposal of rinse water should follow local wastewater guidelines. Not known to be bioaccumulative.
Good to know
- This ingredient is often found in 'no-mix' or 'no-lye' relaxer kits, but it still requires careful handling.
- Hair treated with this ingredient should avoid additional chemical services (color, bleach) for at least two weeks.
Common questions
What is Ethanolamine Dithiodiglycolate in beauty products?
This ingredient is a chemical that breaks disulfide bonds in hair, allowing it to be reshaped into a straighter or curlier form. It works similarly to ammonium thioglycolate but is often used in 'no-lye' relaxers. Because it can be irritating, it's typically used in salon treatments rather than everyday home products.
What does Ethanolamine Dithiodiglycolate do in a beauty product?
When applied to hair, it reduces (breaks) the disulfide bonds between cysteine amino acids in the hair protein. This softens the hair, allowing it to be mechanically straightened or curled. After reshaping, an oxidizing agent (neutralizer) reforms new disulfide bonds to lock the new shape in place.
Is Ethanolamine Dithiodiglycolate safe for most people?
Ethanolamine Dithiodiglycolate is considered safe for professional use when formulated correctly and applied by trained stylists. The main risks are scalp irritation and hair damage from overprocessing. Avoid contact with eyes and broken skin.
Who should be careful with Ethanolamine Dithiodiglycolate?
Those with sensitive scalp, eczema, or psoriasis Anyone with severely damaged, over-processed, or brittle hair
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.