What Is Propylenediammonium Dimaleate?
Propylenediammonium Dimaleate is an organic salt formed when propylene diamine reacts with maleic acid, creating a water-soluble compound that works well with hair fibers. It entered the beauty world in the mid-2010s after chemists discovered it could help rebuild bonds inside damaged hair, making it popular in professional salon treatments. Production usually involves neutralizing maleic acid with propylene diamine under controlled pH and temperature, then purifying the resulting crystals before drying them into a fine powder. You will most often spot this ingredient in bond-repair masks, deep conditioners, leave-in treatments and color-protecting products that aim to strengthen and smooth hair without weighing it down.
Propylenediammonium Dimaleate’s Cosmetic Benefits/Uses
Its main role in a formula is hair conditioning, meaning it helps improve the feel, strength and overall appearance of hair. By supporting the internal structure of each strand it can reduce breakage, boost shine and leave hair softer and easier to manage after chemical services or daily styling stress.
Who Can Use Propylenediammonium Dimaleate
This bond-building salt is generally considered suitable for all hair and scalp types including oily, dry, damaged and color-treated strands because it is water soluble and lightweight. It does not clog follicles or leave heavy residues so even people with fine hair usually tolerate it well. Those with very sensitive or broken skin on the scalp should still proceed carefully since any active repair ingredient could sting on open cuts.
The compound is synthesized entirely from petrochemical and plant-derived feedstocks without animal-derived inputs or animal testing, making it acceptable for both vegans and vegetarians when sourced from cruelty-free brands.
Current safety data do not flag specific risks for pregnant or breastfeeding women when using rinse-off or leave-in products that contain Propylenediammonium Dimaleate at cosmetic levels. That said this is not medical advice and anyone who is expecting or nursing should review new products with a qualified healthcare provider to be extra safe.
The ingredient does not increase photosensitivity so users do not need to alter their sun protection routine because of it.
Potential Side Effects/Adverse Reactions
Responses to topical Propylenediammonium Dimaleate differ from person to person. The points below outline potential side effects that have been observed or theoretically discussed, yet most consumers will not experience them when the ingredient is used correctly in a finished product.
- Mild scalp redness or itching in very sensitive individuals
- Contact dermatitis in people allergic to amine or maleate compounds
- Eye irritation if the product accidentally drips into the eyes
- Dryness or stiffness when overused in high-protein routines that lack adequate moisturizers
If any discomfort or adverse reaction occurs discontinue use and consult a healthcare professional.
Comedogenic Rating
Rating: 0 (non-comedogenic). Propylenediammonium Dimaleate is highly water soluble and lightweight so it rinses away without leaving an oily film that could block pores. Its structure lacks fatty chains or waxy residues linked to breakouts, making it very unlikely to clog follicles.
It is therefore suitable for acne-prone or breakout-prone skin.
No data indicate it worsens fungal acne or seborrheic dermatitis, but remember that other ingredients in the same product could affect overall pore friendliness.
Summary
Propylenediammonium Dimaleate is a bond-building hair conditioner that strengthens internal hair links which reduces breakage, boosts shine and leaves strands smoother and easier to style. Its water compatible nature lets it penetrate the hair shaft, support disulfide bonds then rinse clean without weight.
After debuting in salon bond-repair systems it is gaining traction in at-home masks and leave-ins, though it remains less common than staples like keratin or panthenol.
Safety data show a low risk profile with only occasional mild irritation reports. Still, everyone’s skin is unique so patch testing a new product that contains it is wise just to be safe.