What Is Myristalkonium Chloride?
Myristalkonium chloride is the cosmetic name for benzyldimethyltetradecylammonium chloride, a quaternary ammonium compound created by combining a long chain fatty alcohol with a benzyl dimethyl ammonium group. The process usually starts with naturally derived myristyl alcohol from sources like coconut or palm oil. Chemists react this alcohol with dimethylbenzylamine and then quaternize the mixture with hydrochloric acid, giving a water-soluble salt that works well in skincare and hair care formulas.
The ingredient first appeared in personal care products in the mid 20th century when formulators were searching for mild yet effective ways to keep creams and lotions free from microbial growth. Its broad-spectrum activity against bacteria and fungi quickly made it a reliable alternative to traditional preservatives. Today it is manufactured on an industrial scale under strict quality controls to meet cosmetic grade standards.
You will most often see myristalkonium chloride in rinse-off hair conditioners, leave-in treatments, facial masks, moisturizers and some anti aging serums. Brands choose it for products that need to stay fresh over time without changing the feel or scent of the formula.
Myristalkonium Chloride’s Cosmetic Benefits/Uses
In cosmetics myristalkonium chloride serves a single but important role
Preservative: It inhibits the growth of bacteria, yeast and mold in water-based products helping extend shelf life and protect users from contamination. Because it works in low concentrations it keeps formulas stable while maintaining a pleasant texture and appearance
Who Can Use Myristalkonium Chloride
Products preserved with myristalkonium chloride are generally well tolerated by normal, dry, oily and combination skin because the ingredient is used at very low concentrations that stay on the surface rather than penetrating deeply. Highly sensitive or compromised skin may occasionally find quaternary ammonium compounds a bit drying or irritating, so individuals in that group should pay closer attention to how their skin feels when trying a new formula.
The raw materials employed to make myristalkonium chloride come from plant-based fatty alcohols like coconut or palm oil and the rest of the process is synthetic, so the final ingredient contains no animal-derived substances. This makes it acceptable for vegans and vegetarians, provided the finished product is not tested on animals and meets their personal ethical standards.
Current safety assessments have not flagged myristalkonium chloride as a concern for women who are pregnant or breastfeeding when used topically at the levels allowed in cosmetics. Nonetheless this is not medical advice and anyone who is pregnant or nursing should have their doctor review any skincare or hair care product they plan to use just to be safe.
The ingredient is not known to increase photosensitivity and it does not react with sunlight, so regular daytime use does not require extra sun precautions beyond the daily SPF already recommended for healthy skin.
Potential Side Effects/Adverse Reactions
Responses to topical myristalkonium chloride vary from person to person. The effects listed below are only potential outcomes and are unlikely to occur for most people when the ingredient is used at the low amounts permitted in cosmetics.
- Skin irritation Mild redness stinging or dryness may appear especially on very sensitive skin
- Contact allergy In rare cases repeated exposure can trigger an allergic rash or eczema-like reaction
- Eye irritation If a product containing the preservative gets into the eyes it can cause watering burning or temporary discomfort
- Exacerbation of existing dermatitis People with active eczema or broken skin might notice increased itching or flare-ups in the affected area
If any of these issues occur stop using the product immediately and consult a healthcare professional for guidance.
Comedogenic Rating
Rating: 0 / 5
Myristalkonium chloride is a water-soluble quaternary ammonium salt that stays dissolved in the watery phase of a formula rather than sitting on the skin’s surface or mingling with skin oils. Because it has no oily or waxy characteristics it does not block pores or create the kind of film that can trap sebum and dead cells. For that reason formulators consider it non-comedogenic.
People who are prone to acne or frequent breakouts can generally use products preserved with myristalkonium chloride without worrying about extra congestion.
Most products containing this ingredient are rinse-off conditioners or lightweight leave-ins, further reducing any chance of pore blockage.
Summary
Myristalkonium chloride works in cosmetics as a broad-spectrum preservative that keeps bacteria yeast and mold from growing in water-based formulas. It does this by disrupting microbial cell membranes at very low concentrations which lets products stay fresh and safe over their intended shelf life.
It is not one of the beauty industry’s trendiest ingredients but it remains a reliable background player in hair conditioners masks and some skin treatments where a clear odorless preservative is needed.
Current research and regulatory reviews show it is safe for topical use at the small levels allowed in cosmetics with only rare reports of irritation or allergy. As with any new product it is smart to do a quick patch test first to make sure your skin agrees with the full formula.