What Is Stearaminocarbonyl Benzophenone-4?
Stearaminocarbonyl Benzophenone-4 is a lab made organic compound built from a benzophenone core that has been linked to a long stearyl chain. The stearyl part is a fatty segment found in plant and animal fats while the benzophenone piece is common in many light absorbing materials. Chemists first explored benzophenone derivatives in the mid 20th century when they looked for agents that could create thin protective films on surfaces. By adding the stearyl chain researchers found the molecule became easier to blend into creams and lotions, which opened the door for cosmetic use.
Production starts with benzophenone-4, a known UV filter, then reacts it with stearamine and a carbonyl activating agent in a controlled environment. The reaction joins the fatty chain to the aromatic core, after which the mixture is purified and dried to a fine powder or waxy flakes. Because the raw materials are plentiful and the process is straightforward, the ingredient is affordable for large scale skin care production.
You will most often see Stearaminocarbonyl Benzophenone-4 in leave on products that need a lightweight barrier such as daily moisturizers, primers, BB creams, facial masks, styling gels and some anti aging serums. It can also appear in water resistant sunscreens and color cosmetics where a smooth, flexible film is desired to keep pigments or actives in place.
Stearaminocarbonyl Benzophenone-4’s Cosmetic Benefits/Uses
Formulators choose this ingredient for one key reason
Film forming: When applied to skin or hair the molecule spreads out and sets into a thin invisible layer. This soft film helps lock in moisture, makes the surface feel silky and boosts the lasting power of other ingredients like pigments, emollients or UV filters. It can also give a slight water resistance which is helpful in long wear or outdoor products.
Who Can Use Stearaminocarbonyl Benzophenone-4
This film former sits lightly on the skin so it suits most skin types including oily, combination, dry and even mildly sensitive skin. Extremely reactive or eczema-prone skin should proceed with caution because any added barrier ingredient can sometimes trap heat or sweat and trigger flare-ups.
The compound is synthesized in a lab from petrochemical and plant-derived building blocks, not animal sources, so it is generally considered suitable for vegetarians and vegans. If a brand claims otherwise check for animal-based processing aids that could be used in the larger formula.
Published safety data show no specific reproductive toxicity so products containing Stearaminocarbonyl Benzophenone-4 are not flagged as off-limits for those who are pregnant or breastfeeding. This is not medical advice and anyone expecting or nursing should still confirm product choices with a healthcare professional.
The ingredient is not known to cause photosensitivity. In fact its benzophenone backbone can help stabilize formulas that sit in the sun, though it is not meant to replace broad spectrum sunscreen filters. There are no reported interactions with common actives like retinol or vitamin C so it can slot into most routines without conflict.
Potential Side Effects/Adverse Reactions
Responses to topical Stearaminocarbonyl Benzophenone-4 differ from person to person. The effects listed below are possible yet uncommon when the ingredient is used at the low levels found in finished cosmetics.
- Mild skin irritation – slight redness or warmth at the application site usually subsides after product removal
- Contact dermatitis – in rare cases users with pre-existing fragrance or resin allergies may experience itching or rash
- Eye irritation – if the product migrates into the eyes it can cause stinging or watering until rinsed out
- Temporary pore congestion – heavy layers may trap oil leading to small bumps in very acne-prone skin
If any of these effects occur discontinue use and seek medical guidance if symptoms do not improve promptly.
Comedogenic Rating
Rating: 2 out of 5
Stearaminocarbonyl Benzophenone-4 carries a long fatty chain that can sit on the skin and form a light seal, which could marginally block pores in people who clog easily. However it is typically used at low concentrations and sets into a breathable film rather than a thick grease, so its pore-blocking potential stays modest.
Most acne-prone users should tolerate it, but those extremely sensitive to any occlusion might want to monitor their skin for congestion.
No reports link this ingredient to fungal acne flare-ups, and it does not feed Malassezia yeast, which is helpful for anyone managing that specific concern.
Summary
Stearaminocarbonyl Benzophenone-4 is mainly a film former that spreads into a thin flexible layer, locking in moisture and helping pigments, emollients and UV filters cling longer to skin or hair. Its blend of a light-absorbing benzophenone core and a stearyl tail lets it dissolve well in creamy bases and adds mild water resistance.
The ingredient is a niche pick rather than a blockbuster, appearing more in specialized primers, long-wear creams and hybrid sunscreens than in everyday lotions.
Current safety reviews rate it as low risk with only occasional mild irritation or congestion reported. As with any new product it is smart to patch test before full use to make sure your skin agrees with the formula.