What Is Diisopropyl Adipate?
Diisopropyl adipate is a clear lightweight liquid made by reacting adipic acid, a dicarboxylic acid, with isopropyl alcohol. This reaction, called esterification, joins the two components while removing water, creating an ester that is stable and easy to blend with oils. The process is carried out in large stainless-steel reactors where heat and a catalyst speed up the reaction, after which the mixture is purified and filtered for cosmetic use.
Although adipic acid is often sourced from petrochemicals, newer methods can start with plant-derived feedstocks like corn glucose that is fermented into bio-based adipic acid. Isopropyl alcohol is typically synthetic. The finished ester has been used since the 1950s as a plasticiser in flexible plastics and soon found its way into personal care when formulators noticed its smooth silky feel on skin.
Thanks to its low viscosity, quick spreadability and ability to dissolve both oily and some water-soluble ingredients, diisopropyl adipate shows up in sunscreens, facial moisturizers, body lotions, lightweight facial oils, anti-aging serums, sheet masks, makeup primers, foundations, deodorants and hair conditioners. It helps these products apply evenly, feel non-greasy and stay stable on the shelf.
Diisopropyl Adipate’s Cosmetic Benefits/Uses
Formulators reach for diisopropyl adipate because it can play several helpful roles in one formula
- Fragrance: Acts as a carrier that dilutes perfume oils and helps them evaporate at a balanced rate so the scent lasts longer without overpowering the senses
- Plasticiser: Softens film-forming polymers in products like sunscreens and makeup, preventing cracking and giving flexible comfortable wear
- Skin conditioning: Leaves skin feeling soft and smooth by forming a thin flexible layer that reduces moisture loss
- Emollient: Fills in tiny gaps between skin cells giving an immediate silky after-feel that can make dry or rough skin appear healthier
- Solvent: Helps dissolve UV filters, vitamins and other active ingredients so they spread evenly and stay stable, improving overall performance of the product
Diisopropyl adipate is generally well tolerated by most skin types, including normal, dry and combination. Its light texture and non greasy finish make it comfortable even for oily skin, although those who are extremely acne prone may prefer to monitor how their skin responds since any emollient can feel too rich for some.
The ingredient is synthesized from adipic acid and isopropyl alcohol, both of which can be sourced from petrochemicals or bio based feedstocks, so no animal derived materials are involved. This makes diisopropyl adipate suitable for vegetarians and vegans.
Current research and safety reviews have not flagged diisopropyl adipate as a concern for pregnant or breastfeeding women when used in typical cosmetic concentrations. That said this is not medical advice and anyone who is pregnant or nursing should have a chat with a healthcare professional before starting a new product to be on the safe side.
Diisopropyl adipate does not increase photosensitivity. In fact it is often paired with sunscreen filters to improve spreadability and film formation. There are no known ingredient incompatibilities that rule out its use alongside common actives like retinoids, vitamin C or exfoliating acids.
Potential Side Effects/Adverse Reactions
Every individual’s skin is unique so reactions to topical diisopropyl adipate can vary. The effects listed below are potential issues only and most users will not encounter them when the ingredient is used correctly in a well formulated product.
- Mild skin irritation – sensitive skin may experience temporary redness or stinging, especially if the overall formula contains high levels of fragrance or other irritants
- Contact dermatitis – in rare cases an allergic response can occur leading to itching, rash or swelling
- Acne flare-ups – individuals with very congested or acne prone skin might notice clogged pores if the rest of the product is rich or occlusive
If you notice persistent irritation, breakouts or an allergic reaction stop using the product and consult a healthcare professional for guidance.
Comedogenic Rating
Rating: 2 out of 5. Diisopropyl adipate is a light ester that spreads quickly and does not leave a heavy film, so it is less likely to block pores than thick plant oils or waxes. Still, it is an emollient and can mingle with sebum inside a clogged follicle which is why it earns a low-to-moderate score rather than a zero. Most people with normal, dry or combination skin will have no issues but highly acne-prone users might prefer to watch how their skin reacts.
The rating can shift slightly depending on the full formula: if the product also contains rich butters or occlusive silicones, the overall pore-clogging risk rises; in a weightless gel lotion it remains low.
Summary
Diisopropyl adipate acts as a fragrance carrier, plasticiser, skin conditioner, emollient and solvent. Its small, slick molecules soften polymer films, dissolve tricky actives and glide over skin to leave a silky non greasy finish that locks in light moisture.
You will spot it most often in sunscreens, primers and lotions where a smooth feel is prized, though it is not as hyped as ingredients like hyaluronic acid or squalane. Formulators appreciate its versatility so it quietly shows up in many backstage roles.
Current safety data rates it as low risk for irritation or toxicity at the levels used in cosmetics. Still, skin is personal so try a small patch when testing any new product that contains diisopropyl adipate to make sure it suits your individual needs.