Isododecane is a common ingredient found in many different types of beauty products. This colorless liquid is often added to cosmetics and other personal care products to keep them soft and to help them glide easily on the skin.

But with anything you use on your body it’s important to know about the ingredients that are in them and how safe they are.

Here we break down the most important need-to-know information regarding isododecane.

Due to its chemical makeup, isododecane is used in a wide variety of beauty products. These include personal care items, such as moisturizers, as well as makeup and hair care products. You may find the ingredient in the following:

  • lipstick (especially long-wear formulas)
  • foundation
  • mascara
  • eyeliner
  • skin serums
  • moisturizers
  • shampoo
  • conditioners
  • hair serums
  • hairspray

Isododecane is a solvent, as well as an emollient. In layman’s terms, this means that the ingredient:

  • helps retain moisture
  • breaks down easily for smooth application
  • spreads easily on the skin without leaving a thick or greasy residue
  • helps create a “matte” finish for lipstick, cheek color, and foundation
  • minimizes the transfer of color (e.g., lipstick marks on cups and silverware)
  • helps provide a “weightless” feel

Studies on the safety profile of isododecane are limited. However, the Cosmetic Ingredient Review Expert Panel reviewed relevant animal and clinical data in 2012 and deemed it safe when used in low concentrations, as is the case with most beauty products.

If you have sensitive skin, you may want to check with a dermatologist before using this ingredient. While no current studies show that isododecane is harmful to any skin type in particular, your skin care professional can provide advice based on your type of skin and your skin’s level of sensitivity.

Few studies have looked at the possible side effects of isododecane. This is likely due to the fact that its chemical properties are considered safe when used in small amounts.

Isododecane is just one of many ingredients used in your beauty products. Such trace ingredients are usually unlikely to cause significant harm.

Still, there’s always the possibility of an allergic reaction. One of the most common side effects associated with ingredients in beauty products is a condition called contact dermatitis.

The most common form of contact dermatitis is called irritant contact dermatitis. This happens when the protective layer of your skin is irritated by something that touches it.

The most common symptoms of irritant contact dermatitis include:

  • redness
  • rash
  • bumps and blisters
  • itchiness
  • burning
  • scaly, cracked skin

A less common form of contact dermatitis is allergic contact dermatitis.

While symptoms of irritant contact dermatitis typically develop quickly, it can take 48 to 96 hours for the skin to develop a reaction with allergic contact dermatitis. The symptoms are typically the same as those for irritant contact dermatitis.

Isododecane is often one of many ingredients used in a beauty product. If you develop an allergic reaction, it can be difficult to determine if this particular ingredient is the cause.

To help figure this out, you may want to see a dermatologist and take all your beauty items with you. Your doctor can take a closer look at the ingredients and, based on your skin type and sensitivities, help you get to the bottom of which ingredients may be causing a reaction.

Due to its wide use and lack of reported side effects, isododecane is most likely safe for most people. This is especially the case for products that use extremely low concentrations of this ingredient.

However, it’s possible to develop a reaction to any skin care or makeup ingredient. If you develop a reaction to a product with isododecane, stop using it. Follow up with a dermatologist to find out if you should avoid this ingredient, and which products are safe to use.