Light and heavy skin oils: what are the differences? - Iconic Elements by dr. Wu (2024)

Skin oils are essential for healthy skin. They help to protect, hydrate and repair the skin. There are many different skin oils on the market, varying in composition, properties and uses. In this blog post we discuss the differences between light and heavy skin oils. We explain why they are so different and which skin oils are comedogenic.

Light and heavy skin oils

The lightness or heaviness of a skin oil has to do with the composition of the oil. Oils high in unsaturated fatty acids tend to be light, while oils high in saturated fatty acids tend to be heavy.

Unsaturated fatty acids are liquid at room temperature, while saturated fatty acids are solid at room temperature. Unsaturated fatty acids are also smaller than saturated fatty acids, making them easier to absorb through the skin.

How is it classified?

Molecular Weight:

Molecular weight is a measure of the mass of a molecule, expressed in Dalton (Da). It is calculated by the sum of the atomic weights of all atoms in a molecule. Here’s a deeper explanation of how molecular weight affects the properties of light and heavy oils:

1. Light oils:
   • Lower molecular weight: The molecules in light oils are generally smaller and weigh less.
   • Fast absorption: Due to their lighter weight, these smaller molecules can easily penetrate the skin, resulting in faster absorption.
2. Heavy oils:
   • Higher molecular weight: The molecules in heavy oils are larger and have a higher weight.
   • Slower absorption: Due to their greater mass, these molecules take longer to penetrate the skin layers, causing slower absorption.

The molecular weight therefore influences the penetration speed of oils into the skin. Light oils with smaller molecules are absorbed quickly, while heavy oils with larger molecules show slower absorption.

Consistently

• Light oils: Remain liquid at room temperature and have no tendency to solidify.
• Heavy oils: May solidify slightly at lower temperatures due to their more complex composition. For example, coconut oil has a solid consistency and between 24 and 25 degrees Celsius it becomes liquid.

Texture

• Light oils: Feel thinner and are quickly absorbed, making them ideal for everyday use and for oily skin.
• Heavy oils: Have a richer, thicker texture and can be more suitable for intensive hydration, especially at night.

Absorption speed

• Light oils: Are quickly absorbed by the skin, making them suitable for quick hydration without a sticky feeling.
• Heavy oils: Require more time to be fully absorbed by the skin, making them ideal for long-lasting hydration.

The choice between light and heavy oils depends on individual skin needs, preferences and intended use.

Light oils

Light oils have a molecular weight of less than 300 Da. They are usually liquid at room temperature and have a thin, oily texture. Light oils are quickly absorbed by the skin and do not leave a greasy layer.

1. Jojoba Oil: Similar to the skin’s natural oils. Suitable for all skin types.
2. Argan oil: Quickly absorbed, non-greasy. Rich in vitamin E and essential fatty acids.
3. Grape seed oil: Suitable for oily skin.
4. Apricot kernel oil: Light and soothing, suitable for sensitive skin.
5. Rosehip oil: Rich in vitamin C and supports the fading of scars.

Heavy oils

Heavy oils have a molecular weight of more than 300 Da. They are usually solid at room temperature and have a thicker, oily texture. Heavy oils are absorbed more slowly by the skin and leave a greasy film.

1. Olive oil: Richer and slightly heavier. Good for dry skin.
2. Coconut oil: Semi-solid at room temperature, becomes liquid on the skin. Moisturizing but can be comedogenic for some people.
3. Avocado oil: Nourishing and suitable for dry, mature skin.
4. Shea Butter: A buttery substance, very nourishing. Great for very dry areas.
5. Sweet Almond Oil: Slightly heavier than jojoba oil, moisturizing and suitable for normal to dry skin.

Oils cause pimples and are comedogenic?

Some skin oils can be comedogenic. This means that they can cause blackheads. Comedones are small, white or black bumps that form in the pores of the skin.

The comedogenicity of a skin oil is determined by the composition of the oil. Oils high in saturated fatty acids are generally more comedogenic than oils high in unsaturated fatty acids.

This is because saturated fatty acids are harder molecules than unsaturated fatty acids. Hard molecules are more difficult to penetrate the skin, so they can build up in the pores. This can lead to clogging of the pores and the formation of blackheads.

Unsaturated fatty acids, on the other hand, are softer molecules that are more easily absorbed by the skin. So they are less likely to cause blackheads.

Comedogenic skin oils include:

• Cocoa butter
• cocos oil
• Linseed oil
• Palm oil
• Soy oil
• Wheat germ oil
• Carrot seed oil

Non-comedogenic skin oils include:

• almond oil
• Argan oil
• Avocado oil
• Hempseed oil
• Jojoba oil
• Olive oil

It is important to remember that the comedogenicity of a skin oil can be different for everyone. Some people may be more sensitive to comedogenic oils than others.

If you have acne, it is important to choose a skin oil that is non-comedogenic. You can do this by looking at the composition of the oil. Oils high in unsaturated fatty acids are generally safer for people with acne.

You can also do a comedogenicity test. This test is performed by applying a small amount of the oil to a small area of ​​skin. If the skin is red, irritated or with blackheads after 24 hours, the oil is probably comedogenic.

What about mineral oil – comedogenic or not?

Mineral oil is known to be non-comedogenic. Comedogenic refers to substances that tend to cause blackheads (comedones), which can lead to clogged pores and acne. Mineral oil is derived from petroleum and is often used in skin care products for its moisturizing properties. It falls under the occlusive moisturizer group. Retains the moisture in the skin by physically blocking it. This stops moisture loss from the skin.

Know more about: dry skin and different types of moisturizers

Mineral oil is chemically stable and has a large molecular size, which means it does not easily penetrate the pores of the skin. Because of this, it is generally considered safe for use even in those with a tendency toward acne. It does not clog pores and has no known comedogenic properties.

Learn more: Skin advice – Acne

In other words

The choice of a light or heavy skin oil depends on both your skin type and your personal preferences. Light oils are ideal for people with oily or combination skin, as they are quickly absorbed into the skin without leaving a heavy feeling. On the other hand, heavy oils are more suitable for people with dry or sensitive skin, as they are absorbed more slowly and can intensively moisturize the skin. It’s important to understand your skin’s unique needs and experiment with oils to discover which ones work best for you.

While you are here

Which skin oil suits your skin problem best?

With countless oils on the market, it can be difficult to make the right choice for your specific skin challenge. In our extensive blog we take a closer look at natural oils that can be effective for common skin problems such as dryness, acne, eczema, signs of skin aging and pigment spots. Learn what to look for when selecting a skin oil and discover essential tips for effective use. Click here to read the blog.