Learn all about occlusives in skincare, and how they can be used to support your skin barrier, thus encouraging healthier and clearer skin. Acne sufferers – I got you covered with peer-reviewed, scientific research articles that will help you to implement this type of product into your routine!
We constantly hear about typical acne treatments that cause dry, irritated, and flaky skin. The fact is that these acne treatments must be used in conjunction with nourishing, barrier repairing ingredients that will actually allow those treatments to work their magic. A key factor in all of this includes occlusives in your routine. Let’s start with a simple introduction.
Occlusives, The Answer to Transepidermal Water Loss
The stratum corneum refers to the outer layer of our skin. It is made up of keratin, a fibrous protein, and skin cells that are connected by filament proteins (1). The skin barrier refers to the processes that the skin implements in order to keep it healthy and functioning. This includes maintaining the water content in the skin, its ability to fight against external stressors such as UV rays, and how it responds to microbes and other antigens (2).
In order to maintain the skin barrier, we must treat our skin gently and incorporate moisturizing ingredients that will help prevent transepidermal water loss (TEWL). TEWL is the loss of water from the skin, which leads to skin dryness and a compromised barrier. This occurs when we use harsh cleansers, incorporate drying ingredients, or skip moisturizer. To aid in preventing TEWL from occurring, an occlusive will be able to help.
An occlusive ingredient in skincare describes a substance that physically blocks water from leaving the skin, allowing your skin to lock in moisture (3). When applied, occlusives form a barrier on the top of the skin. An example of an occlusive ingredient is petroleum jelly. It can prevent TEWL up to 98%, keeping moisture in the skin (3). Read more about Vaseline and how it can improve conditions like post-inflammatory erythema (PIE) here. In addition to fading PIE, using an occlusive ingredient can help to maintain the skin barrier, which ultimately allows the skin to repair itself and heal your acne. Occlusives also protect the skin against environmental irritants, preventing further breakouts that may be triggered by external stressors and pollutants.
Silicones as Occlusive Ingredients
Silicones, such as dimethicone, are another type of occlusive ingredient that can be used to lock in moisture in the skin (4). However, it forms a much more permeable barrier over the skin in comparison to petroleum jelly. Regardless, the use of silicones has been shown to reduce TEWL when applied to the skin (5). It also imparts a lubricating effect and smooths the skin (6). This can help the skin stay healthy, preventing bacteria and other pollutants from irritating the skin and causing acne.
Oils as Occlusive Ingredients
Certain types of plant oils can have an occlusive effect on the skin, preventing TEWL and helping the skin to keep moisture levels in check (7). Vegetable oils, except for jojoba oil, were shown to have similar occlusive properties to paraffin oil (a type of mineral oil) and can effectively prevent TEWL (8). Specifically, saturated fatty acids including palmitic and stearic acid can form an occlusive film on top of the skin. An example of an oil that includes these fatty acids is sea-buckthorn oil (9).
Sea-Buckthorn Oil For Acne
Topical application of sea-buckthorn oil has been shown to soften the skin and increase skin regeneration (9). It is especially beneficial to those suffering from acne as it reduces inflammation in the skin. Sea-buckthorn oil also contains sterols, which are wax-like substances, that impart an occlusive effect on the skin, keeping moisture in the epidermis and maintaining the skin barrier (9).
You may not be surprised to know that oral consumption of sea-buckthorn oil also has amazing benefits for the skin. This oil contains palmitoleic acid, a type of fatty acid that has been shown to reduce hyperpigmentation in the skin by inhibiting an enzyme that plays a role in forming dark spots (10). Oral administration of sea-buckthorn oil in a capsule form promoted a decrease in inflammation in the body (10).
Sea-buckthorn oil is also rich in linoleic acid, a type of fatty acid that is reduced in those suffering from acne. Oral consumption of this seed oil has been shown to maintain the lipid barrier of the skin, reduce TEWL, and prevents the formation of acne by increasing the levels of linoleic acid in the skin (10).
Not All Oils Are Kind To Skin
Sea-buckthorn oil is a prime example of a great oil that has many benefits for the skin. However, it’s important to note that just because many people tout the benefits of plant oils doesn’t mean that science backs those claims! For example, let’s take olive oil. Some may think this is a relatively harmless oil. However, research has shown that topical application of olive oil actually increases TEWL, weakens the skin barrier, and reduces the integrity of the structure of the stratum corneum (7). Be careful with the oils you choose to add to your routine, and always make sure to conduct research beforehand.
How To Use Occlusives In Your Skin Care Routine
Depending on the type of occlusive ingredient you choose to incorporate into your skin care routine, the order in which you apply it will vary.
Let’s consider you have a basic morning skincare routine that consists of a cleanser, moisturizer, and sunscreen. (Click here for a recommended skincare routine from The Ordinary). Where can you fit an occlusive containing silicones into your routine? Your best bet is to avoid heavy occlusives in the morning, as this may feel uncomfortable throughout the day. You want to look for a moisturizer or light serum that contains silicones, such as dimethicone, that will provide some sort of occlusive effect to the skin, but still allow your skin to be permeable if you are adding other skin care ingredients on top.
As mentioned earlier, oils can impart an occlusive effect on the skin. It is recommended that oils are used in the evening before bed to avoid an uncomfortable or greasy feeling throughout the day if you were to apply them in the morning. It’s best to put oils on after your nighttime serum and/or moisturizer, since oils may feel heavier on the skin. Once you apply your serum (if you choose to use one), followed by your moisturizer, you can apply 2-3 drops of your favourite occlusive oil, like sea-buckthorn oil, and gently rub into the skin.
As mentioned earlier, Vaseline contains petroleum jelly, which prevents TEWL up to 98%. It is imperative that you add Vaseline as the last step in your routine, regardless of your other skin care products. The reason? If you apply Vaseline first, and then apply moisturizer, it will create a barrier on the skin, preventing your moisturizer from sinking into the skin. So, it is best to use it as the last step, preferably at night, allowing your skin to lock in moisture from all of your hydrating skin care ingredients.
(1) Takeshi Matsui, Masayuki Amagai, Dissecting the formation, structure and barrier function of the stratum corneum, International Immunology, Volume 27, Issue 6, June 2015, Pages 269–280, https://doi.org/10.1093/intimm/dxv013
(2) Rosso JD, Zeichner J, Alexis A, Cohen D, Berson D. Understanding the Epidermal Barrier in Healthy and Compromised Skin: Clinically Relevant Information for the Dermatology Practitioner: Proceedings of an Expert Panel Roundtable Meeting. J Clin Aesthet Dermatol. 2016 Apr;9(4 Suppl 1):S2-S8. Epub 2016 Apr 1. PMID: 28936279; PMCID: PMC5608132.
(7) Lin TK, Zhong L, Santiago JL. Anti-Inflammatory and Skin Barrier Repair Effects of Topical Application of Some Plant Oils. Int J Mol Sci. 2017 Dec 27;19(1):70. doi: 10.3390/ijms19010070. PMID: 29280987; PMCID: PMC5796020.
(8) Patzelt, A., Lademann, J., Richter, H., Darvin, M. E., Schanzer, S., Thiede, G., Sterry, W., Vergou, T., & Hauser, M. (2011, November 14). In vivo investigations on the penetration of various oils and their influence on the skin barrier. Wiley Online Library.
(10) Solà Marsiñach M, Cuenca AP. The impact of sea buckthorn oil fatty acids on human health. Lipids Health Dis. 2019 Jun 22;18(1):145. doi: 10.1186/s12944-019-1065-9. PMID: 31228942; PMCID: PMC6589177.