What is "slugging" and is this a new practice?
Slugging is the current term used to describe applying a thin layer of an ultra-occlusive product, typically 100% petrolatum on your skin as the last step of your skincare routine. The name ‘Slugging’ comes from the shell-less mollusc, slug, which produces a slime-like layer of water plus salt plus mucus resembling petroleum jelly. Slugging is trending on social media, but this practice is not new. Dermatologists recommend full face application of petrolatum in many scenarios including after cosmetic laser or injection treatments, after surgical procedures, after skin rashes, and for those with extremely sensitive or eczema prone skin.
Is slugging safe for your skin?
Petrolatum or petroleum jelly is composed of synthetic hydrocarbons which are inert and have essentially no potential for causing allergic reactions. Due to the chemical structure Petrolatum functions very well as an occlusive skin barrier which prevents Transepidermal Water Loss (TEWL).
Many but not all skin types can tolerate slugging. When an occlusive like Petrolatum covers a large area of skin some individuals could develop folliculitis (inflammation around hair follicles), miliaria (inflammation around sweat ducts) or even acne. For those who commonly develop facial acne breakouts, I recommend avoiding the use of petrolatum. Instead, a light layer of a serum with humectants may be enough.
Does it clog your pores?
Occlusive products like Petrolatum create an impermeable barrier wherever it is applied. If the product is applied to skin with hair follicles and eccrine glands (sweat glands and ducts) then those areas will be temporarily blocked ("clogged pores"). This is the goal of an occlusive, to create this barrier so that substances in the outside world do not come into contact with that particular area of skin. The parallel goal is to prevent that area of skin from losing (via evaporation) hydration. This helps skin repair, rehydrate and rest.
How often should you "slug"?
If your skin tends to run dry or if the humidity is very low, you can likely slug every other night. Otherwise, about once per week is more than enough.
Can you do slugging with products that have petroleum but are not Vaseline?
To clarify, Vaseline is simply a brand and makes multiple products, most have petroleum but some do not have petroleum. Most slugging discussed in media refers to products that are 100% petroleum. So can you use something that is not 100% petroleum?
Yes, you can definitely slug other occlusive products, not necessarily 100% petroleum. Products like Aquaphor, CeraVe Healing ointment, and Vaniply. Note - these other products have multiple added ingredients unlike 100% petroleum. This creates a slightly increased risk of allergic or irritant reaction.
You can also slug using plant-based oils and butters. Possible ingredients to look for include Jojoba oil, squalane, coconut oil and shea butter. I would not recommend 100% oil for slugging since the oil will run off your skin, and instead the aforementioned oils should be an ingredient to form a thick cream or butter. These oils have fatty acids, wax esters, triglycerides and properties that mimic our skin’s natural sebum so they function biologically similar to our normal skin.
A nourishing emollient like the KP Away Lipid Repair Emollient contains humectants as well as occlusives. The Lipid Repair Emollient is formulated with Organic Coconut Oil, which is shown in clinical studies to be extremely effective in preventing TEWL. Body butters are another great alternative to petrolatum-based balms. Skintensive’s Body Butter has a mix of Coconut oil, Ceramides, and Seabuckthorn Berry to nourish the skin overnight. Overnight face masks can be a great option as well - Sweet Chef’s Beet + Retinol Night Firming Mask has a mix of Squalane and Hemp Seed Oil.