Slugging – why is everybody doing it, and how to do it properly?

I think the best place to start is to acknowledge that we need to rename this new skincare trend, as honestly, nobody likes the idea of slugs, or putting anything that resembles slugs onto their face!

Ok, so we’re not actually putting slugs on our face (albeit I imagine there’s probably some merit in that considering their mucus is hygroscopic), however…. it’s just not the vision I’d like to associate with skincare, which should be a positive exercise in self-care, as well as highly effective. More on re-naming later…

The Korean beauty trend that has taken the world by storm involves generously applying a petroleum-based product to your face as the last step in your evening skincare routine to help lock-in and seal your beauty products overnight. Done traditionally, it creates a seal over the skin, prevents trans-epidermal water loss (dehydrated skin) and protects the lipid skin barrier (which if damaged – causes dehydration and a myriad of other problems). In effect, when the skin barrier and its function is compromised, slugging is an artificial way to reinforce this protective wall.

First let’s explore the concept of slugging and why it can be beneficial.....

Why slugging can be beneficial?

As a massive advocate of finding the root cause of any problem (rather than simply masking over the resulting symptoms), let’s go a little deeper, and look at why you can end up with a compromised skin barrier in the first place. Considering the vast array of products that marketing is telling us to apply on a daily basis, you may be surprised to hear what can actually cause this.

Compromised skin barrier?

Over the last few years we’ve been led to believe that the more facial products we use in our routine, the better. Who doesn’t love an array of products on their bathroom shelf; the aromas, the textures and the aesthetically pleasing packaging? As a result, bathroom cabinets are full of different ablutions that specifically target either lines and wrinkles, pores, the skin barrier, dry skin, acne, or skin firmness and so on. The encouragement of multiple skin product applications is a great marketing tool for brands in terms of sales, but ultimately it’s unnecessary. It may seem like the right direction to go in by having one product per skin objective, but by using multiple products, and from multiple brands (without any advice as to how to use them either singularly or together), we can often be doing more harm than good.

As just one example, a retinoid-based product that is used alongside an AHA/BHA product is going to send skin into a tinsel-town meltdown, and more so if you have sensitive skin to begin with.  Chemically exfoliating the skin (AHA/BHAs), at the same time as rapidly increasing skin cell turnover (retinoids) will leave your skin shocked, irritated, dry and vulnerable. Applying Vitamin C and retinoids or Vitamin C and AHAs are further ways to reduce the integrity of the skin barrier without even visibly noticing what you’ve done.

So, we’ve touched on multiple product applications with contraindications and the damage they can cause, but there are much simpler (and dare I say easier) ways to damage the skin barrier which include:

Using AHAs (alpha-hydroxy acids) and BHAs (beta hydroxy acids) during the day

These chemical exfoliants dissolve dead skin cells to reveal fresh new radiant skin underneath. Even if using AHA/BHAs on their own, applying these ingredients either during daylight hours, and/or not using sufficient SPF is looking for trouble in terms of both skin health, and….premature ageing. It’s like saying to the ball of fire in the sky, ‘hey there, I’m naked right now, please take advantage and penetrate my delicate new skin cells.’ It’s just not a good idea! The new skin is incredibly sensitive and the sun’s rays have brutal effects, even when it looks positively grey outside.

It’s also not a good idea to use BHAs if you already have dry skin, because they tend to pull oil out of pores, exacerbating dehydration (just one end-result of already having a compromised skin barrier).

Combined SPF moisturisers

A number of day creams and make-up foundations now include SPF. Naturally we like to trust that what we read on packaging is legitimate and therefore presume that we’re doing everything we possibly can to protect our skin if we use a product with an SPF rating, however, this isn’t always the case. Due to the way combined moisturiser/SPF products are formulated, the protection you physically receive will often be significantly lower than the rating you see on the box. A study presented at the British Association of Dermatologists (BAD)’s annual meeting concluded that ‘moisturisers with sun protection factor (SPF) provide less sun protection than the equivalent strength sunscreen in real-world scenarios.’

These combined products face multi-faceted problems:

  • Absorption levels linked to poor SPF efficacy


  • Application methods linked to poor SPF efficacy.

Researchers from Liverpool used a specially modified camera that captures UV light to assess how participants applied regular SPF versus moisturiser containing SPF. Areas of skin that were efficiently covered in a stand-alone SPF product appeared black, whereas participants who had applied a combined SPF moisturiser, the skin was comparatively lighter, suggesting less SPF absorption. When we talk of how we actually apply these combined moisturisers, it’s also a case of ‘oops missed a bit!’ When you’re on holiday and you miss a bit of bottom cheek you only realise once it’s too late and can’t sit down for the rest of the week! This is an extreme example, but when applying moisturiser, we often do the same, albeit to our eyelids, tops of the ears, neck and décolletage. The mindset we’re in when repetitively getting ready for work each day or running out of the door for odd errands is simply not the same as when we’re lolopping on a sun lounger. If we’re honest, unless you’re on holiday, or you live in a hot country, our daily facial preparation does not scream ‘UV danger zone,’ so how does this make a difference to our skin health? We often apply our moisturiser in a hasty slap dash type manner whilst thinking ‘do I look refreshed and hydrated’ rather than ‘am I actually hydrated and protected,’ and by taking this attitude, we’re simply not giving our skin the tools it needs to stay healthy.

We also have different facial products dedicated to the eye area, or often nothing is applied to the eye lids at all; leaving this delicate skin ready and waiting for free radicals to scavenge and destroy.

Lack of SPF in terms of volume

I think most people are amazed by how much SPF is needed in order for it to be effective. I would personally recommend nothing less than SPF 50+ and I’d also recommend some thorough research before you purchase. The higher the rating, the more potentially toxic sun filtering chemicals are used in the formula (if a traditional chemical formula that is). If you’re conscious of not covering your face with controversial ingredients and you’d rather avoid painful reactions, then I’d opt for a mineral based sunscreen that acts as an immediate physical barrier and is applied ‘after’ your skincare.

According to The Skin Cancer Foundation you should be using around 2 milligrams of SPF for every square centimetre of skin. Now I don’t know what everyone else gets up to in their spare time, but I don’t measure my own face and then get out the calculator to work out how many square centimetres it is, so….. what is a more helpful guide? There are two other, much easier ways to measure if you have the right level of protection.

  1. 1 teaspoon of sunscreen is sufficient for the face and front of neck (more is needed for the décolletage). Another ½ teaspoon for the front, top and back of ears, plus another ½ teaspoon for the back of your neck if required.


  1. Hold the palm of your hand out flat. Dispense sunscreen in a line down 3 fingers from base of palm to fingertip. Again, use more for the décolletage and back of neck.

Retinoid use

Retinoid use is another very easy way to damage your skin barrier. Unfortunately this can be done both knowingly and unknowlingly. Regarding the latter, there are many products on the market labelled as night-time use that don’t necessarily mention the words retinol or retinal on the front of the packaging or jar. It’s only when looking at the INCI list on the reverse or accompanying leaflet that retinol can be seen. Applying retinol without even knowing you’re doing it is a very speedy way of damaging the epidermis, firstly because you don’t even realise what’s about to happen to your skin, secondly because you don’t follow it with a rich moisturiser, and thirdly because you aren’t so fastidious about applying an SPF the following day – all of which really are a recipe for disaster. Please, please take care to read INCI lists and ask for advice if you don’t know what an ingredient is. Any skincare advisor worth their salt should be able to explain the ingredients in the products their selling, and at the very least, be able to pinpoint if a retinoid is included in the formula.

In terms of purposefully applying retinol as part of regular routine, we’re once again revisiting the topic of skin cell turnover acceleration. Skin can become incredibly dry, sensitive, red and sometimes even flake/peel, either for the first few months of retinol use, or if you have sensitive skin. For some people it’s obvious that retinol is intolerable for them by simply looking at their skin, but for others, you may not visibly notice the damage to the skin barrier that’s taking place.

So, the first step to healthy skin is to really know exactly what you’re applying to your face, both day and night, to avoid compromising the structural integrity of your skin barrier. 

The second step kicks in if your skin is already damaged, or you suspect it’s damaged; then it’s a case of how to slug properly and which type of product to use.

Is sluggling with Vaseline a good idea?

Now I mentioned earlier that the traditional method of slugging is to use a petroleum-based product. You would remove make-up and cleanse, apply your chosen serum then moisturiser, then cover your face in Vaseline. This would sadly leave you resembling a prepped roast chicken, and leaving your pillowcase and sheets covered in a clear jelly like substance that subsequently stains! Joking aside, what you look like at this stage is not remotely important, but what your chosen slugging product is doing to your skin is absolutely of the utmost importance.

Petroleum based products are traditionally used as they’re occlusive, and their purpose is to trap moisture. Petroleum jelly became hugely popular after it was discovered by oil drillers that slathered the stuff all over their bodies to protect and soothe their skin from dryness and irritation. Several decades later, ‘petroleum’ is listed as a carcinogen in Europe as it contains poly aromatic hydrocarbons (PAH) and in its raw form is banned in Europe. ‘Petrolatum’ however is different. This ingredient (the main one in Vaseline) is described as a triple purified form of petroleum jelly, plus minerals and microcrystalline wax.

Let’s take a further look at the pros and cons of using this product to slug. Petrolatum is mineral oil. Chemically speaking, cosmetic grade mineral oil is a complex mixture of highly refined saturated hydrocarbons with C15-50 chain length. It is not merely a "by-product" but rather a specifically isolated part of petroleum that is very pure and inert. It is an emollient and moisturise working mainly by occlusivity. So far so good right? Occlusivity is one of the basic mechanisms of how Petrolatum works, and it means that mineral oil sits on top of the skin and hinders so-called trans-epidermal water loss, i.e water evaporating out of your skin. We absolutely want to protect trans-epidermal water loss to avoid de-hydration, but the pros of mineral oil can also be interpreted as cons. By not penetrating the skin but mostly just sitting on top of it, and not containing biologically active components like nice fatty acids and vitamins means that mineral oil does not "nourish" the skin in the way plant oils do. Mineral oil does not give the skin any extra goodness, it is simply a film layer that works mainly by occlusivity. 

Another downside of using Vaseline is that you can trap dead skin cells, oil and debris, plus encourage bacterial overgrowth. It claims to be non-comedogenic, however anything that ‘physically seals’ the skin as adeptly as Vaseline will not allow your skin to breathe or desquam (turnover) on a normal schedule. If applied to a wet or damp face as normally recommended, it can also trap unwanted bacteria, and therefore Vaseline is an absolute ‘no no’ for acne sufferers.  

The very mechanism of Vaseline is that it sits on the surface. By doing so, it disrupts the self-regulation of the skin in terms of hydration, in other words, giving a false representation of the skin’s condition. This can result in drier skin – the total opposite of the intention of slugging.

So at a very quick glance Vaseline may seem like a good idea, but when you look closely, it’s a very primitive mechanism, and not one without downsides and restrictions.

When you look even closer, it presents more serious problems.

The INCI list for ‘Vaseline Original’ sold in the UK states the sole ingredient as follows: Petrolatum. When you look at the INCI list for ‘Vaseline Petroleum Jelly Original’ – also sold in the UK, it includes Petrolatum, BHT, and Tocopheryl Acetate; and when you look at ‘Vaseline Blue Seal Baby Soft’ it amazingly includes Parfum. BHT (Butylated Hydroxytoluene) is a somewhat controversial synthetic antioxidant that is used to preserve products. It’s a possible carcinogen and endocrine disruptor, meaning it can alter the normal function of your hormones and lead to disease. BHA is banned for use in food and beverages by the United Kingdom, European Union, Japan, and other countries. This is the time to ask yourself, ‘do I really want to risk leaving this on my face overnight?’

Parfum is another controversial ingredient. A synthetic aroma inclusion in many skincare products. The jury is out on this particular ingredient namely because it can contain on average 30-50 unlisted ingredients. I repeat, 30-50 (and up to 200) withheld ingredients that do not legally have to be listed on the INCI list of your product. This can include parabens, phthalates, dyes and solvents to name a few. The potential side-effects of these ingredients can include: dermatitis, itching, hives and allergic reactions. If parabens are part of the mythical parfum mixture, then we can add in endocrine disruption too, so if you’re someone that likes to know what you’re putting onto and into your body, parfum is not your best friend.

There must be a better way?

If you’re going to slug, would you rather use the Vaseline method above, or a totally natural product that not only wins first prize in terms of occlusive functionality, but also tackles bacteria, hugely increases hydration, restores the skin barrier, and its active ingredient is clinically proven to deliver serious results in tandem?

I think the research speaks for itself so I’m going to go out on a limb and re-name the trend. We’re not going to ‘slug’ the skin anymore, we’re going to ‘bio-force’ it. Bearing in mind the key objectives here are to a) protect and reinforce the skin barrier and b) ensure a variety of essential natural nutrients needed for protection and regeneration are delivered to the skin cells toute-suite!

If you can do this in the secure knowledge that the active ingredient you’re using is clinically proven to do the following – it’s a win win situation:

  • Has antioxidant activity (anti-ageing power) 60x stronger than resveratrol and a-tocopherol
  • Reduces the depth of lines and wrinkles by 20% in 12 weeks, and reduces acne by 58% in just 6 weeks
  • Significantly improves elasticity and firms skin
  • Significantly reduces hyperpigmentation

You may know which product I’m talking about, and it’s our triple award-winning Limitless Facial Balm. Let’s look at this product’s bio-forcing functionality first and foremost, including its occlusive properties. One of the reasons this product works so incredibly well for decreasing transdermal water loss is because it contains a large percentage of lovely, luscious, skin adoring botanical butters. Butters are some of the most hardworking skincare ingredients around, and mango butter in particular is brimming with antioxidants, vitamins and minerals that far exceed the moisturising and barrier-boosting abilities of other better-known butters (shea or coco).

So what exactly does mango butter do?

  • Super Hydrator: Thanks to its butter-like texture mango butter is a powerful emollient for dry skin, forming a naturally occlusive, protective barrier that helps to boost skin’s own natural barrier function. 
  • Helps Fight Fine Lines, Wrinkles and Sun Damage: Mango butter is stacked with antioxidants, vitamins, and minerals that set it up with some pretty potent anti-aging properties. A high percentage of tocopherols (vitamin E) can help fight environmental stressors like UV rays, pollution, and even visible light. Vitamin A can help decrease sun-related skin damage, and phytosterols which are natural skin-loving compounds similar to cholesterol help support a healthy skin barrier.
  • Protects skin: Mango butter contains triterpenes, which are plant compounds that have anti-inflammatory, antiviral, and antimicrobial properties that can help protect skin and aid in the repair of dry, irritated, and generally upset skin. 
  • Helps Support Collagen Health: This nutrient-rich butter contains a large amount of vitamin C, which can help improve the production of collagen—the primary structural protein in skin and connective tissues. 

The beauty of this butter (and our balm is full of it), is that it melts easily on contact with the skin and therefore absorbs quickly, so even if you’re using it at night as a bio-forcing mechanism, it’s not going to ruin your bed linen, and it’s secretly going to work on a) providing that occlusive, yet breathable layer and b) delivering intensely nourishing properties to your skin overnight.

The second superstar bio-forcing ingredient in the Limitless Balm is Jojoba Seed Oil. Jojoba has a very unique chemical structure. The skin’s sebum recognises the wax esters in Jojoba as its own and as a result is readily absorbed deep into your skin layers. It creates a thin, protective and breathable layer, that reinforces the protective barrier function (the desired endgame), and without the need for a thick, sticky, and somewhat controversial barrier. Jojoba is also an amazing anti-inflammatory which can work wonders for irritation, dryness and hormonal skin.

In addition to Mango butter and Jojoba Seed Oil there are a number of high performance botanical oils, extracts and actives that go into our balm that will transform a simple slugging routine into a full-blown restorative bio-force powerhouse. Sytenol ® A Bakuchiol (a bio retinol), Acai Berry Oil, Grapeseed Oil and Squalane are just a few.

How to bio-force effectively?

  1. Thoroughly cleanse, either with a water-based cleanser or, double cleanse by using a cleansing oil and hot cloth method followed by a water-based cleanser.
  2. Use a humectant-based skincare product on a damp face such as our Hyaluronic Acid based Limitless Facial Serum.
  3. Follow with a premium quality moisturiser such as our Limitless Facial Cream or our Limitless Facial Oil.
  4. Skip the moisturiser stage if you don’t have time, and apply your bio-force product straight after your humectant serum.

Until next time.....


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