Slugging is the habit of sealing your face under a thin layer of something occlusive as the last step at night, so the water you put on your skin has nowhere to go until morning. Petroleum jelly is the classic slug. A tallow balm does the same job with a breathable film made of fatty acids your skin already uses, and it does it with a pea-size amount instead of a shining mask. Here is the method, a week-by-week routine to ease into it, who it suits, and the honest comparison with the jar of jelly under your sink.
What slugging does
Skin loses water to the air all night, every night. Dermatologists call it transepidermal water loss, and it climbs when the barrier is thin: winter air, over-washing, acids, retinoids, a cold, a long flight. An occlusive layer on top slows that loss to a crawl. Whatever moisture you applied underneath stays put, the outer layer stays plump, and you wake up with skin that looks like it slept better than you did.
The trick's the order of operations. An occlusive holds in what is under it and keeps out what is over it. Water first, then the seal. Seal a dry face and you've sealed in dryness.
Petroleum jelly vs a tallow balm
| Petroleum jelly | Tallow balm | |
|---|---|---|
| What it is | Refined petroleum hydrocarbons, one ingredient | Rendered suet fat blended with a few plant oils, five to nine ingredients |
| Occlusion | Strongest known; near-total seal | Moderate; a breathable film |
| What skin gets from it | Nothing; it is inert | Oleic, palmitic and stearic acids that overlap with skin's own lipids, plus trace vitamins |
| Feel by morning | Still there, shiny, on the pillowcase | Mostly absorbed, soft skin, dry pillow |
| Amount | A fingertip, spread thin | A pea, warmed and pressed |
| Best for | One spot that must be sealed hard | A whole face, most nights |
This is the whole case for tallow as a slugging alternative: a breathable, non-petroleum film that the skin can actually use. Neither one is wrong. Petroleum jelly is the stronger seal and the cheaper one, and when a dermatologist wants a single patch locked down, it remains the tool. A tallow balm trades a little occlusion for a film skin can use, one that's absorbed by morning without leaving a glaze on the pillow. For a face, every night, most people prefer the balm.
The method
1. Cleanse, and stop there. Slug nights are the nights to skip the strong actives entirely, no exceptions. Retinoids, glycolic and salicylic acids and high-strength vitamin C all get amplified under a seal, and amplified isn't what you want at 2 a.m.
2. Leave the skin damp. Pat with a towel and stop while the skin's still glistening. If you use a hydrating toner or a humectant serum (glycerin, hyaluronic acid), apply it now to skin that is still wet. This is the water you are about to lock in.
3. Warm a pea-size amount. Scoop a pea of balm and rub it between your fingertips until it turns to a clear film. Cold balm dragged across a face uses three times too much, and it drags.
4. Press, do not rub. Press the film onto the driest areas first, cheeks and around the mouth, then lightly over the rest. The face should look dewy rather than greased, and it wants two minutes before your head hits the pillow.
Morning is a rinse with water or your usual gentle cleanser. Skin that felt tight the night before usually feels soft and looks smoother, and that look tends to hold through the day.
Who it suits, and how often
Dry skin, winter skin, and barrier-stressed skin can slug nightly. Combination skin does well with two or three nights a week, cheeks only, leaving the T-zone bare. Very oily or actively breaking-out skin should skip it, or keep it to a small dry patch, since sealing an area that's already producing too much oil rarely helps. If you're on a prescription retinoid, ask your provider before layering anything over it; many people alternate nights instead.
Two more cases worth naming. Skin over a healed tattoo loves a slug every few nights, which keeps the color clear and the surface soft. And hands respond as well as faces do: a pea of balm, a pair of cotton gloves, and winter knuckles look human again inside a week.
A week-by-week slugging routine with tallow
Most people who quit slugging quit in week one, because they went nightly and full-face on day one and woke up feeling greased. Ease into it instead. Here's the slugging routine I'd hand a first-timer, and it's the same one I use when winter arrives and my own face starts complaining.
Week 1, two nights. Pick two nights with a gap between them, Tuesday and Saturday works. Cheeks and around the mouth only, nothing on the T-zone. No acids, no retinoid, no strong vitamin C on those nights. Take a photo in the same window light on the first morning, because you will not remember what your skin looked like in three weeks.
Week 2, three nights. If week one stayed calm, add a third night and extend to the chin and the forehead. Keep the nose bare if you run oily there. This is usually where the morning difference starts showing up: skin that feels soft on waking rather than tight.
Week 3, settle at your number. Dry, winter or barrier-stressed skin can go nightly here. Combination skin usually lands at three nights, cheeks only. Oily skin should stay at two, or keep slugging to a dry patch and leave the rest alone. There is no prize for a higher number.
Week 4, judge it. Working looks like this: less flaking around the nose, makeup sitting flatter, and skin that does not feel tight by mid-morning. Not working looks like congestion appearing only where you applied, or a film that is still there at breakfast. Pull the photo from week one and compare, then keep the nights that earned their place.
A month of that costs almost nothing in product. Two to seven peas a week out of a 2 oz jar barely moves the level, which is the quiet argument for a dense balm over a bottle you pump.
Which jar to slug with
For dry skin, Honey Glow is the slug we reach for first. Manuka honey is a humectant, so the jar pulls water in as well as holding it, and oat oil and squalane keep the film light. For reactive skin, Bare Silk Unscented is the plainest seal we make, five ingredients and no essential oils, and it's the pick for anyone who wants nothing scented anywhere near a pillow. For a face that flushes, Moonlight Calm was built as an evening balm for exactly this ritual. A pea a night from a 2 oz jar runs well past a month, and the 60-Day Skin Test means you can run the whole experiment above and still get the product price back if your skin disagrees.
If you take one thing from this: start with Honey Glow ($42) if your skin is dry, or Bare Silk Unscented ($34) if it's reactive. Sixty days on your skin; if it disagrees, we refund the product price.
Questions we hear
Will slugging with tallow break me out?
Tallow scores low to moderate on comedogenic scales, and a pea-size film is thin. Skin that breaks out easily should patch test on one cheek for a week first, and keep the T-zone bare. Sealing over active breakouts is the one thing to avoid with any occlusive. More on pores here.
Can I slug over my retinol or vitamin C?
Not on the same night. A seal amplifies whatever's underneath, and retinoids and acids under a seal are how people end up with a stinging, peeling week. Alternate nights instead. Bakuchiol is the gentle exception, which is why Velvet Face Renewal is built to be used as a night balm on its own.
How much should I use?
One pea for the whole face. If your skin looks shiny rather than dewy after pressing it in, you've used too much; blot with a tissue and use half next time.
Does it need a serum underneath?
No. Damp skin's enough. A humectant serum underneath gives the seal more water to hold, which helps very dry skin, and it is optional.
Is there a natural slugging alternative to petroleum jelly?
A tallow balm is the closest one. It seals like an occlusive but the film is fatty acids your skin already uses, so it absorbs by morning instead of sitting on the pillow. Shea and plant butters work too, a little lighter and a little less occlusive.
What about slugging in summer?
Move to two nights a week, cheeks only, and let the air conditioning decide the rest, since dry indoor air in July does the same thing to skin that January does.
Go deeper
The chemistry of why a tallow film holds water is in the fatty acids in a jar of tallow, in plain English. The everyday method for daytime use is in how to use a tallow balm, and the wider case is in beef tallow for skin: the complete guide. Choosing between a balm and the lotion you use now? Tallow vs traditional moisturizers runs the numbers, water content and all.
Brian is the founder of Craft Tallow, a small-batch tallow skincare line shipped from Cottonwood Heights, Utah, built on 100% grass-fed suet. Questions? Reply to any email from us; it lands with him.