Skin cycling, skin flooding and the rest of the viral routines
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The short answer
Does skin cycling work?
No trial has tested the four-night skin cycling rota itself. The idea underneath it is sound: retinoids and exfoliating acids irritate less when they are spaced out and skin gets nights off to recover.
Evidence: No good evidence How we grade evidence
Every year the internet names a routine and every year a lot of people buy things. The useful question is not whether the name is silly, it is whether the underlying idea holds up.
What is skin cycling, and is the idea behind it sound?
Skin cycling is a four-night rota: exfoliate one night, use a retinoid the next, then two nights of recovery with nothing but moisturiser. There is no trial showing the four-night version beats any other schedule, but the principle underneath it is sound and quite old. Mild irritation and stinging are the most common side effects of topical retinoids, and much of that irritation comes from using strong actives too often and too close together. Skin copes with them better when it gets time to recover. If a rota is what makes you stop piling acids on top of retinol, it is doing something useful.
What is skin flooding?
Skin flooding means applying a humectant to damp skin, then a moisturiser on top to seal the water in. This is just how humectants work: they draw water up into the outer layer of skin, and without something on top holding it there, it evaporates. Reasonable for dry or dehydrated skin. Pointless as a separate purchase, since it is a technique rather than a product.
What is slugging, and who is it for?
Slugging is a thin layer of petroleum jelly over your moisturiser at night, and it suits dry skin best. Petrolatum reduces water loss more effectively than almost anything else: a review of how moisturisers work reports it cuts water loss through the skin by more than 98%. Genuinely good for dry, cracked or irritated skin, as our piece on the skin barrier explains. Not for congestion-prone skin, and not over active ingredients, since covering skin can increase how much of a product gets in, and with a retinoid or an acid that means more stinging.
Why do viral skincare routines keep getting new names?
Viral routines keep getting new names because a name is easier to sell than a principle, and the principles underneath change slowly. Skin cycling, flooding and slugging are old advice about spacing out actives, sealing in water and protecting dry skin, repackaged for a feed. The useful habit is to ignore the name and look for the idea, which usually costs nothing.
How can you tell if a viral skincare routine is worth trying?
A viral skincare routine is worth trying only if it passes three simple questions. Does it require a product you do not already own? Does the explanation involve a mechanism that can be described in one plain sentence? And would it still make sense if it had a boring name? Most viral routines survive the first two and fail the third, which tells you the name was the product. If you would rather skip the trends altogether, a MyAgenix read builds a routine around the steps with evidence behind them.
Questions people ask
Can you use retinol and an exfoliating acid on the same night?
You can, but it raises the chance of irritation, especially if you are new to either. Most people find alternate nights easier to tolerate, and many do not need an exfoliating acid at all once they use a retinoid regularly.
Is skin cycling suitable for sensitive skin?
The rest nights help, but sensitive skin often does not tolerate both an exfoliating acid and a retinoid in the same week. Start with one active on a couple of nights a week, and build up only if your skin stays comfortable.
Can you slug over retinol?
It is best not to. Covering a retinoid or an acid with petroleum jelly can increase how much of it gets into the skin, which usually means more stinging and redness. Save slugging for nights when you use only a moisturiser.
Do you need special products for skin flooding?
No. Skin flooding is a technique rather than a product. Any humectant serum or toner, such as one with glycerin or hyaluronic acid, applied to damp skin and followed by your usual moisturiser does the job.
Sources
- Mild irritation and stinging are the most common side effects of topical retinoids (nhs.uk)
- they draw water up into the outer layer of skin (pubmed.ncbi.nlm.nih.gov)
- a review of how moisturisers work (pmc.ncbi.nlm.nih.gov)
- covering skin can increase how much of a product gets in (pubmed.ncbi.nlm.nih.gov)
General information about skin, not medical advice. MyAgenix offers cosmetic guidance to help you choose products. It does not diagnose or treat any condition. For anything that needs treating, see a pharmacist, your GP or a dermatologist.