Just like that odd paradox that dictates that dieters can actually gain weight by cutting calories, one of the strangest skincare contradictions is that oily skin actually benefits from more oil. How can this be? It seems so counter-intuitive – surely the last thing you’d want to do to a face that’s breaking out all over the place and shining with grease is put oil on it?

But it’s true. Fiona Brackenbury, Director of Education and Training at Decléor explains. “Naturally when we have oily skin we spend all our time wanting to rid the skin of the oil as we believe this may be causing the breakouts. The more oil we remove, the more the skin will produce as part of its way of protecting itself.” 

A-list facialist Sarah Chapman agrees. “It’s a common misconception that oils and oil-based cleansers aren’t suitable for those with oily skin. In the case of oil-based products, ‘like attracts like’ so topical oils can combine with the oil in your skin and absorb easily, working in harmony with your skin’s natural sebum. Oils can benefit an oily skin by helping to balance out the natural oil production. If you strip the skin with harsh products, your oil glands produce more oil to counteract the effect so an oily skin will actually end up with more issues whereas if you apply an oil your skin will self-regulate."

Oil-based cleansers like Sarah Chapman’s Ultimate Cleanse (£40, sarahchapman.net) slide in through the pores, dissolving and liquefying trapped sebum, dirt and general grub. They’re also easily removed, leaving the skin soft and clean without stripping it, so they’re good for dry and sensitive as well as oily skins.

But which oils are best to use, and which should you avoid? Sarah advises steering clear of sweet almond oil, which can clog the skin, while people are wary of mineral oil for its comedogenic effect. “Look for products containing melon oil which is really lightweight and jojoba oil, which is the closest to your natural sebum, enabling absorption and carrying oil-based actives deeper into your skin.”

Fiona adds. “Plant and vegetal oils carry amino acids, vitamins and minerals to the skin and work superficially, while essential oils are the most concentrated part of the plant and work to the deepest layer of the skin. When these are combined that's when you are able to make a real difference. We use a combination of the two in our face and body serums."

"an oily skin will actually end up with more issues whereas if you apply an oil your skin will self-regulate"

"We have an amazing serum (£44, decleor.co.uk) which is clinically proven to slow down oil production. The powerful combination of Ylang Ylang essential oil slows the oil gland down and works deeply where the oil glands are and the passion fruit works on the surface so the skin feels hydrated but not oily and no excess oil is produced."

Ok, so certain oils are good for oily skin, but how much are you meant to use, and when?  Proceed with caution – less is definitely more. Fiona says you only need three drops of Decléor’s facial oil under your moisturiser to see results and if you’re using a cleansing oil to take off make-up, stick to an amount the size of a 20p piece. 

Sarah advises taking a little extra time to really massage the oil into the skin to help increase the uptake of vital nutrients. “An oil should have sunk in within a minute or so leaving you feeling nourished not greasy, if it hasn’t you are probably using too much with your application.”

“Use a few drops of oil on top of a serum to help push the serum into the skin, and as a special facial treatment a few times a week (personally I think you should use it every night). Dehydrated and dry skin will benefit from applying twice a day to help rehydrate skin cells - apply a small amount in the morning, mixed in with your moisturiser and then on its own at night. If your skin is playing up and sensitive, choose ceramide-rich oils or botanical and omega-rich calming oils.

It doesn't hurt that the act of applying a beautifully-scented facial oil to your skin and gently massaging it in is about as therapeutic as bathroom beauty gets too. And because you do just need a few drops of oil for it to work its magic, one bottle will last a long time - so you can justify buying the best.