Lesson one - oils prevent dehydration

Oil, as you will recall from school experiments, floats on water because it is less dense. Equally, if you cover something in oil water runs off it like, well, water off a duck's back because a duck's feathers are coated in natural oils. One way to prevent water penetrating a porous surface is to cover that surface with oil. That’s why oilcloths, for example, are great in the rain. 

Lesson two - oils smooth the way

Oils also make things smooth - they lubricate. Dry hair under a microscope is bumpy and full of cracks. Hair oils effectively smooth over the cracks in each hair follicle, like paint on a wall, and create a glossy finish. Your hair feels blissfully silky again and, when each hair follicle has a smoother surface, light bounces off it like a mirror; the more light that is reflected the more it catches your eye – hence, the high shine factor. 

Lesson three – biology

The body secretes a range of oils all the time. They keep our skin healthy and our hair happy. But not all of us produce enough natural oils – unlike our feathered friends in the pond – to keep our hair in tip-top condition. It might be because we're getting older and those cells responsible for producing oils are slowing down. But it could also be down to lifestyle. Hairdryers, heated styling tools, colour, sun, chlorine in swimming pools, general pollution and stress can have a dehydrating effect on hair.

Lesson four – nutrition

Can we top up with any old oil? Er, no. The oil you put in your car is a refined, man-made petrochemical and definitely not recommended for your hair. Try natural plant-based hair oils that your body will lap up. In the same way that what you eat is important, so is what you put on your hair. 

Lesson five – sensorial pleasures

Another reason not to use any old oil is fragrance. And that’s because not all oils smell particularly good, and you don't want to walk round stinking of beef dripping - you really don't. Luckily, there are many plant-based oils that smell amazing and take to hair like, well, ducks to water. 

Lesson six – which are the best oils?

Glad you asked. Top marks. There are a few that spring to mind: 

Coconut Oil

Ask yourself, why do Polynesian women have such gloriously shiny, healthy looking hair? They're surrounded by palm trees. Coconut Oil is brilliant for hair and for skin. You'll find it and its relatives Coconut Water and Coconut Milk in numerous ranges within the Ultimate Blends collection by Garnier. Coconut Oil also blends seamlessly with Cocoa Butter in the Sleek Restorer hair care range to help smooth and nourish dry, frizzy hair. 

Olive Oil

The gift that keeps on giving, it’s commonly used in Mediterranean countries as a body and hair conditioner. You'll find Virgin Olive Oil in Ultimate Blends Mythic Olive range for dry, brittle hair, which intensely nourishes dehydrated hair without weighing it down. This is important: if you simply comb Olive Oil straight into your hair you might find it weighs down your hair, leaving it lank and lifeless. It depends on your hair, but the scientists at Garnier spend a long time developing formulations that work for almost any hair type. 

Argan Oil

This precious elixir from Morocco, often referred to as 'liquid gold', is very good news for hair. Like olive oil and coconut oil, it's great for skin and has been used consistently for cooking for centuries. Packed with omega 6 and vitamin E, it helps to bring out your natural lustre. Ultimate Blends combine it with Camellia Oil in a range to help transform dry, dull hair, and with Cranberry Extract in a range to protect and illuminate coloured hair. There's also the Argan Richness range for very dry, unruly hair which blends Argan Oil with nourishing almond cream in a vegan formulation* that leaves hair shining like the Moroccan sun. *Vegan formula: no animal derived ingredients or by-products. 

Avocado Oil

Rich in vitamins B and E, Avocado Oil forms a potent blend with soothing shea butter, a plant-based oil from the African karite tree, in the Ultimate Blends Nourishing Repairer range - aimed at those of us with damaged hair. An intense moisture surge from root to tip will leave your hair super shiny and looking really healthy. It smells amazing too. 

Castor Oil

If your hair is extremely damaged, our Castor Oil range might be your saviour. Ultimate Blends teams Castor Oil with Canadian maple sap in the Intense Repairer range, also known as the 'Maple Healer'. Try it today for hair that feels stronger and less brittle. 

Lesson seven - specialist hair oils

As well as natural oils in shampoos, conditioners and masks, Ultimate Blends has created a range of paraben-free hair oils that can be applied directly to your tresses, after washing or between washes, to boost shine and shimmer. From the Blonde Illuminator Oil, with camomile and acacia honey, to bring out the best in blonde hair, to our Marvellous Glow Oil for dry, dull hair, blended with argan oil and camellia, we have the perfect hair oil for you. 

Is that clear? Great. Go to the top of the class!