What causes greasy hair

Greasy hair is frustrating; it can feel like you have to plan your whole social calendar around washing your hair. Not being able to go out on hair non wash day because you’re desperate for a shampoo session is a very real thing!

Generally speaking, the finer your hair is, the quicker grease will build up as there’s less hair to absorb the natural oils produced by your scalp. But if you’ve ever wondered: “what causes greasy hair in the first place?” as you navigate this natural process, we’re here to clear the fog and help you understand why your hair gets greasy.

What causes greasy hair

A brief guide to greasy hair causes

Few things are more frustrating than investing the time in washing your hair, enjoying that clean, free flowing feeling, only for it to last for less than a day. So annoying!

Why does my hair get greasy so fast, we hear you ask? A number of factors come in to play here – keep reading to learn more about them.

Your scalp naturally produces a substance called sebum, natural oils that help support the health of your hair and protect it from the outside. Sebum also helps to keep your hair’s moisture at the optimum healthy level. Over time, this substance can build up, leaving you with that heavy, sticky haired look within a couple of days of washing your hair.

There are a few things that can exacerbate the production of oil on the scalp, like physical activity, changes in the weather or hormones (keep scrolling for more details).


Significant life events such as pregnancy, giving birth, puberty and menopause all see a shift in hormones, which can have a knock-on effect on the oiliness of your scalp. If you’re worried about any of the conditions above or an underlying factor that could be contributing to greasy hair, always speak with your doctor.

Changes to environmental conditions

A sudden drop or increase in temperatures, or even a complete change of climate may see your body react by increasing its production of sebum to protect your scalp and hair. This overcompensation is to help support your hair through harsh conditions – even if it may not be the finish you want for your hair!

This doesn’t just relate to the weather outside! During winter, when we go from the cold outside to the heated indoors, this change in temperature can cause our body to react and you might notice your hair becomes a little greasier quicker during the winter months.


Whether it’s a sunhat in summer or a beanie in the colder months, wearing head gear’s likely to spur greasiness on the scalp. Why? Because you’re trapping the natural oils your scalp produces (and adding additional heat to the environment), while pushing hair toward the scalp, increase the chance of oiliness spreading. Hats also flatten the hair, making the appearance of oil more obvious.

Using too much of an oil-based or conditioning product

If you’ve reached for the hair oil as a solution to dry strands, it’s important to keep the oil application away from your scalp. Stick to the tips to mid-lengths of hair to avoid the oily look.

Equally, using too much conditioning agent, particularly if you’re applying to the roots, can cause a greasy aftereffect.

Top tip: Avoid the roots if you’re using deep conditioner treatments or oils to avoid the look of oily strands or hair that’s weighed down. Not sure if you’re using the right treatment for your hair type? We’ve put together a little guide to help!

Using the wrong shampoo for your hair type

If you’re struggling with greasy hair, it’s worth assessing the shampoo you’re using. If it’s a moisturising shampoo, this probably isn’t helping the situation. Greasy hair needs a cleansing shampoo that helps to remove dirt, oil and product build-up. A clarifying shampoo is the perfect solution.

Not only do clarifying shampoos remove build-up of excess oil from your scalp, they eliminate any product build-up, pollution and other dirt too. For squeaky clean hair that’s completely refreshed, use our Micellar Cleanse & Nourish Shampoo. It offers a deep clean without being harsh on your hair, so you can rest easy that all excess substances are gone from your scalp.

Top tip: Turn down the temperature of the water in-shower, as hot water stimulates your sebaceous glands, leading to

Washing your hair everyday

When your hair gets greasy easily, it feels like the easiest solution is to wash your hair daily to keep those sebum levels down. But this is actually making the situation worse! By regularly stripping your hair of its natural oils, your hair thinks it needs to replenish these more frequently. Gradually cut down to 2-3 times a week if you can – ease into it by replacing every other wash with a water-only rinse. When you do wash your hair, be sure to only apply conditioner towards the ends to keep your scalp and roots free of weighty substances. Dry shampoo is really helpful here: look for those with loose powders that can be spread through your hair evenly and mop up excess oil.

Touching or playing with your hair

We all love running a hand through freshly washed hair, but touching your hair or rubbing your scalp may actually encourage your scalp to increase its sebum production. By running your hand through your hair, you’re also moving the sebum around your hair, which will add to the greasy appearance. If this sounds familiar, experiment with a fresh style that’ll prevent you from touching hair with hand, like pinning or tying your hair back so it’s away from your face.

Dirty brushes and styling tools

Always use clean tools – brushes, combs, heat styling tools – to minimise contact with grease and other oily substances, and change your pillowcase regularly to give your hair a clean environment at night time.

Similarly, be mindful of how often you brush your hair when it’s oily, as brushing helps spread sebum through your hair. If your hair is dry, go ahead and brush regularly, but if it’s oily brush an absolute maximum of 3 times a day. Brushes made with natural boar bristles are much gentler on the hair.

Now that you’re a bit more clued up on the different causes of hair, you’ll be better equipped to tackle greasy hair days with ease. Remember that it’s a completely natural process, but with our simple steps you’ll be able to ensure greasy hair doesn’t rule your routine.

Everyone gets greasy hair (it’s natural!) but if you’ve noticed your hair has rapidly become greasy when it wasn’t before, read our guide to suddenly greasy hair to find out what could be causing this change and our guides on how to care for greasy hair and managing greasy roots and dry ends. Here’s to great hair days, every day!