How to Keep Hair From Getting Greasy
To keep your hair from getting greasy, limit how often you wash it to 2-3 times a week since overwashing your hair can cause it to produce more grease. When you do wash your hair, only condition the ends so you're not making the roots of your hair greasy. Also, wash your hair with a clarifying shampoo once a week, which will make your scalp less oily. You can also prevent grease by brushing your hair less frequently since brushing causes the oils on your scalp to spread to the rest of your hair.
Don’t wash your hair every day. Washing the grease from your hair may seem like the best solution at first, but daily washing actually causes your hair to produce more grease. Your hair tries to make up for the natural oils you're washing out each day, causing a cycle of increased grease. Wash your hair only 2 to 3 times per week maximum for the best results. Wear a shower cap on days that you don’t shampoo. Getting your hair wet without washing also causes natural oils to be stripped away and causes your hair to overcompensate in grease. To protect your hair from getting wet in the shower, secure it inside a shower cap. Apply conditioner to your ends only. Hair that's prone to grease doesn't need more conditioning near the roots, it needs less. However, not conditioning your hair at all can cause your ends to get dry and damaged-looking. When you use conditioner after shampooing, apply it starting halfway down your hair and go all the way to your ends. Be sure to always rinse conditioner thoroughly from your hair, or use a leave-in conditioner. On days that you're not shampooing, you can get rid of style creases or cowlicks by rinsing the creased parts of your hair and applying conditioner there as well. Use cool or lukewarm water when washing your hair. Hot water opens the cuticle of your hair and strips more natural oils from your hair. Hot water also causes your pores, including the ones on your scalp, to produce more sebum, or thick oil. This thick oil will start traveling down your hair strands from your scalp as soon as you leave your hot shower. For the best results, keep your shower water as cool as you can, especially when rinsing shampoo and conditioner from your hair. Cool water closes the cuticle of your hair, which will help to keep moisture in. Use a coin-sized amount of shampoo. Using too much shampoo with each wash can lead to build-up and make your hair look heavy and greasy. When squirting shampoo into your hand to use, make sure you use no more than a large coin amount, like a quarter or two-pence piece. You may need more or less depending on the length and thickness of your hair. If you accidently squirt too much shampoo into your hand, remove some of it before starting to apply shampoo to your hair. Try a dry shampoo between regular shampoos. Dry shampoo, not to be confused with shampoo for dry hair, is a powder that many people use between regular shampoos to reduce grease, build volume, and refresh their hair. You can buy spray versions or ones that come in a shake container. Apply a few squirts or shakes to your roots if your hair is looking greasy, and rub it around on your scalp to absorb the oil and achieve a matte finish at your roots. If you have dark hair, be sure to buy invisible dry shampoo so that you avoid getting a greyish tint at your roots from the white powder. Use a “purifying” or “clarifying” shampoo once a week. Your greasy hair may actually be coming from a greasy scalp, which can be remedied with a shampoo labeled purifying or clarifying. Choose a day of the week to use this type of shampoo, and on the other day that you wash your hair, use your normal shampoo that you like for your hair type. If you like using matching shampoo and conditioner products, these shampoos do sometimes have an accompanying conditioner to go with them. You can use a purifying or clarifying conditioner for your ends, or your usual conditioner, on days that you use the purifying shampoo. However, keep in mind that clarifying shampoos tend to dry out your hair, so you may need a deep conditioner to restore the moisture. Avoid products for dry or damaged hair. Shampoos and conditioners that are designed for dry or damaged hair may leave a thin film on hair to seal in moisture and protect it from further damage. While this is good for hair that is actually dry or damaged, all it does to hair that's prone to oiliness is add more weight to the hair and make it look greasier. Avoid “smoothing” or “gloss” products. Similar to products for dry or damaged hair, shampoos, conditioners, gels, serums, or sprays that are for smoothing or gloss add an extra sealant layer of product on top of the hair. Hair that's prone to greasiness needs less smoothness, shine, and gloss, not more. To use hairsprays and serums on hair that's prone to greasiness, look for volumizing or products labeled “lightweight” instead. Try oil-absorbing sheets in grease emergencies. The oil-absorbing sheets that you can buy for your skin also work well on greasy hair. These thin paper sheets blot out oil regardless of the source. Carry a packet of these sheets in your wallet or purse, and simply blot grease spots out of your hair when you're on the go. Eat a diet low in carbs and trans fats. Trans fats, like those found in many fried foods, vegetable shortening, cookies, crackers, margarine, chips, and baked goods, contribute to greasy hair and skin without providing any nutritious value to your body. Try to limit these foods entirely, and reduce the amount of saturated fats you consume through meat and dairy products. High carbohydrate, high sugar foods also cause your body to produce more sebum, or thick oil, on your skin – including your scalp and hair. Baked goods and foods high in processed white flour (white breads and pastas) should be replaced with whole grains, low-starch vegetables, legumes, and fruit. Continue eating sources of good fats, or foods with essential fatty acids such as nuts, seeds, fatty fish, and unrefined whole grains. These foods provide your body with fats that it needs, and deficiencies in these fats can actually have a negative impact on your skin and hair health. Touch your hair less frequently. Touching your hair transfers oils from your fingers and hands onto your hair. Try to touch your hair as little as possible when you're not styling it. If you need to fix your hair, use a clean brush or comb instead of your fingers. Avoid heat-drying as much as possible. Dry heat, much like hot water, tends to strip hair of its natural oil, causing it to overcompensate by producing even more oil. Allow your hair to air-dry after washing it as often as possible. If you must heat-dry your hair on occasion, make sure to use a heat protectant spray to avoid potential damage. Clean your hairbrush. Brushing takes grease from the scalp and moves it down the hair follicles, so you should take hair to clean your hairbrush regularly. Remove hair from your brush as often as possible. Clean your brush once a week by squirting a few drops of dish soap into it, adding water, and rubbing the ends of the bristles with the soap suds. Rinse all the soap from your brush and let it air-dry. Because brushing moves oil down your hair, you should also avoid overbrushing. Try to brush your hair only when it is tangled or when you are styling it for the day. 
Don’t wash your hair every day. Wear a shower cap on days that you don’t shampoo. Apply conditioner to your ends only. Use cool or lukewarm water when washing your hair. Use a coin-sized amount of shampoo. Try a dry shampoo between regular shampoos. Use a “purifying” or “clarifying” shampoo once a week. Avoid products for dry or damaged hair. Avoid “smoothing” or “gloss” products. Try oil-absorbing sheets in grease emergencies. Eat a diet low in carbs and trans fats. Touch your hair less frequently. Avoid heat-drying as much as possible. Clean your hairbrush. 