Choosing the best shampoo is hard. Walk down any aisle at the supermarket and you’ll see shampoos for normal hair, dry hair, and oily hair. There are also sulfate-free, professional, and medicated shampoos. With so many choices it can be difficult to figure out which shampoo to use to make sure your hair looks the best.
How Does Hair Shampoo Work?
Shampoos work by removing the oils and dead skin out of your hair and scalp. Detergents are the ingredients in the shampoo that do that. One end of the detergent molecule is non-polar so that it attracts non-polar oils. The other end of the detergent molecule is charged so that water can rinse the detergent-oil complex away. Your dishwashing soap and laundry detergent works in the same way.
Sulfate Containing Shampoos
One of the most commonly used detergents in shampoos is Sodium Lauryl Sulfate (SLS). It is a harsh detergent and can strip the natural oils from the hair and skin. Most of the shampoos found in supermarkets will contain sulfates. An alternative is Sodium laureth sulfate (or sodium lauryl ether sulfate, also known as SLES). It cleanses hair effectively without irritating the skin.
Salon and professional formulated shampoos and conditioners often have a different formulation of ingredients than products bought in the supermarket. They tend to be more expensive and are more likely to be free of sulfate detergents. Some professional shampoos are concentrated and must be diluted prior to use. Others are used for specific purposes like maximizing the uptake of hair dyes during hair treatment procedures.
Medicated Hair Shampoo
Medicated shampoos are designed to treat scalp conditions as well as to cleanse your hair. The most common medicated shampoos are used to treat itchiness and scaling on the scalp. Others contain the chemical ketoconazole, which is an anti-fungal design to treat scalp conditions such as seborrheic dermatitis,1 which causes scaly red patches on the scalp and dandruff.
The most common scalp conditions include:
- Dandruff/Seborrheic Dermatitis: This happens when dead skin cells build up on the scalp causing flaky, scaly patches. It can be controlled with shampoos that contain active ingredients such as zinc pyrithione or salicylic acid2
- Scalp Psoriasis: This itchy skin condition causes red scaly patches on the scalp and may lead to patchy hair loss. Medicated shampoos containing coal tar or the antifungal ketoconazole can help control flare-ups of this scalp condition.
- Ringworm: This is a common fungal infection which causes scaly rings and patchy hair loss. Fortunately, it is easily managed with an anti-fungal shampoo containing selenium sulfide.3
Dandruff is actually caused by Malassezia globosa.4 These fungal organisms feed on dead skin cells and the oils secreted by hair follicles and can actually impede hair growth. One study found that using anti-fungal ketoconazole shampoo alongside finasteride improved androgenetic alopecia (or male pattern baldness) more than using finasteride alone.5
The Right Shampoo for Different Hair Types
Not all shampoos are created equal. Basically, a shampoo serves the purpose of cleansing the hair and scalp, but many shampoos contain specific treatments designed to condition and enhance different hair types. It’s good to know a little about the types of hair and which shampoo is right for each so that you can choose the right one for your hair.
Regardless of your hair type, we recommend using a shampoo that does not contain sulfates as it is irritating to the hair follicles and scalp.
Normal Hair Shampoo
This type of shampoo is for you if you don’t need a special treatment for your hair. A regular shampoo, such as a generic brand you would buy in the supermarket, is best suited for people who have hair that is neither oily nor dry. It’s not for you if you have colored or permed hair, or if your hair is heat damaged because it won’t help to improve these conditions.
Oily Hair Shampoo
You would think that if you have oily hair you should use the strongest shampoo available and avoid conditioning but this is not the case. Doing so will leave your hair feeling dry and dull. Your scalp and hair follicles will then sense the dryness and shift oil production into overdrive to compensate. The best practice is to use a shampoo that describes itself as balancing, volumizing, or light. Follow up with a conditioner that contains good carrier oils like argan, coconut, avocado, or jojoba. These oils will nourish your hair follicles and leave it looking beautiful. The hair follicles will sense the moisture and stop producing as much oil as before. We recommend using jojoba oil because it best mimics normal human oils.
Clarifying/Deep Cleansing Shampoo
Clarifying or deep cleansing shampoos7 are beneficial if you tend to use a lot of hair styling products between washes. A clarifying shampoo will remove residue left behind from hairspray, hair gel, and dry shampoo. It uses stronger detergents to cleanse the hair. And because the detergent used is stronger you should only use this type of shampoo once or twice a month, because frequent use can strip the natural oils from your hair.
How Often to Wash Your Hair
Keeping your hair thick, healthy, and shiny is not just about finding the right shampoo and conditioner for your hair type. It’s also about when and how you wash your hair. How often you wash will depend on the type of hair. But you should never need to wash your hair on a daily basis.8 Usually, every three days or so should suffice.
When you've finished washing and conditioning, don’t be too hasty to reach for the towel. Wrapping wet hair in a towel or turban can cause your hair to break or pull out at the roots. It’s okay to pat your hair dry with a towel, then let it air dry naturally. If you really must use a hair dryer, keep it on a cool setting, and don’t over-dry your hair.
Regardless of what shampoo you use and how you use it, conditioning after you shampoo is important because while shampoos cleanse dirt and residue from the hair, they also remove oils. A quality conditioner can restore the hair’s natural balance of oils. Remember, if you are using a 2-in-1 conditioner, typically the conditioning agent will be silicone rather than an oil. For this reason, it’s better to use a separate conditioner after a 2-in-1. The most effective conditioners contain carrier oils such as argan, avocado, coconut, or jojoba oil which restore the hair’s natural moisture.
Determining your hair type and hair routine will help you discover what type of shampoo and conditioner may be best suited for your hair. Discover other tips for hair care, and find out more about natural hair care and how your diet affects hair growth here.