Author: Jenna White | San Francisco Hairstylist
September 28th, 2021
September 28th, 2021
As a stylist, the most frequent question I get is “how often should I shampoo?”. My response always is "first and foremost, it's important to know how to shampoo properly so when you do, it counts". From how shampoo works to the most common ingredients, I answer all of your shampoo-related questions below.
How does shampoo work?
You can think of the active ingredient in shampoo as being within two categories: (1) non-detergents (soap) and (2) detergents. Non-detergents are made from natural ingredients, and act as an emulsifier for oil and water. This makes it easier to rinse impurities away when it's washed out. Detergents are synthetic, man-made chemicals with active agents (wetting agents) capable of lowering the surface tension of a liquid. These are known as surfactants, and they do this by having a hydrophilic "head" and a hydrophobic "tail", which essentially allows the shampoo to stick to oils and dirt in your hair. Those oils and dirt are then swept away when washed out. Another way to understand the difference between non-detergents and detergents: the former will leave a residue behind while the latter will not. Simplifying Hair Products II breaks down the purpose of other ingredients you'll find in shampoos to make them effective and pourable (i.e. the opposite of powered shampoos that are becoming more popular).
How often should I shampoo?
Some hair types will need to shampoo daily and others only need to wash once every ten days or so. Preference also plays a role here depending if you're trying to achieve a sleek look or a voluminous one. Shampooing less will condense your hair over time and allow it to hold more oils, which shampooing more will remove oils and promote a fuller look. Think about the following factors as you keep reading through this post, and check out Post-Workout Hair to learn more tips and tricks for managing your hair with a busy life.
Your hair's density
Your hair's condition/damage
The type of shampoo and conditioner you use
Your Scalp
Your scalp is an important part of figuring out how, and how much, to shampoo. This takes trial and error, plus may change over time. Generally, you should wash as often as your scalp can handle it because, like the rest of your skin, it is constantly shedding cells.
However, keep in mind that washing your hair has no effect on the amount of oil produced by your sebaceous glands. This depends on hormonal and genetic factors, and the glands have no way of responding to oils on the surface of your scalp. The theory that you could "train" your scalp to be less oily was disproven in 1982 by Kligman and Shelley.
If you're trying to avoid washing more frequently, then use a mixed boars bristle brush (BBB) to manipulate the scalp and softly remove cell build up. The Reddit page No-Poo/Natural Hair is a good resource for advice on maintaining your scalp when shampooing less frequently.
Your hair's density
- Fine: Needs to be washed daily, particularly if you have skin that is more oily. People with this hair type often feel that their hair looks too flat if they try to style it without washing and drying it first.
- Thick: Can be washed anywhere from once every three days to once every ten days. People with this hair type often feel that their hair looks too voluminous or puffy if they wash too frequently. Thick hair also takes longer to blow dry and style, making it a nightmare to wash daily because of the amount of time it adds to your routine.
Your hair's condition/damage
- Fine: If your hair is breaking due to damage you should try to shampoo less - every other day to every three days. Giving your hair a break from washing and styling can help with mitigating damage. Use shampoos and conditioners that are moisturizing, even if they give a flatter look then you like.
- Thick: Damage to thicker hair shows more prominently because there is more of it. Straight hair will often appear to have many flyaways, while on curlier hair damage can be easier to hide. Since your styling routine is already longer because of how much hair you have, avoiding a full wash and blow dry (i.e. heat) for as long as possible can help with mitigating damage.
The type of shampoo and conditioner you use
- Fine: If you aren't worried about damage, look for a volumizing shampoo and conditioner for day-to-day use. Clarifying shampoos will help strip extra oil from your hair, but should only be used once a week alongside a shampoo made for daily use. Avoid clarifying shampoos if your hair is damaged.
- Thick: Look for moisturizing and hydrating shampoos to counteract your volume. Co-washes are also a great option for curlier hair, and can be used more frequently since they are a combination of shampoo and conditioner. They're a great option if you need to wash more because of your workout schedule or job.
Your Scalp
Your scalp is an important part of figuring out how, and how much, to shampoo. This takes trial and error, plus may change over time. Generally, you should wash as often as your scalp can handle it because, like the rest of your skin, it is constantly shedding cells.
However, keep in mind that washing your hair has no effect on the amount of oil produced by your sebaceous glands. This depends on hormonal and genetic factors, and the glands have no way of responding to oils on the surface of your scalp. The theory that you could "train" your scalp to be less oily was disproven in 1982 by Kligman and Shelley.
If you're trying to avoid washing more frequently, then use a mixed boars bristle brush (BBB) to manipulate the scalp and softly remove cell build up. The Reddit page No-Poo/Natural Hair is a good resource for advice on maintaining your scalp when shampooing less frequently.
- Signs you may be washing too much: a scalp that feels dry or tight
- Signs you may not be washing enough: excessive product/oil build up
What is the proper way to shampoo?
To help the shampoo work, emulsify it in your hands before applying. Start applying in at the back of your head, ending at the crown. Take around a minute to apply it. Similar to washing your hands, shampoo takes a few seconds to lift the oils and dirt.
To help the shampoo work, emulsify it in your hands before applying. Start applying in at the back of your head, ending at the crown. Take around a minute to apply it. Similar to washing your hands, shampoo takes a few seconds to lift the oils and dirt.
- When you're looking for volume: Pay attention to the sides and back of your head when shampooing and rinsing, as these areas are commonly missed. For thicker hair, consider washing (or rinsing) in two sections. If you've gone 3+ days without washing, shampooing twice also makes sense.
- When you're looking to smooth/leave natural oils behind: Generally, use a minimal amount of shampoo and rinse it out fairly quickly. Try conditioning your hair first, then shampooing and conditioning again. See the "volume" bullet above if you feel like you need a deep clean. This is helpful but not always necessary.
Shampoo Ingredients
Many people search for shampoo via the phrase "shampoo without chemicals". Technically, if the shampoo has water in it this will count as a chemical, so a better approach is to search for shampoos via ingredients. I've given you a list to consider below.
Shampoo Without Silicone
Soluble silicone formulas can be washed out with gentler shampoos and conditioners that don't contain surfactants, and are capable of achieving the same results as non-soluble silicones. Common names on the bottle include:
Shampoo Without Sulfate and SLS
As a rule of thumb, ingredients like Ammonium lauryl sulfate and Ammonium laureth sulfate tend to be easier on sensitive scalps than Sodium lauryl sulfate. To learn more about surfactants, check out Simplifying Hair Products II.
Shampoo Without Parabens
Most water based shampoos contain preservatives because without them they will eventually grow mold or bacteria. Parabens are a type of preservative that are commonly used in hair products. According to The FDA "scientists continue to review published studies on the safety of parabens. At this time, we do not have information showing that parabens, as they are used in cosmetics, have an effect on human health" (Source: FDA, Parabens in Cosmetics). They're usually easy to spot on the bottle because they end in the word "paraben". Common non-paraben preservatives are shown in the list below. To learn more about parabens, check out this article published by Cosmopolitan: Wait, What Actually Are Parabens and Should You Avoid Them?
Shampoo Without Salt
Sodium chloride is another name for salt. It's used in shampoo and conditioner mainly to make the consistency thicker. A trend of "salt shampoos" has also been seen, where the benefits include being used as a scrub for the scalp, plus being gentler on the environment. This has may have been influenced by the idea of adding salt or sea water to your current shampoo. I wouldn't recommend adding sea water to your shampoo, as this could potentially generate bacteria and mold in your products over time.
Many people search for shampoo via the phrase "shampoo without chemicals". Technically, if the shampoo has water in it this will count as a chemical, so a better approach is to search for shampoos via ingredients. I've given you a list to consider below.
Shampoo Without Silicone
Soluble silicone formulas can be washed out with gentler shampoos and conditioners that don't contain surfactants, and are capable of achieving the same results as non-soluble silicones. Common names on the bottle include:
- Non-soluble: Dimethicone, Cyclomethicone, Amodimethicone, Pheryl trimethicone, Ceteraryl methicone, Dimethiconol, Stearyl dimethicone, Amodimethicone (non-soluble when Trideceth-12 and Cetrimonium Chloride are absent)
- Soluble: Cyclomethicone, Dimethicone copolyol, Lauryl methicone copolyol, any silicone with PEG as a prefix
Shampoo Without Sulfate and SLS
As a rule of thumb, ingredients like Ammonium lauryl sulfate and Ammonium laureth sulfate tend to be easier on sensitive scalps than Sodium lauryl sulfate. To learn more about surfactants, check out Simplifying Hair Products II.
Shampoo Without Parabens
Most water based shampoos contain preservatives because without them they will eventually grow mold or bacteria. Parabens are a type of preservative that are commonly used in hair products. According to The FDA "scientists continue to review published studies on the safety of parabens. At this time, we do not have information showing that parabens, as they are used in cosmetics, have an effect on human health" (Source: FDA, Parabens in Cosmetics). They're usually easy to spot on the bottle because they end in the word "paraben". Common non-paraben preservatives are shown in the list below. To learn more about parabens, check out this article published by Cosmopolitan: Wait, What Actually Are Parabens and Should You Avoid Them?
Shampoo Without Salt
Sodium chloride is another name for salt. It's used in shampoo and conditioner mainly to make the consistency thicker. A trend of "salt shampoos" has also been seen, where the benefits include being used as a scrub for the scalp, plus being gentler on the environment. This has may have been influenced by the idea of adding salt or sea water to your current shampoo. I wouldn't recommend adding sea water to your shampoo, as this could potentially generate bacteria and mold in your products over time.
Shampoo/Ingredients For Hair Care Concerns
Hair Loss
For assisting with hair loss, there are DHT-blocking shampoos plus ones with ingredients that help with inflammation. Saw palmetto, also known as Serenoa, naturally lowers the conversion of testosterone into Dihydrotestosterone (DHT). DHT is a sex hormone that contributes to human developments such as body hair, but it can also make you lose your hair faster and earlier. If you're experiencing any type of hair loss, the first place to start is with a doctor. You don't want to try different shampoos only to later find out a doctor would have pointed you in a different direction.
Hair Growth
Shampoos with biotin are frequently marketed as being helpful for hair growth. It is also commonly added to shampoos claiming to reduce hair loss, but there is no evidence that it prevents this. Consuming foods rich in healthy vitamins and minerals will help with overall hair health.
Dry Scalp
Some contributing factors to a dry or itchy scalp can't be solved with a shampoo. However, certain ingredients can offer relief.
Naturally Grey Hair Turning Yellow
Use two types of shampoo: (1) a purple shampoo and (2) a moisturizing shampoo. Grey hair tends to pick up unwanted yellow tones from the environment, and purple shampoo will help combat these tones. The moisturizing shampoo helps prevent your hair from becoming too dry, which can be exacerbated by purple shampoo. Check out Purple Shampoo for more insight on your options for these products.
Hair Loss
For assisting with hair loss, there are DHT-blocking shampoos plus ones with ingredients that help with inflammation. Saw palmetto, also known as Serenoa, naturally lowers the conversion of testosterone into Dihydrotestosterone (DHT). DHT is a sex hormone that contributes to human developments such as body hair, but it can also make you lose your hair faster and earlier. If you're experiencing any type of hair loss, the first place to start is with a doctor. You don't want to try different shampoos only to later find out a doctor would have pointed you in a different direction.
Hair Growth
Shampoos with biotin are frequently marketed as being helpful for hair growth. It is also commonly added to shampoos claiming to reduce hair loss, but there is no evidence that it prevents this. Consuming foods rich in healthy vitamins and minerals will help with overall hair health.
Dry Scalp
Some contributing factors to a dry or itchy scalp can't be solved with a shampoo. However, certain ingredients can offer relief.
- Salicylic acid: This can be found in drug store shampoos advertising scalp health. It will help remove scalp cells causing dandruff while also moisturizing dry spots. Consider using it seasonally during dry winter months, or on a regular basis as needed.
- Selenium sulfide: Formulated to control more serious dandruff and seborrheic dermatitis of the scalp. It's also used to treat pityriasis versicolour, a common fungal infection that causes small patches of skin to become scaly and discoloured.
- Ketoconazole: An ingredient that provides the same benefits as Selenium sulfide.
- Tea Tree Oil: Studies have shown that tea tree oil effectively fights many types of bacteria, viruses and fungi. These shampoos tend to be very calming and cleansing.
Naturally Grey Hair Turning Yellow
Use two types of shampoo: (1) a purple shampoo and (2) a moisturizing shampoo. Grey hair tends to pick up unwanted yellow tones from the environment, and purple shampoo will help combat these tones. The moisturizing shampoo helps prevent your hair from becoming too dry, which can be exacerbated by purple shampoo. Check out Purple Shampoo for more insight on your options for these products.
Related blog posts:
Simplifying Hair Products
Simplifying Hair Products II
Applying Hair Products
Simplifying Hair Products
Simplifying Hair Products II
Applying Hair Products
