Understanding the Types of Shampoos Available

Shampoos are a staple in personal care, essential for maintaining clean and healthy hair. However, the variety of shampoos available in the market can be quite overwhelming. Choosing the right shampoo depends in part on understanding the shampoo ingredients and their effects on different hair types. This article explores the more common types of shampoos available at most local pharmacies and supermarkets, particularly focusing on their detergent content and their suitability for different hair conditions.

Sodium and Ammonium Lauryl Sulfates: Harsh detergent shampoos are often characterized by the presence of sodium lauryl sulfate or ammonium lauryl sulfate in the ingredients list. These sulfates are potent cleansing agents known for their effectiveness in removing dirt and oil from hair.

Sodium lauryl sulfate (SLS) and ammonium lauryl sulfate (ALS) are commonly found in many shampoos due to their cost-effectiveness (i.e. they are cheap to make!). They produce a rich lather and are highly efficient at cleaning. Whilst these deterents are strong and harsh to the hair, they are still useful to some people. They can be popular choices for individuals with oily hair, for people who work in dirty and sweaty jobs where robust hair cleaning products are needed, and/or for those for who do not wash their hair frequently.

However, the strong cleansing action of SLS and ALS can strip the hair of all of its natural oils, leading to dryness and skin irritation, especially for those with sensitive scalps or dry, curly hair. The natural oils in curly hair do not distribute evenly along the hair shaft, and the hair fibers have thinner cuticles on the outside curve which are easier to damage and breakdown. This make harsh detergents particularly unsuitable for curly haired people as they can exacerbate dryness and frizz.

Laureth Sulfates: Sodium laureth sulfate (note the “eth” in “laureth” when looking through the ingredients list to differentiate it from “lauryl” sulfates) is another common ingredient in many modern shampoos. It is a somewhat milder alternative to lauryl sulfates. It is less irritating to scalp skin and still leaves the hair shiny. It is becoming a more popular detergent in many general purpose shampoos as people become more aware of the problems with lauryl sulfate-based shampoos.

However, it is relatively more expensive to manufacture and consequently, shampoos with laureth sulfate detergents tend to be a bit more expensive. Despite being milder, laureth sulfate-based shampoo can still be too harsh for some individuals, particularly those with very curly hair, dry hair, or those who wash their hair on a daily basis.

Triethanolamine (TEA) and Monoethanolamine (MEA) Salts: For those with sensitive scalps or damaged hair, milder detergent shampoos are often more appropriate. These shampoos typically contain triethanolamine (TEA) or monoethanolamine (MEA) salts of alkyl sulfates.

TEA and MEA salts are much gentler in their detergent action compared to lauryl sulfates and laureth sulfates. Shampoos containing these ingredients are suitable for individuals with dry or damaged hair, as they cleanse without excessively stripping natural oils away. When choosing a shampoo, checking the ingredient list for TEA or MEA can help in selecting a product that provides the right balance of cleansing and mildness.

Note, however, that as they are milder they are less effective in removing dirt and oils. For those who have very oily hair, or work in dirty environments and need a lot of cleaning power in their shampoos, TEA and MEA-based shampoos may not be strong enough to do the job.

Nonionic Surfactants: The mildest shampoos typically contain nonionic or amphoteric surfactants. These ingredients are known for their gentle cleansing properties and are often found in baby shampoos and products for sensitive scalps.

Nonionic surfactants do not carry an electrical chemical charge, which makes them less likely to cause irritation. Common nonionic surfactants include sorbitol esters, tweens (e.g., tween-20, tween-80), and polyglyceryl ethers. These ingredients provide very mild cleansing, making them suitable for individuals with very low oil production or those who need gentle care due to scalp sensitivity.

Amphoteric Surfactants: Amphoteric surfactants can carry both positive and negative charges, depending on the pH of the solution. Examples include betaines, alkyl imidazolines, and alkyl amino acids. These surfactants are also very mild and are commonly used in baby shampoos. They provide a gentle cleansing action, making them ideal for people with sensitive skin or those who do not require strong detergents to clean their hair.

Soap based shampoos: In addition to synthetic detergent-based shampoos, there are also soap-based shampoos that appeal to those seeking more natural hair care options. Soap-based shampoos are formulated using traditional saponification processes, where natural oils or fats are reacted with an alkali, typically sodium hydroxide (lye), to produce soap. Soap based shampoos were the only option before detergent shampoos became prevalent from the 1960s onwards. While these shampoos are made from natural ingredients and generally milder, they do have their own problems, particularly for people in “hard” water areas, where soap shampoos interact with salts in the water and can leave residue on the hair fiber.

Selecting the Right Shampoo: Choosing the right shampoo involves considering the specific needs of your hair and scalp. Here are some basic guidelines to help make an informed decision:

1. Hair Type and Condition:
   • For normal to oily hair, shampoos with lauryl sulfates (SLS or ALS) might be suitable due to their strong cleansing action. But be aware that they will remove pretty much all of the natural oils. Combining their use with using a good conditioner after shampooing can help mitigate this problem.
   • For dry, heavily processed, or damaged hair, shampoos with milder detergents like TEA or MEA salts are preferable. The hair is already damaged and it is easy for detergents to get inside into the hair cortex. Harsh detergents can then break the disulphide bonds of keratins in the hair shafts leading to even more damage and weakness. Milder shampoos still get inside damaged hair, but they are less able to break up the disulphide bonds that give hair its strength.
   • For sensitive scalps or people with very dry hair, look for shampoos with nonionic or amphoteric surfactants for their gentle cleansing properties. Be aware that they won’t be very effective at removing lots of oil or dirt.
2. Frequency of Washing:
   • Individuals who wash their hair frequently may benefit from using milder shampoos to avoid over-stripping natural oils. Leaving some natural oils behind after shampooing reduces the “dry” straw-like feeling of hair with harsh shampoos.
   • Those who wash their hair less often might need stronger detergents to effectively remove accumulated dirt and oil. If this is the case, look into using a good conditioner as a separate product to apply after shampooing. Also consider oil treatments on an occasional basis.
3. Scalp Sensitivity:
   • If you have a sensitive scalp, opt for shampoos labeled as hypoallergenic or formulated for sensitive skin. These often contain gentler surfactants and fewer irritating ingredients. There are also medicated shampoos available, sometimes these are only available from the pharmacist, so ask for their advice and what they have.
4. Environmental Exposure:
   • If your hair is frequently exposed to pollutants or styling products, you may need a shampoo with stronger cleansing agents to thoroughly clean your hair. You might need to wash more regularly, or repeat the shampoo application process, to get dirty hair clean. Investing in a separate quality conditioner will help make hair feel less dry.

Experimentation and Personalization: Finding the perfect shampoo often requires some experimentation. Hair care is highly individual, and what works for one person may not work for another. Start with a product that seems appropriate for your hair type and condition, and adjust based on your hair’s response.

Conclusion: Understanding the different types of shampoos available can significantly impact the health and appearance of your hair. Harsh detergents like sodium and ammonium lauryl sulfates are suitable for thorough cleansing but can be too drying for some hair types. Milder detergents, such as TEA and MEA salts, offer a gentler alternative for dry or damaged hair, while nonionic and amphoteric surfactants provide the mildest cleansing, ideal for sensitive scalps and delicate hair. By carefully selecting a shampoo based on your hair’s needs and experimenting with different formulations, you can maintain healthy, beautiful hair.

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