How useful is washing hair without shampoo?

The “No Poo” method (short for “No Shampoo”) consists of cleaning the hair with alternatives such as hair washing soap, lava clay, baking soda, vinegar rinses or water instead of shampoo. This should result in numerous benefits for hair and the environment. From a scientific point of view, this approach is more than questionable. On the one hand, shampoos today are high-tech products with 10-30 formulation ingredients and sometimes several years of development time. Furthermore, objective measurement methods for testing efficacy have long been developed by laboratories in the cosmetics industry. On the other hand, the shampoo treatment has specific goals, namely the removal of sebum and dirt (and thus the reduction of the number of germs on the scalp). The removed sebum is replaced by nourishing additives in the shampoo. The current propaganda of sulfate-, paraben- and silicone-free shampoos lacks any scientific basis. The environmental product safety of cosmetic preparations is guaranteed by law.

More and more beauty blogs are promoting a bizarre hair care trend: “No Poo” (short for “No Shampoo”) promises healthier and shinier hair. The method is essentially to stop cleaning the hair with shampoo, instead using alternatives such as hair washing soap, lava clay, baking soda, vinegar rinses or just water. Radical teetotalers count themselves among the “NW/SO” subgroup, which means “No Water/Sebum Only” – no water of any kind is allowed on the hair. Especially long-haired women belong to the movement. They used to be outsiders, but now Hollywood’s celebrities swear by them: Adele, Jessica Alba and the Olsen twins all profess to have greasy manes. The method is said to have the following advantages:

The hair stops being greasy. Indeed, they do so only because shampoo always removes the natural protective film.
Without chemicals, the hair becomes healthier, stronger and shinier.
The method is environmentally friendly because no chemicals get into the water.

What is fact? Hair washing is the most common form of hair treatment. Its purpose is primarily to cleanse the hair and scalp of sebum, keratin debris, sweat residue, dust and odors. Until the introduction of the first alkali-free hair shampoo on the market in 1933, soap alone was available for washing hair. It was conceivably unsuitable. Due to their sensitivity to lime-hard water, with which insoluble lime soaps adhering to the hair surface are formed, making the hair dull and lackluster, and due to their strongly alkaline pH with a corresponding irritating effect on skin and mucous membranes, soaps for hair washing have been successfully replaced by today’s standard, synthetic shampoo surfactants.

What do today’s shampoos do?

The requirement profile that is placed on a shampoo today far exceeds the function of mere cleaning. Shampoos are also expected to be not too degreasing, to have foaming properties in hard and soft water and in the presence of grease, to be well tolerated by the skin and mucous membranes, to be chemically and physically stable, to have conditioning effects, to be biodegradable and to be inexpensive. The shampoo should cosmetically enhance the hair, be tailored to the needs of different hair qualities, age and individual washing habits, while favorably affecting specific problems of the hair and scalp.

Accordingly, since 1933, shampoos have evolved into high-tech products consisting of 10-30 formulation ingredients. These are put together in finely tuned proportions so that the product satisfies the consumer. From concept to saleable shampoo, it sometimes takes more than a year of development. Particularly invested in the development of care substances (conditioners), which should give the hair shine, smoothness, volume and resilience as characteristics of healthy hair. Another prerequisite for well-being is a scalp that is not too oily and free of dandruff.

Functions and consequences of sebum

Sebum keeps the skin from drying out and keeps the hair supple, thus has a natural conditioner function. However, depending on the amount of sebum, its composition and microbial colonization, sebum can give rise to scalp and hair problems: The oil- and wax-like ingredients of the skin fat weigh down the hair and reduce friction from hair to hair and thus the hair style. Accumulation of dust and dirt on oily hair, as well as peroxidative transformation of sebum, leads to prematurely dirty appearing and bad (rancid) smelling hair. Finally, depending on the microbial colonization, scalp dandruff, eczema (seborrheic eczema) and bacterial infections (folliculitis) of the scalp may occur.

The aim of shampoo treatment is to remove sebum and dirt, the elimination of which inevitably reduces the number of germs on the scalp, as these residues are an ideal breeding ground for microorganisms.

In order to maintain the natural state of freshly regrown hair for as long as possible, the sebum removed must be replaced with conditioning additives (conditioners) in the shampoo. All standard shampoos today are enriched with conditioning agents. These include: vegetable oils, waxes, lecithin and lanolin derivatives, protein hydrolysates (collagen, silk, animal proteins), quaternary ammonium compounds and silicones (dimethicone).

Health and environmental risks from shampoo use?

Finally, there is great public interest in knowing whether and to what extent the use of everyday substances such as shampoos poses health risks. What impact the use of organohalogen compounds, formaldehyde releasers and nitromusks in shampoos has on health and/or the environment is one of many issues that have been addressed by the media in the past. The product safety of a shampoo is first evaluated by assessing the data of all ingredients used with regard to skin and mucous membrane compatibility, sensitization potential, acute and chronic toxicity, mutagenicity, skin penetration and accumulation potential, biodegradability and aquatic toxicity.

What is certain is that the current propaganda of sulfate-, paraben- and silicone-free shampoos lacks any scientific basis and only follows a marketing strategy of alternative products.

Requirements for the environmental product safety of cosmetic preparations can be derived from the legal situation. From the point of view of water protection, priority is given to agents that enter water bodies. The prerequisite for the use of an ingredient is that irreversible disturbance of water bodies is not to be expected. For surfactants used in larger quantities, rapid and complete biodegradability is required from the point of view of reliable water protection. This has been extensively studied and confirmed, with knowledge of the ecological properties of surfactants resulting less from their use in shampoos, which are of secondary ecological importance in the quantities they are used, and more from studies of detergents and cleaners, which are used in much larger quantities.

Effectiveness review

Modern hair cosmetics are not only safe and compatible, but also take into account claims of effectiveness. The laboratories of the cosmetics industry have long since developed objective measurement methods for testing efficacy. Measurement methods include a large number of computerized and partially robotized methods that quantify hair cosmetic phenomena and efficacies such as build-up, bounce, body, hairability, tangling, damage genesis and conditioning. By the considered use of the available variety of methods, the refinement of the method park as well as the dialogue with experts of subjective tests at the end user, hair cosmetic effects can be described precisely and close to the consumer and optimized under consideration of practice-given and economic objectives. The testing of different hair types in appropriate climate chambers with different humidity levels has finally enabled the development of global hair care lines.

Conclusion

“No-Poo” represents nothing more than a step backwards into the hair cosmetic “stone age” in the absence of sound knowledge of modern hair care cosmetics and shampoo technology.

Conflicts of interest: The author has scientific consulting activity for (in alphabetical order): Apomedica, Asatona, Procter & Gamble, Rausch.