Many trends in the cosmetics industry are helped along by companies and manufacturers carrying out intensive research, then constantly improving their products. The "clean beauty" movement also benefits from this approach. When it comes to the "no shampoo" trend, though, it doesn't work. The whole idea is to do without shampoo altogether.

Not everyone is on board with giving up shampoo. People with a normal, healthy scalp may well be able to handle it. But: those with scalp problems, such as an itchy, oily, dry and sensitive or flaky scalp, can encounter problems, even malfunctions. For example, an imbalance in moisture, the way sebum changes on contact with the air and/or the metabolites of sebum produced by the microorganisms on the scalp can lead to itching and/or a dry or irritated scalp. 

In a study conducted by scientists involving a research team in Antarctica and astronauts on the International Space Station – neither of whom could wash their hair – they found that the microbial levels on the scalp increased 2–3 fold. This increase in the concentration of malassezia led to much more itching and dandruff formation. 

Dermatological studies have also found that using shampoo clearly improves some scalp conditions. More information:  "The Impact of Shampoo Wash Frequency on Scalp and Hair Conditions" .

pH value of the scalp must be observed

You might think that a flaky scalp is the result of a scalp that is far too dry. In fact, while unpleasant dandruff and itching can occur on a dry scalp, it can also affect and cause problems on an oily scalp. Water alone cannot help clear this issue. The skin and hair need help. In any case, careful skin and hair care with suitable products is important. If problems such as dandruff, redness or itching cannot be resolved with regular care routines, we recommend that you consult a dermatologist. 

What's more, many people are not aware that the benefits of “No shampoo” are not actually scientifically proven. However, that doesn't necessarily mean it can't work. But: Some of the methods used can be harmful. For example, if baking powder and apple vinegar are used for “hair care” but are not sufficiently diluted, this can have an adverse affect on the natural pH of the scalp. It will irritate the scalp and cause negative changes to hair structure. 

However, as we repeatedly emphasize in many of our articles, not everyone is not the same, and everyone has their own personal wishes and needs. Everyone has to decide for themselves what works for them and what they like best. 

Exceptions confirm the rule

Of course, we recommend using shampoo and related products for appropriate care, but using more shampoo does not necessarily mean better results when washing your hair. Watch how much you use. For medium-length hair, an amount the size of a golf ball or walnut is sufficient. Likewise, washing multiple times may not be necessary. Exceptions may prove the rule here, of course: if your hair is extremely dirty or has been treated with a lot of styling product, it will be grateful for a rinse and repeat. Shampoo ingredients also differ, and you may tolerate one shampoo better than another. Trying new products out now and then is useful.

All our reports on the Internet have still left a few questions unanswered, so we asked our colleague Dr. Annette Mehling – Senior Manager, Skin Sciences, a BTS and Eurotox-registered toxicologist at BASF – to give us the answers. 

Annette, we often read that regular shampooing affects the production of sebum on the scalp. Others claim that sebum production depends only on the individual. Which is correct? 
Annette: There is no easy answer to that. Many factors play a role in the production of sebum on the scalp. Most people are probably aware that when an individual reaches puberty, their sebum production increases due to hormonal changes. There are also studies showing that ethnicity and gender play a role. There have not been enough controlled studies conducted over a long period of time to be able to provide a certain answer. 

We’ve often said no one needs to be “afraid” of the ingredients found in cosmetic products. Can you give us a short, snappy statement in favor of using shampoos?
Annette: We all have certain wishes and needs when it comes to our hair. Shampoos are developed and formulated with these requirements in mind. They allow us to care for our hair and keep it looking healthy. Personally, I find one thing especially important to mention in this context: in the EU, a safety assessment is carried out for all cosmetic products, including shampoos. The use of various ingredients, such as preservatives, is heavily regulated and some substances are prohibited (1,328 substances were prohibited as of the end of 2022). In other words, you really don't have to worry about safety. 

Not washing for weeks sounds messy and gross. What exactly happens to the hair and scalp if you don't take care of it? 
Annette: Again, it is very difficult to give a clear answer. It depends, for example, on what ends up on our scalps, what environmental influences we are exposed to, and whether any medical conditions may be present. Hormonal status also plays a role. Sebum ingredients may be broken down by microorganisms, for example, especially if too much sebum is produced. This may create free fatty acids that can irritate the scalp. When we are exposed to heavy pollution, the pollutants can also affect the health of our scalps. When it’s hot and you sweat a lot, the healthy pH of the scalp can change. Some people bleach or dye their hair, which can also affect the scalp and irritate it. Cleaning and/or care makes sense here. Some people have long hair, others short and others none at all, and some have very fine hair. All of these factors can lead to different reactions to care products, for example, if shampoos are difficult to rinse out residues may remain on the scalp. This can cause irritation, or may also be nourishing. However, I am sure you can imagine situations in which you can do without shampoo, and water alone is sufficient. 

Should people with greasy hair wash their hair more often or less often? 
Annette: It is not enough simply to look at the greasy hair to decide what to do. It also depends on what causes it, and your living conditions. It’s probably better to wash your hair more often. This doesn't mean several times a day. Several times a week is likely to be enough. There are studies that show once daily leads to more beautiful hair and the people taking part in the tests said their scalps felt better. Always bear in mind that nothing much will change straight away. Change – whether an improvement or a deterioration – tends to be a gradual process. 

Thank you, Annette, for taking the time to answer these questions, so that we can cross them off our list. 

Things are not always black or white. Everyone has their own, unique skincare and haircare needs. Find the right self-care program for you. One thing’s for sure: care is important and necessary. And just as individual as we all are.