It’s all the same stuff…liquid detergent.
The only differences are scents and whatever herbal crap they add to make people think their product is superior. But the fact is, all shampoo is pretty much equal. We buy it by the quart at the Dollar store. Why do people who pay $12.99 for a little 8oz bottle of some premium “salon” stuff think they’re buying anything better than the dollar store stuff?
Advertising I would imagine.
I don’t know that I’d chalk it all up to advertising. For example, I can’t even think of the name of my favorite shampoo/conditioner blend, but I’ll recognize it on the shelf. It’s about $8 or so for some odd quantity of fluid ounces.
Try washing your hair with laundry detergent or just a bar of soap sometime. You feel the difference when you’re done?
I once washed my hair with dish detergent in college when I found myself out of shampoo. Wow, did I get dandruff something fierce despite rinsing it out well.
I used to date a hair stylist. I asked her about this once, but not in great detail. Essentially, it was her understanding that a brand like Paul Mithcell contained ingredients that actually helped your hair and scalp. A brand like Prell or Suave off the supermarket shelf did not and was basically crap shampoo.
My impression from the discussion was essentially that saying all shampoo is just scented detergent is like saying all pizza is just bread and toppings.
Because it’s not.
Nothing wrong with using a bar of soap for shampoo.
As long as its Kirk’s!
I will be using just that for a week in hunting camp.
and I will be washing clothes with Fels-Naptha heavy duty laundry bar soap
For the OP: CITE???
Some shampoos have different ingredients for different types of hair-like if you have curly, course, dry hair, it has more moisterizers. If, on the other hand, you have very baby-fine, straight, oily hair like mine, it has additives to give it more body. Clarifying shampoo (I use it once or twice a month) washes out all the build up of styling products.
All shampoos are not created equal.
Bar soap in one’s hair cakes up horribly and can make a big time mess. Yuck.
As for the scents-uh, that makes my hair smell nice. I like my hair to smell nice. Got a problem with that? 
I used dish detergent for a few months because I was too lazy to buy the real stuff. It cleans your hair all right but it seems to strip everything off of it as well which is not good. I have used Ivory soap as well. It works too but it leaves your hair feeling a little icky. I like either the shampoo/conditioner combos or Johnson’s Baby Shampoo for myself these days.
I was married to one, and she said the same thing. Of course, she never really knew WHAT the difference was, just that expensive was better. Of course, she got paid commission on selling product, so there’s a certain bias there.
I’ve been using cheap Suave or Pert for years, and I can’t stay it “ruined” my hair, as she promised it would. I’ve no doubt that expensive stuff smells better, but I think the stylist claim that cheap stuff will ruin your hair is dubious.
Wait, so you are paying for all kinds of additives. Then you need another product to wash all the “buildup” of those same additives out? 
Build up of hairspray and gels if you use them. Not the build up of shampoo.
I’ve used many shampoos in my lifetime and they certainly aren’t all the same. The gallon stuff that my mother used to buy when we were kids was like dish detergent and stripped our hair so much we walked around with frizz heads all year.
There actually is a difference between different kinds of soaps. Presumably some soaps are better for different things, and some people feel they are worth the extra money. I don’t know, I’m not an expert.
I’ve been meaning to ask a similar question for awhile now, but I didn’t quite know how to phrase it tactfully. Essentially, how many commercial ‘dermatological’ products are just bullshit?
There are so many expensive creams, soaps, oils, mud and whatnot for your skin and hair and it seems to me like the differences are minimal. Does my hair really need a separate kind of soap than my body? Do I need a dedicated face wash? Do any acne products work at all? What the hell is a ‘moisturizer’? Just another word for lotion?
The OP claims to know the answer, at least when it comes to soap-like products, but others have disagreed. I’d like to see some evidence that these products do what they claim to do, or that they don’t. As a lifelong user of (the cheaper kinds of) these products, I have to say my experience is inconclusive.
Here’s an article all about what’s in shampoo and how it works: http://findarticles.com/p/articles/mi_m1370/is_v18/ai_3290522
and another one that’s less helpful: http://www.virtualsciencefair.org/2005/wali5s0/public_html/faq_page.htm
And a book chapter: The Science of Hair Care - Charles Zviak - Google Books (Chapter 2)
Yes.
My guess is that you have very short, straight hair with a shaft of medium thickness - perhaps that’s why you don’t notice the difference.
Expensive is not always better…some expensive is horrible, some cheap is very good. But no, not all detergents are alike, and not all shampoos are alike.
Not the shampoo, but all the styling products I use-gel, hair spray, etc-just to give my hair some body.
Everyone’s skin and/or hair is different. For example, I use Noxema on my face, but my mother needs to use cold cream to take her make-up off. Others use Clearisil.
It all depends on your hair and/or skin type. Again, some people have very thick hair. Some people have curly hair. Some have oily hair. Ditto for skin.
What kind of shampoo do you use, and what type of hair do you have? Are you male or female?
(I use Pantene Pro-V, and twice a month I use Queen Helene’s Mint Julip concentrated shampoo. I also use Garnier styling gel to give my hair body.)
Several posters have mentioned bar soap in this discussion.
Soap and detergent are two completely different things. The OP never mentioned soap.
As far as various brands of shampoos go (which are all detergents), Consumer Reports has reported many times that all shampoos are basically the same.
There are many shampoos made for people with dandruff, psoriasis, and related conditions that are not simply liquid detergent.
I’m not horribly particular about shampoo, but I will also say that washing my hair with dish soap leaves it feeling “wrong” - kind of all stiff and wiry. Let’s not forget the conditioner, either. I want to be able to comb it after showering without it being a knotted up mess. Since I’m not particular, I just buy the cheapest shampoo + conditioner in one bottle.
From http://www.gina.antczak.btinternet.co.uk/CU/CUFAQ.HTM
*Q: Why are there so many ingredients used in cosmetics and toiletries? Nine times out of ten the list of ingredients is huge.
A: In fact the list is even bigger than it looks. The word, Fragrance in the USA or Parfum in the EU, refers to a mixture of fragrance chemicals, seldom less than fifty in number and commonly more than a hundred, most of which are artificial. If they all had to be listed individually, shampoo would be sold by the gallon in order to fit the list of ingredients on the bottle.
We like to divide the ingredients into five different groups. The first group are the functional ingredients, without which the product would not work. Shampoo would not clean your hair if it did not contain a detergent and a sunscreen would not protect you from harmful ultraviolet rays if it did not contain UV absorbers.
The next group are the presentation ingredients. These give the product the right feel, smell and appearance. For example, a bar of moisturising soap should both feel and smell luxurious.
The third group are the preservation ingredients. These stop the other ingredients from separating or prevent microbes growing from in the product, thus protecting you harmful bacteria and giving the product a long shelf life.
The fourth group are the trivial ingredients which have no function other providing the manufacturer with a marketing gimmick. These are easily identified because the ingredient features strongly in the advertising and the banner label but are usually placed near the end of the list of ingredients because they form a very small part of the formulation. They include a host of natural extracts, proteins and vitamins to name but a few.
The final group are the unnecessary ingredients. These are added for the convenience of the manufacturers and include such things as lubricants to prevent the product from blocking pipes and tubes in the machinery, anti- corrosion agents to prevent the manufacturers’ machines from rusting, anti- foaming agents to prevent a build up of foam during manufacture and various solvents and carriers used to add other ingredients to the product.