You know the feeling when your hair doesn't seem to get clean or feel healthy no matter how many times you wash it? I struggled with this problem for years before I finally figured out a solution. When I was younger and I would get this build-up I would call the conundrum "shampoo-y eww-y." It just felt like every product I used would get stuck in my hair and even if I changed shampoos and really took the time to wash and dry my hair, it would still look and feel greasy.
A few years ago, I finally googled this phenomenon and found out that all I needed was clarifying shampoo and my life was changed (well, at least my hair life). Whenever I get the feeling of build up and residue, I wash just once with clarifying shampoo and my hair is restored to a softer and healthier state. It makes your hair feel lighter and bouncier and brings back it's natural shine. If I get a blow-out or up-do for a special occasion and use a ton of hair spray, I will use it the following day to really wash out all of the product. I've also found that if I travel to places with hard water that this helps combat how my hair reacts to the switch. The great thing about the shampoo is that you only have to use it once in awhile to really make a difference. In fact, you shouldn't use it too often because it will dry out your hair. I have pretty thin hair and use it about once a month, but other friends of mine, who have thicker hair, use it up to once a week.
There are tons of clarifying shampoos on the market, but I swear by the cheapest, most accessible one - Neutrogena Anti-Residue Formula. It's available at most drug stores, is under $8 and, after trying some fancier brands, I've found it works the best and produces the most results. The one down side is that I can't stand how it smells. Luckily, I only use it once a month so it's not a deal breaker for me.
Another option I like is the Clarifying Shampoo from Moroccan Oil. I found this one was almost as comparable to the Neutrogena, but not as strong. The up side is that smells great, just like the oils they make. If the Neutrogena shampoo is too strong or is drying out your hair, this might be the better option for you!
I swear by clarifying shampoo so much that I've been known to pour mine into travel bottles and hand them out to friends. So if you need to restore your hair and remove all that gunk we put in our hair daily, try it out! Or come on over and I'll give you a sample!
(Various websites warn people who color their hair that clarifying shampoo can strip or fade the color, but I have colored my hair for years while using these products sparingly and never noticed a change, but I felt like I should warn anyone who colors their hair!)