"Clarifying" sounds clean and clear -- but they can be rough on your hair, O'Brien says.
"Very few people will really need a clarifying shampoo," he says. They're generally used because someone has some kind of condition or is going to get a chemical treatment, and they really need to cleanse the hair. They rough up the hair's cuticle, for example, so the perm or color might take better. But some of them can be extremely harsh."
You should definitely avoid clarifying shampoos aftergetting your hair colored. "Even the mildest clarifying shampoos will unwind that color really fast," O'Brien says.
Shampoos for Color-Treated Hair
These shampoos are made to help make your color last. Acord recommends checking on the shampoo's "ph" level, which is a measure of how acidic or alkaline the product is. He suggests looking for a ph between 4.5-5.5 to help prevent fading. If the ph level isn't shown on the shampoo bottle, try searching the product's name and "ph level" online.
Good shampoos for color-treated hair may also use an ingredient like an oil, sea kelp, or algae to help color stay in your hair, O'Brien adds.
Want to refresh your hair without a full shower and blow-dry? Try a dry shampoo.
"They can really be a lifesaver and break that every day shampoo habit," O'Brien says. "Pump a burst [of dry shampoo] down your hairline, in the part, and at the crown, and take your blow dryer and brush and fluff it up, and you're probably out the door in five minutes."
The Buildup Myth
Whatever shampoo you use, you don't need to switch periodically in order to prevent "buildup." That's a myth, Acord and O'Brien say.
"The products are so good now that you aren't going to get a product buildup unless you're a crazy hairspray person, which is not how hair has been styled for the last 15-20 years," O'Brien says.
The best way to pick the right shampoo for you: Ask a stylist. "A runner shouldn't pick the right shoes based on what color they are," O'Brien says. "They should go to a running specialty store and get fitted for the best shoe. It's the same with shampoo. Don't pick your shampoo based on what your friend likes or because you like the fragrance. Get a recommendation from a stylist that knows your hair."